GroupDIY

Project Specific Discussions => Dynamic Processors => Topic started by: hairyandy on June 04, 2004, 11:03:11 AM

Title: GSSL HELP THREAD!!!
Post by: hairyandy on June 04, 2004, 11:03:11 AM
------Thread Header------
I don't quite know where to start fault tracing. Anyone got a clue?

Yes - read this thread, looking for something similar. This help section is not meant as a online help-chat, but a place to look up fixes to various problems

I fully understand it's a long read, but there is so much great information and error-tracing information collected here. No matter how the outcome, you'll learn important things from this.

When you eventually solve a problem in the GSSL, please don't be shy: Post a short description of your original symptoms, what the fix was, and how you found it. This would be of tremendous value for others stumbling over the same stone..

And oh - don't worry too much: With patience and work, there is a very high success-rate on this project.

Jakob E.

------/Header------


Hey guys,

I just got my PCBs from Gustav last week and then the forum sh*te happened!  Does anyone have the entire SSL help thread backed up?  I'm not necessarily asking for it to be posted here, I'd just like to get it to have locally when I begin this project.  This is my first DIY project.  BTW, you guys all rock!    :grin:

Thanks,
Title: SSL HELP THREAD!!!
Post by: Bauman on June 04, 2004, 11:59:33 AM
So just to recall, are you guys using THAT2180LA without a problem on the SSL compressors??
I'm about to buy some and would like to know, since we don't have that good old data...

cheers!
Title: SSL HELP THREAD!!!
Post by: gyraf on June 04, 2004, 12:03:56 PM
Attention:

This thread is an archive of possible and tried problems and solutions - NOT a help chat.

Try to go through this thread looking for answers before posting questions - that way there's a better chance someone will be happy to answer.



___________________

Hi Andy,

Welcome to the Lab, and the addicting world of DIY. You'd be hooked before you know..

We're all here (even a collection of highly estimated design engineers from well-known companies) - just ask, and we'll try to answer...

Jakob E.

Fabio: 2180LA works fine for the Clone, as does -LB
Title: SSL HELP THREAD!!!
Post by: ChrisA on June 04, 2004, 12:04:40 PM
I'm using the 2180LB and it works fine...You should be fine if you use the LA...Are you dealing directly with THAT Corp to buy them?

If we just start another SSL help thread, it will probably grow very informative in a matter of a few days....we should just do it.

Jakob, would you care to start off the thread? would seem most appropriate...

Chris
Title: SSL HELP THREAD!!!
Post by: Bauman on June 04, 2004, 12:07:42 PM
Thanks Chris and Jakob!

Going to get some LA fro http://www.profusionplc.com :)

cheers!
Fabio
Title: SSL HELP THREAD!!!
Post by: gyraf on June 04, 2004, 12:16:20 PM
Chris,

This thread is as good as any.. let's just keep it here...

Andy - could you remove (edit) the questionmark from the thread title?

:grin:  

Jakob E.
Title: SSL Meter
Post by: keithcamilleri on June 05, 2004, 02:05:35 PM
Hi guys...

I am still gathering parts for the SSL clone, and I am at a point to buy the meter, can anyone help me out?

I liked the one tha Jakob has on the site but I don't know the company who produces it, otherwise I had in mind the SIFAM AL29WF, but I cannot find the specs for the meter?

cheers
Title: SSL HELP THREAD!!!
Post by: gyraf on June 05, 2004, 02:51:43 PM
Hi Keith,

Welcome here.

For the meter to the SSL you'll need a linear 1mA fsd type, NOT a VU-meter.

And you need one that will fit in your box. Sifam AL29 will fit in a 2U, not in a 1U box.

Sifam "Presentor" data found here: Http://www.sifam.co.uk/presentor.lasso

RS components has the Sifam linear-scale meters. The original SSL meter was a Sifam.

For 1U boxes, you'll need a different meter type, something like this:

(http://www.herrong.com/CF20_EDGE.jpg)
http://www.herrong.com/CF.htm

RS components has the Kyoritsu EW-60 (order no. 143-3287 - about 34£) that should fit in a 1U box - but better check measures for yourself before buying...

(http://img-europe.electrocomponents.com/images/DK143323-01.jpg)

Farnell also has these cheap standard types:
(http://uk.farnell.com/productimages/farnell/thumbnail/PAN12SA.jpg)
order no 143509 - it's 100uA, but will work with a different meter resistor (20K in stead of 2k)

Jakob E.
Title: Thanks :-)
Post by: keithcamilleri on June 05, 2004, 03:07:42 PM
Hi Jakob...

I appreciate your help a lot... I am new in DIY ...but I am already hooked on it .....it is very easy to get hooked as you well said ....   :-)

regards
Title: SSL HELP THREAD!!!
Post by: hairyandy on June 06, 2004, 05:04:25 PM
Thanks for the info on the meters Jakob.  I've been wondering what to get and have been balancing the cost vs. cool factor.  I think I'm now down to the Farnell #143509 or the Behringers.

On a different note, I just got a dbx 202C for my clone and I have two 2150s available to me as well.  Is it OK/possible to mix different vca types in the clone?  I'm assuming that since they're interchangeable it's possible but will it adversely affect the sound at all?  I'm thinking that I should use the two 2150s for the inputs and the 202C for the sidechain.  Would that be OK?  Does anyone have an opinion about 202 vs. 215x or 218x as far as sound quality is concerned?

Thanks and sorry if these questions have been answered before...
Title: SSL HELP THREAD!!!
Post by: gyraf on June 06, 2004, 05:32:23 PM
Andy

You can't use the 202 for the sidechain, as the 202-block option is only for the two audio-VCA's.

The 202 is simply too good to be used as a humble predictor-VCA, that noone will ever hear - so here it is 2150/80 only   :grin:

And you shouldn't use one channel 202 and a second channel 2150, as even small differences can and will disturb your stereo imaging.

Save your 202 for a later project - I'm pretty sure that you will need it one day..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: hairyandy on June 06, 2004, 05:38:51 PM
Thanks again Jakob.  Exactly the info I was looking for...
Title: SSL HELP THREAD!!!
Post by: ChrisA on June 07, 2004, 05:26:51 PM
so are the dbx202 vca's more desireable than the newer 2180/2150 series thats?

I thought they were older and inferior to the new ones...
Title: SSL HELP THREAD!!!
Post by: ChrisA on June 08, 2004, 04:02:39 AM
Hey Jakob,

would the sifam presentor meters work?

It looks like the AL19 would fit, but is it linear 1mA fsd type?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 08, 2004, 04:17:00 AM
ChrisA,

The 202's are nice stuff. The 2181's have at least as good specs. The 2150 is a low-cost solution - although with a nice sound.

The Sifam range of meters - like any meter manufacturer - can be had in all sorts of FSD values. You just order the type you like, and specify a  FSD sensitivity, 1mA in this case.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: ChrisA on June 08, 2004, 04:28:05 AM
Thanks Jakob.

I think I found a store here in Los Angeles (where I am) that has the sifam presentors and just shot them an email.

I still have no meter on my first ssl and just started building 3 more, so I thought I'd better get on this.

cheers,

Chris
Title: SSL HELP THREAD!!!
Post by: tubejay on June 08, 2004, 08:00:25 PM
Hopefully someone who's built one of the on 120v can help me sort through the power situation on the SSL.  I'm getting ready to order the parts for this, but everything I've read seems to be based on 220v power.  Would anyone be so kind as to tell me what I need to do differently in the power supply section to make this work properly.  I'm new to this, so please forgive the basic question.  Again I don't necessarily get this, but from what I've gathered, the only thing that should be different is the power Xformer...right???

Also, if you could include part numbers, like for what transformer you used, or anything that might be different from the PCB I have, which is the one from Gustav.  

Thank you!

Jimbo :guinness:
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on June 08, 2004, 08:33:36 PM
I used the Digikey part number TE62063-ND
It works great! Nice, small toroid. Just make sure you've got a nice fuse, power switch, and IEC connector and you're golden.

Ian
Title: SSL HELP THREAD!!!
Post by: tubejay on June 08, 2004, 08:38:19 PM
Quote from: "Ian MacGregor"
Just make sure you've got a nice fuse, power switch, and IEC connector and you're golden.

Ian


Thank you for the info!  Not to be a total pest, but do you have the part numbers you used for those three parts?

Thanks!!!
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on June 08, 2004, 08:53:52 PM
Well... You can get a 5x20mm fuse anywhere, I'll give you the number of the fuse holder I used. All mouser part numbers:

Fuse Holder: 5767-345531
IEC Connector: 693-6100.3300
Lighted Switches (expensive!): 653-A165L-AGA-24D-2

Just buy a 1/3A (or so) 5x20mm fuse and you're set.


Ian
Title: SSL HELP THREAD!!!
Post by: tubejay on June 08, 2004, 10:42:40 PM
Holy sh*t, those power switches are expensive!  WTF!!!  Oh well, they look pretty cool!  The round one kind of reminds me of the Presonus MP20 power button...at least that's what the picture from the manufacturer looked like to me...

Ok, so now I'm to the semiconductor portion of the list.  I can't seem to find just a plain NE5532 on Mouser or Digikey.  Anyone have any recommendations here?  This is my first time ordering opamps, so it's a sea out there.  I see tons of ne5532 designations, but all are followed by a letter, such as D or something.  I guess I'm having the same problem with the TL072, TL074, and NE5534-AN as well.  I'm not understanding all of the suffixes after the main number (like TL072ID).  What does the ID mean?  

Lastly, (I hope) for the W04 Rectifier, will this part work:

http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=237465&e_categoryid=236&e_pcodeid=62504

I know I promised that was the end...but then I got to the regulators.  Can anyone steer me in the right direction here?  I was on Digikey, and it looks like there's several possible candidates for the job, so that scares me.  Does anyone have their parts lists available that ordered in the states?  I promise when I'm done, I'll put a website for this, and include part numbers and everything in return for the favors, so in the future we can direct people to that site for help with the parts...

Thanks again VERY MUCH!!!
Title: SSL HELP THREAD!!!
Post by: hairyandy on June 09, 2004, 01:35:22 AM
I think that's a great idea.  Take the parts list and add the part# and source (Digikey, Mouser, etc.) to the list as well as price.  That's what Tim Ryan's lists are like on SCA (http://www.seventhcircleaudio.com).  If anybody is game, I've got the webspace to host it...
Title: SSL HELP THREAD!!!
Post by: Plexibreath on June 09, 2004, 01:48:57 AM
So is the Meta thread just the holding place for information gathered in working threads like this one?

I was going to ask about the SSL in the Meta thread but since this one looks like it's floating on top I'll post here.

Anyway, so down the road I'll want to build a high end compressor.  I know the reputation of the LA2A, the 1176 and the Fairchildren, I also know about the SSL mega consoles, but is the SSL really a classic like these others?  What make it special, gives it it's reputation, and why would I choose it to build over say a 1176?  My main uses for a compressor will be for 3 mic tecnique for drums and stereo bus mix down.  Is it a side chained 2 compressor for stereo mixdown or mono?

Thanks,
Kelley
Title: SSL HELP THREAD!!!
Post by: Plexibreath on June 09, 2004, 01:58:48 AM
Duhh, I just saw the schematic, it is stereo with side chain.  Still, tell me more.
Kelley
Title: SSL HELP THREAD!!!
Post by: caps on June 09, 2004, 02:08:18 AM
If you use a standard face DCmeter like the one above rather than the edge type, you just got to be aware of one thing.

I chose not to use a edge meter and got a DC Sifam type, because I wanted to add my own scale, you can remove the backing on the Sifam meters and stick on your own scale or whatever. Anyway, in a 1U box you actually have to cut a slot out of the bottom of the rack case to make it fit. Helps here if your rack enclosure is made of aluminium!! Its not a big deal, cut the slot out so the bottom of the meter runs flush with the rest of the casing. It JUST fits, but looks good. Then you can just run a bit of tape across the bottom of the meter.

Just to let people not to panic like I did when you get around to sizing it up and thinking its not going to fit. :0)
Title: SSL HELP THREAD!!!
Post by: caps on June 09, 2004, 02:11:31 AM
The Sifam meter I used is of the Presenter series I think. Chris mentioned this one above. A good meter you just got to get crafty to make it fit as I said. :0)
Title: SSL HELP THREAD!!!
Post by: ChrisA on June 09, 2004, 04:47:27 AM
Hey Plexibreath...Heres a good read about the various different kinds of compressors

http://www.tangible-technology.com/dynamics/comp_lim_ec_dh_pw2.html

You really just have to hang around in the right places to truly develop an understanding of a specific piece of gear like this. Theres too much history to try and fill you in about everything.

Tip:
Look at the name of the studio where albums you like have been mixed. Find out what kind of console the albums were mixed on there. Find out more about the consoles and how people use them.

try gearslutz.com...its more suited for that type of discussion.
Title: SSL HELP THREAD!!!
Post by: tubejay on June 09, 2004, 10:46:32 AM
Quote from: "Plexibreath"
So is the Meta thread just the holding place for information gathered in working threads like this one?

I was going to ask about the SSL in the Meta thread but since this one looks like it's floating on top I'll post here.

Anyway, so down the road I'll want to build a high end compressor.  I know the reputation of the LA2A, the 1176 and the Fairchildren, I also know about the SSL mega consoles, but is the SSL really a classic like these others?  What make it special, gives it it's reputation, and why would I choose it to build over say a 1176?  My main uses for a compressor will be for 3 mic tecnique for drums and stereo bus mix down.  Is it a side chained 2 compressor for stereo mixdown or mono?

Thanks,
Kelley


You're right, I think we went meta to split this stuff up a little better...  I'm going to start a new post specific to US people looking for parts.  I think once the post gets to a certain length, people no longer read it.
Title: SSL HELP THREAD!!!
Post by: Greg on June 11, 2004, 04:50:06 PM
I just powered up my clone (keep in mind I didn't connect the I/O, VU, or Control PCB). The secondary on my power transformer is reading 35 VAC. My rails are:

+14.84 VDC
-15.04 VDC

+12.32 VDC
-12.04 VDC

Should the +14.84 be of any concern? Thanks,
Title: SSL HELP THREAD!!!
Post by: kent on June 11, 2004, 04:52:57 PM
OK fellas, I'm still tryin to wrap my clone up.  After fixing loads of solder bridges and broken traces (my worst etch ever) I've got it down to one last problem.  Bypass works fine.  When switched in the meter reads that compression is happening all the time even with no input.  In fact the meter goes up as you increase the threshold (a clue, I hope) with no signal.   It is compressing, too much, and the controls all work but even running in -10 and low ratio and high threshold it slams.  I've lifted all the resistors in the SC to check values and they are correct.  I'm sure it's another solder bridge or something but if I look at it one more time I'm going to go blind.  I need a way to eliminate the working stuff so I can trace to the problem.  Two things are throwing me for a loop.  Since it's feedback style compression just tracing back doesn't help since the problem could still be at the other end of the chain.  I'm also a novice when tracing DC.  AC signal is one thing but you can't put DC on a scope.  I know this is sort of a long winded post but please help.

cheers,
kent
Title: voltages...
Post by: pghedges on June 11, 2004, 06:32:33 PM
hmm... just powered mine up too. i'm getting 17.5v on each side, but no juice at the "power on" led. hmm.
Title: SSL HELP THREAD!!!
Post by: Greg on June 12, 2004, 05:33:38 PM
Maybe the last few posts got lost in the mix of things, so I'm going to give this a little bump.
Title: SSL HELP THREAD!!!
Post by: RemcoV on June 13, 2004, 06:07:22 AM
Greg: you rails seem fine to me. i would connect the control PCB and see if that works aswell.

PG: that 17.5V, where is that measured? regulated or from transformer...
if that's regulated it's something to worry about

Remco
Title: Make-up Gain Question
Post by: Greg on June 14, 2004, 08:31:35 AM
From reading the PCB PDFs, it seems there are two options to defeat the makeup gain in bypass. One is to put that jumper on the Control PCB, and the other is to wire to two points to another pole that contacts when the bypass is out.

Is this correct?

I'm asking because I only have the jumper on the Control PCB, and am curious to know if I understand this correctly.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 14, 2004, 08:35:41 AM
If you have the jumper on the control panel, you have constant makeup-gain. If you wire in a part of the bypass switch, you'll only have makeup gain when the compressor is "in".

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on June 14, 2004, 08:37:49 AM
Ahhhhh, thanks for clearing that up !!!
Title: SSL HELP THREAD!!!
Post by: pghedges on June 14, 2004, 03:14:55 PM
hey remco... 17.5v is showing up from the secondaries of the transformer and, unfortunately, also on the other side of the regulators.
Title: SSL HELP THREAD!!!
Post by: Greg on June 14, 2004, 07:22:06 PM
So your showing appx 17VAC on the secondaries and 17VDC after the regulators? Possibly check the polarity again on your bridge rectifier? Or maybe your caps? Just guessing though.
Title: SSL HELP THREAD!!!
Post by: kent on June 16, 2004, 11:24:32 AM
OK, I'll make another attempt for some help but I feel a bit neglected lately :sad:

My meter reads as if I'm getting gain reduction which increases as I turn up (or down as it were) the threshold even with no input signal.  With signal it behaves the same way - as if the control voltage is going bonkers - but it IS compressing.  With the threshold maxed (or perhaps I should say minimum - should be no gain reduction) I'm getting what sounds like more than 10db GR and the meters reflect this.

I have lifted all the resistors around the TL072 and checked traces (many times) and it all checks out.  Since the sidechain is FB I'm having a ***** of a time tracing to the root of the problem.

If anyone has any ideas before I chuck this thing please help.

cheers,
kent
Title: SSL HELP THREAD!!!
Post by: Greg on June 16, 2004, 11:33:10 AM
kent - What type of meter are you using?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 16, 2004, 12:00:58 PM
Kent,

Look at the schematic.

Even though this is a feed-back design, there's no DC feedback path. This means that we are either looking at noise disturbing the sidechain, or one of the DC-blocking capacitors are leaking..

Check for DC at point "C" without signal. If there's DC here with no signal, then either you have some HF oscillation or the 22uF electrolytic in the input of the sidechain rectifier is leaking DC (the one after TL074 pin7).

Check DC at the output of the A/R timing buffer, TL074 pin8. This should follow the signal on point "C" plus some timing - metering actual GR.

The threshold pot only adds some extra gain to the sidechain VCA, so whatever messes up must be a signal present at the input of your sidechain.

Try tracing your signal through the unit - for both AC and DC.

Check your supply voltages - specially the +/-12V should be stable and noisefree..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: skrasms on June 16, 2004, 07:17:37 PM
Hey, does anyone know if  this  (http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=341715&e_categoryid=125&e_pcodeid=54101) meter will work? It says it's for 0-1mA DC and I know it'll fit in a single space rack case. I don't know how to tell if it's linear though. I'm pretty new to all this electronics stuff, and have never put a meter in anything, so please pardon any ignorance. If that meter doesn't work then does anyone know any others that can be found in America (aside from the Behringer) and will work?
Title: SSL HELP THREAD!!!
Post by: tubejay on June 16, 2004, 07:33:39 PM
I have a stupid transformer question...  I just bought this transformer:

http://www.digikey.com/scripts/DkSearch/dksus.dll?KeywordSearch

I'm getting ready to finish building the powersupply section of the SSL compressor, and am a little stuck on getting the transformer wired correctly.  I've never actually had to build a power supply.  Every project I've built in the past has either had an external supply or operated off of a battery (guitar pedals).

Here's my understanding of how I'd do it.

One, tie the yellow and red wires together, and then tie the black and violet wires together.  The yellow and red go to hot on the 120v outlet and the violet and black go to negative.  

Then I tie green and brown together.  Then red and blue together.  Those then go to the rectifier?  

It shows ground coming off of the middle of the transformer.  That's the part I don't understand.  Is that just connecting to the metal part in the middle of the transformer where the screw goes?

Sorry for the super basic question, but I've never built a power supply before.  So I've never had to wire a power transformer.

Thanks,

Jay
Title: SSL HELP THREAD!!!
Post by: gyraf on June 17, 2004, 06:38:52 AM
Skrasms,

Welcome to GroupDIY!

Yes, that meter will work fine, providing you get it in the mentioned 1mA version.

Tubejay,

That link dosen't work..


Jakob E.
Title: SSL HELP THREAD!!!
Post by: tubejay on June 17, 2004, 09:10:01 AM
Quote from: "gyraf"


Tubejay,

That link dosen't work..


Jakob E.


Sorry, that's Digikey part number TE62063-ND.

Thanks!
Jay
Title: SSL HELP THREAD!!!
Post by: Twin-x on June 17, 2004, 09:11:43 AM
If i don't wish to use xlr connectors how is the wiring for jack plugs? Erm to add to this i mean 2 pole offcourse so it will be unbalanced.
I don't use mics or anything. Just plain simple for my drum computers.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 17, 2004, 09:26:19 AM
On the input, connect XLR pin3 to ground, pin2 to tip.

On the output, leave XLR pin3 unconnected, and pin2 to tip.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tubejay on June 17, 2004, 09:37:58 AM
Quote from: "gyraf"

Tubejay,

That link dosen't work..


Jakob E.


Sorry, that's Digikey part number TE62063-ND.

Thanks!
Jay
Title: SSL HELP THREAD!!!
Post by: Twin-x on June 17, 2004, 09:38:39 AM
Quote from: "gyraf"
On the input, connect XLR pin3 to ground, pin2 to tip.

On the output, leave XLR pin3 unconnected, and pin2 to tip.

Jakob E.
Thanks but i don't really understand. According to the pcb layout on your site you have the pins that should go to the XLR plugs. I wish to use Female Jack does this mean i connect

bal input left + to tip jackplug left input
bal input right + to tip jackplug right input
bal input left - to ground jackplug left input
bal input right - to ground jackplug right input
bal input 0 remains unconnected

bal output left + to tip jackplug left output
bal output right + to tip jackplug right output
bal output left - unconnected ?
bal output right - unconnected ?
bal output 0 remains unconnected

Is this what you mean? I appoligize for this very noob question.
Title: SSL HELP THREAD!!!
Post by: kent on June 17, 2004, 12:25:01 PM
OOOOOOkay here's what I have so far:

There's DC after pin 7 on the TL074.  There's DC after the DC blocking cap of said pin 7.  There's DC at point "C" after the FWR.  THis all goes up and down with the threshold pot so it's not shorted to a power rail somewhere.
I swapped out the DC blocking cap on pin 7 of the '74.  No change.  Of course the meter goes back to "0" when this is removed.
The +/-12V supply reads OK on my DMM.
I'm thinking this must be the HF oscillation Jakob mentioned.  I have a scope which my father bought for my birthday so I'm still figuring it out.  He got it used and it only goes up to 500kHz.  Is this enough to find the HF problem?  If I stick it on the input to the sidechain I don't see anything.

kent

BTW - it's a B- meter
Title: SSL probs
Post by: Livingroom on June 17, 2004, 03:31:28 PM
Hi Kent.

I am having the exact same problem with my ssl clone. Measuring the DC at the same points gives the same result as you mentioned. If it's HF osc., then how do I get rid of it? Could it be some of the components around the 074 that causes it?

All voltage rails seem to be fine.. could it be a problem with the sidechain vca?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 18, 2004, 05:03:18 AM
A 500KHz scope should be plenty to find HF instabilities.

What voltage and polarity are the DC voltages around the sidechain rectifier input (before and after the 22uF)?

Be sure to mount the 22uF according to the polarity of the DC at that point.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on June 18, 2004, 02:48:10 PM
Tubejay:

My toroid is actually an Avel from Parts Express, but yours will do just fine. Here's what you need to do to wire it.

On the primaries:
Tie yellow and red together and that goes to your common (not GND).
Tie black and violet and that goes to the hot (115VAC/120VAC).

On the secondaries:
Tie red and brown together...
Then measure between green and blue and you should have approximately 30VAC.

When you go to connect to the Main PCB, the red/brown (which are connected together), go to the middle point of the three. Connect green to the outside and blue to the one on the inner part of the board.

Basically we're connecting the primaries is parallel and the secondaries in series.

Let me know if anything is unclear.
Title: SSL HELP THREAD!!!
Post by: tubejay on June 18, 2004, 03:40:36 PM
Thank you very much Greg!!!  That makes a lot of sense!

 :guinness:  :sam:  :guinness:  :sam:  :thumb:
Title: SSL Hum problem
Post by: Nele on June 21, 2004, 11:07:24 AM
Hi,

Just finished building my SSL clone. Works perfectly but there is a small hum problem. If I leave the input unplugged and turn up the make-up gain you can hear some hum. Is this normal? I have to turn up the volume to hear it but it is pretty annoying. It's also present with inputs plugged in. When I disconnect the switches-pcb it's gone but I suppose that makes sense (no controls..).

I've used a toroid transformer, tied chassis and mains ground to one of the input grounds. gave each input/output it's own earth from pcb.

Any suggestions?

thanks,
corneel
Title: SSL HELP THREAD!!!
Post by: Greg on June 21, 2004, 11:25:02 AM
Nele:

Regarding the inputs:

Do you have one wire from the board going to one input ground, which is then jumped over to the other, then chassis/GND.

Or do you have two seperate wires (one for each) coming off the PCB to the input connectors GND, then one of those going to chassis/GND?

Also, did you use nylon or plastic seperators/insulators between your standoffs and PCB?

Sounds like your have a ground loop of some sort.

Also, how do you rails look... any excess ripple?
Title: SSL HELP THREAD!!!
Post by: robomatique on June 21, 2004, 12:12:14 PM
Quote from: "Greg"
Nele:

Do you have one wire from the board going to one input ground, which is then jumped over to the other, then chassis/GND.

Or do you have two seperate wires (one for each) coming off the PCB to the input connectors GND, then one of those going to chassis/GND?



Just what I was going to ask, which is the right connection/grounding?

Robert
Title: SSL HELP THREAD!!!
Post by: Nele on June 21, 2004, 12:12:59 PM
I have two wires going from both input grounds to the board. Same with the outputs. I also tried using one wire but that made no difference.
Using separators also doesn't solve the problem.
btw: the hum disappears in bypass-mode.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 21, 2004, 12:41:43 PM
Be sure that your whole chassis is grounded. The sidechain is quite high-impedance and thus hum sensitive.

When you check for hum and noise, do so with shorted inputs to avoid external hum pickup.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on June 21, 2004, 01:32:20 PM
Quote from: "robomatique"
Quote from: "Greg"
Nele:

Do you have one wire from the board going to one input ground, which is then jumped over to the other, then chassis/GND.

Or do you have two seperate wires (one for each) coming off the PCB to the input connectors GND, then one of those going to chassis/GND?



Just what I was going to ask, which is the right connection/grounding?



From my understanding it's the first, but it might not matter. If you look at the GSSL I just finished, I only have 5 wires (red ones) coming from the input connector, then the input GNDs are jumped together, which then goes to my chassis. I did this as to attempt to create only one path to GND. You can see this clearly by looking at the pics I originally posted. Follow the link below if interested:

Greg's GSSL (http://www.groupdiy.com/index.php?topic=543&start=0)
Title: SSL HELP THREAD!!!
Post by: Nele on June 21, 2004, 02:11:58 PM
grounding all of the chassis might be a problem. I bought mine at thomann.de and it is painted with none-conductive paint. so there isn't a connection between the different parts that make up the case. I have the bottom and back plate grounded but this didn't make any difference.

could the problem be my capacitors? I used nichicon HD series for the 22uF ones. when I touch them in the input circuit you can hear an extra, louder and heavier hum.
Title: SSL HELP THREAD!!!
Post by: Nele on June 21, 2004, 06:39:45 PM
Hi,

I did some more testing. The hum is 50Hz so there is probably some grounding problem. As the hum is also present in bypass mode (less audible but cranking up the make-up gain explains the higher level in active mode) I suspect the input stage. Could it be that the input caps, 22uF, are responsible? It isn't the input plugs (jacks in my case) because on disconnecting the noise is still there.

Caps used are nichicon HD:
http://www.nichicon-us.com/english/seihin/pdfs/e-hd.pdf
Title: SSL HELP THREAD!!!
Post by: gyraf on June 22, 2004, 04:34:45 AM
Nele,

No, it's not the input caps.

Do you have hum even with inputs shorted to ground/0V?

If so, I would check the powersupply. Check that voltages are correct, and that the +/-15V are clean, without hum.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nele on June 22, 2004, 04:59:33 AM
with inputs shorted to ground hum is still there.

plus 15 V reads 14,97 V
minus 15 V reads -15,45 V

minus regulator used: KA7915

How do I check for hum in the powerlines without a scope?

thx, corneel
Title: SSL HELP THREAD!!!
Post by: gyraf on June 22, 2004, 06:16:41 AM
To me, it looks like your 7915 is problematic. They're rarely off by more than 0.2V when thry're allright.

---

You could maybe check for hum on the power lines with a 1uF polyester capacitor in series with a cable going to an amplifier, and a 10K resistor shorting from after the capacitor to ground. The capacitor lets AC through, but blocks the DC voltage.

Connect amplifier input ground to your device-under-test's 0V, and use the free end of the capacitor as a probe.

Remember to keep amplifier volume down, as there will be a VERY loud click when you attatch/detatch the "probe".

And don't use an expensive amplifier/speaker for this - there still is a real possibility that it can be damaged.

Maybe a cheap computer-type powered speaker would be a good tool for this?

A setup like that could also be used to trace signals through a circuit - making it much easier to trace errors.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nele on June 22, 2004, 07:49:09 AM
I replaced the 7915 and now it reads -15,24V. Still humming. Both regulators are pretty warm.
Might it be the transformer? I used a clairtronic 15VA 2 x 15V toroid.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 22, 2004, 09:09:50 AM
Check DC voltages at the outputs of the opamps associated with audio - the 5534's and the 5532's at the in/out section. DC should be less than ~50mV on all output pins.

How is your +/-12V acting?

How much hum do you have?

have you mounted the power transformer in some distance from the pcb? Does the hum change when you move the transformer around?

Do you draw supply current for a meter light? If so, how much?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on June 22, 2004, 09:13:52 AM
Quote from: "gyraf"
To me, it looks like your 7915 is problematic. They're rarely off by more than 0.2V when thry're allright.

Gyraf:

I asked this question a while back when I originally powered up my clone. My positive rail is giving me 14.87VDC. Would you suspect a prolem? I haven't noticed any hum or excess ripple. Does that seem low and do you recommend anything?

Thanks.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 22, 2004, 10:14:34 AM
Greg,

No, +/-0.2V is no cause for concern.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: kent on June 22, 2004, 10:53:36 AM
Alrighty, after having a long weekend away I've gotten back to my SSL problem so Jake, oh great guru of all things SSL (no offence, Keef), let me run these numbers by you.

these are with the threshold from CW to CCW respectively and no input signal:

pin 3 on SC VCA
.25V            -.05V
pin 7 of the TL074
-4.8V          -10.6V
after the 22uf blocking cap
-.04V          -1.04V
pin 1 of TL074
.5V              1.8V
junction of diode & 20k on TL074
.1V              1.2V
junction of diode & 1M on TL074
-4.4V           1V
pin 14 of TL074
-.4V              5V
"C" connection to PCB
-.2V              -4.7V
pin 8 on TL074
-.1V              -4.5V
pin 1 on TL072 (it's pin 1 on the schem but really pin 7 on layout - a minor annoyance)
-1.7V            -2.7V
pin 7 on TL072 (once again pin 1 on layout)
3.4V              -.8V

Threshold control sends a nice +/- 12V.  Nothing on the 2150 input (pin 1).  Also, it takes a big spikey jump right before I hit full CW but I'm guessing a flakey pot which I can change later.

Any insight?  I'm not sure what to look for if it's oscillation.  If it's supposed to look like a wave riding on some DC on my scope I don't see anything but I'm most certainly a newbie with that thing.

cheers,
kent
Title: SSL HELP THREAD!!!
Post by: gyraf on June 22, 2004, 11:20:52 AM
Kent,

If you have down to -10V on TL074 pin7, output of the sidechain vca I/V converter circuit, there surely is a problem here.

And it's a DC problem, not a oscillation problem.

First of all, replace the 22uF right after TL074 pin7, as the one there has been reverse-biased and is probably faulty. When mounting a new one, reverse it's polarity, so the plus side points away from TL074 pin7.

We'll need to look for the source of this DC voltage before the or at the sidechain VCA.

Try swapping the sidechain VCA with one of the audio VCA's to rule out a broken VCA. Bear in mind that they are mounted opposite ways around.

What DC voltages do you have before and after the two 47K resistors adding the sidechain VCA input together?

What DC voltages do you have on the two input NE5534's outputs, pins 6?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nele on June 22, 2004, 11:46:48 AM
Hi Jakob,

Here are my voltages:

NE5534 input (pin 6): -1,0mV and -1,6mV
NE5532 output (pin 7): 1.0mV and 1.3mV

12V seems ok: 12,08V and -11,90V. they do get pretty hot!

moving trafo doesn't help

no meterlight...

the hum is pretty low. only audible when cranking the mixer up all the way but it is noticeable.
Title: SSL HELP THREAD!!!
Post by: Svart on June 23, 2004, 01:40:18 PM
quick question on hooking up makeup pot and bypass switches.. the area on my boards are a little unclear how they should be hooked up.  anybody got a picture?
Title: SSL HELP THREAD!!!
Post by: Greg on June 23, 2004, 01:42:33 PM
Quote from: "Svart"
quick question on hooking up makeup pot and bypass switches.. the area on my boards are a little unclear how they should be hooked up.  anybody got a picture?


Did you look at the PDF from Gyrafs site that shows the PCB layout and component overlay? There are diagrams there that show how the pots and bypass switch are connected.
Title: SSL HELP THREAD!!!
Post by: Svart on June 23, 2004, 03:23:34 PM
thanks, i didn't see those before.  however i am looking to wire it up without makeup defeat or use a simple toggle switch.  is there another way to do this that what is shown?
Title: SSL HELP THREAD!!!
Post by: kent on June 23, 2004, 03:39:28 PM
Success :green: !!

After checking voltages on my input amps and seeing that they were happy I swapped the VCA in the sidechain.  Voila, happy meter.  I did a quickie sound check here at work and it all seems OK.  I'll do some better tests with my stuff at home but so far it looks good.

Thanks, Jakob.

cheers,
kent

... now on to that 1W amp!
Title: SSL HELP THREAD!!!
Post by: Greg on June 23, 2004, 04:06:37 PM
Quote from: "Svart"
thanks, i didn't see those before.  however i am looking to wire it up without makeup defeat or use a simple toggle switch.  is there another way to do this that what is shown?


If you don't want makeup defeat, then just use a jumper on the Control PCB. If you do this, you will always have makeup gain. If you want to use a seperate switch for makeup defeat, then just take the two points for makeup defeat out to a switch. That's exactly what is being done as shown by Gyraf... it's just that the bypass and makeup defeat switch at the same time.
Title: SSL HELP THREAD!!!
Post by: Svart on June 23, 2004, 05:59:57 PM
thanks, now that you mention it i see it.

cheers!
Title: SSL HELP THREAD!!!
Post by: Greg on June 26, 2004, 11:25:17 AM
Hi, I posted this in another thread but this is probably where it should've been posted:

I don't think I'm getting unity gain through my unit. I'm using the 27k resistors... it appears that I'm losing about 5 dB. I traced the signal after the debalancing stage to the 27k and nothing is lost there. It's odd becuase last night I was having the same trouble, then all of a sudden I was at unity gain. It seemed to go to unity gain after I did a big frequency sweep (but that could've been coincidence). So I powered it up this morning and I was back to the 5 dB loss. Any suggestions?

FYI - I used the unit and it sounds great. No distortion or crackling or noise/hum or anything like that.

Also, I'm using a multimeter so I'm only looking at RMS values because I don't have access to a scope at the moment. Is that ok?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 28, 2004, 06:56:10 AM
Greg,

Are you sure you have the balanced in/out's set correct when measuring with unbalanced test equipment? (-input to ground, output measured between + and -)

alternatively, try using your unit with a normal balanced input/output under "realistic" conditions and see how levels are..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on June 28, 2004, 01:50:00 PM
Quote from: "gyraf"
Are you sure you have the balanced in/out's set correct when measuring with unbalanced test equipment? (-input to ground, output measured between + and -)

I did have the - input to ground, but I was measuring between + and ground on the output. I'm guessing that's it. But I'll check just to be sure. As usual, thanks for the info, Gyraf.

Quote from: "gyraf"

alternatively, try using your unit with a normal balanced input/output under "realistic" conditions and see how levels are..

Will do.
Title: Clone vs The original
Post by: keithcamilleri on June 30, 2004, 05:04:37 AM
Hi guys...

I was reading up on the original Xlogic, and found that SSL use That2181LA (56 of them) and LT1115 as op amps.

I would like to ask why SSL use 56 of the THATS does it make the sound better? and can the circuit for the clone be altered to use the LT1115 since it is known to be the lowest op-amp available?

Thanks loads...
Title: SSL HELP THREAD!!!
Post by: gyraf on June 30, 2004, 05:22:21 AM
the 56 VCA's, is that for a complete board?

This compressor is based on our 4000E console, that uses 202-type VCA's. The 2150-mod works well. With 2181lA's, you'll be better off noise and distortion-wise than the original.

There would be very little gained by using different opamps. I've tried that with several types, and the basic sound stays the same. The VCA's contribution to "sound" is much higher than any of the opamp's.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on June 30, 2004, 09:59:10 AM
Gyraf:

Just to follow up on my previous post. I was measuring the output wrong. My GSSL is definitely at unity gain, and it behaves fine when operating with other balanced gear. I didn't have a session last night so I was able to use it on a variety of sources that were already recorded (ie kick, snare, drum buss, bass, some vocals). Still haven't tracked with it yet, but that will change after tomorrow.

I really like the auto release (especially for lower frequencies) setting and how the ratio behaves. It's alot easier to hear how the ratio alone effects the sound. If you don't mind explaining, how does the ratio work exactly? I think you mentioned previously it does some type of averaging?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 30, 2004, 10:04:39 AM
Hi Greg,

Good to hear that your clone is working right.

The ratio control does two things:

First of all, it alters the gain of the rectifier stage - so that the part of the signal that is higher than threshold gets different gains. Second, it adds an offset to the rectified signal, compensating for the lower threshold neded for the same average gain reduction at lower ratios. In this way, the average amount of compression is more or less the same regardless of ratio setting (providing that you feed the unit with about the right levels)

The different ratios sounds different because it reacts on different parts of the input dynamics.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Svart on July 06, 2004, 10:09:40 AM
Gyraf and everyone, i completed the population and wiring of two SSL clones over the weekend.  I have to thank Gyraf for his work with this compressor because it sounds amazing. In fact, I'm going to have to build a couple more to round out my busses!  Now for the bad part.  the second clone does not compress at all.  the makeup gain is at full and will not attenuate via the pot either.  It's like the controls don't work.  I populated these boards side by side so each are identical, with identical parts.  I haven't had a chance to take a good look at the reason it doesn't work but can anyone lead me in the right direction?

thanks.
Title: SSL HELP THREAD!!!
Post by: gyraf on July 06, 2004, 10:33:39 AM
Svart,

Check that you have the needed +/-12V voltages present.

Check that you have signal coming to your sidechain, TL074 pin7.

Check that you have DC varying with signal at the output of the sidechain, TL074 pin8

Check that pin 1 and 7 on the TL074 has DC varying with signal level as well as a superimposed DC signal from threshold (TL072 pin1) and makeup (TL072 pin7). These two are your VCA control voltages.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Svart on July 06, 2004, 10:47:50 AM
thanks,

I'll probably get to work on it tonight.  

now where did everybody get their cases?  I was looking at the par-metal ones.
Title: SSL HELP THREAD!!!
Post by: Greg on July 06, 2004, 10:55:33 AM
Quote from: "Svart"
now where did everybody get their cases?  I was looking at the par-metal ones.


Yes, I bought mine from Par-Metal. But I had to make small notches in the lip Par-Metal puts on their top and bottom panels to make enough space for the B* meter. You can't see the notch b/c it's behind the front panel. I used a Dremel.
Title: SSL HELP THREAD!!!
Post by: kent on July 06, 2004, 11:04:24 AM
I popped mine in an old ADA chassis that had a lip like the PAR METAL.  I figured I would punch the front panel and the box at the same time to put in the "B" meter.  I ended up bending both.  Hopefully with some paint it will look OK but I learned my lesson.

cheers,
kent
Title: SSL HELP THREAD!!!
Post by: Svart on July 09, 2004, 10:43:24 AM
just a report on my problems with the #2 ssl..  bad tl074.  replaced and all is well!  however i noticed something else while experimenting with the controls.  when the release is set to longest, there is distortion introduced into the signal.  anybody have a clue as to why?  I did use 10u instead of 6.8u on the front control board..
Title: SSL HELP THREAD!!!
Post by: gyraf on July 09, 2004, 10:46:39 AM
Svart,

I'm sure we've had this before:

Are you sure it's set to the longest (auto) release at pos.5, and not to the 6'th position where the switch stops, but where there's no electric release position?

Remember to program the release switch to stop at 5positions..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Svart on July 09, 2004, 10:49:31 AM
now that is interesting, because I didn't even remember to check that..   does anybody have a link to some directions for that?

thanks gyraf!
Title: SSL HELP THREAD!!!
Post by: gyraf on July 09, 2004, 10:52:55 AM
There's a washer with one "teeth" under the nut for mounting the switch, that acts like an end-stop. Take this out (it comes from factory set to "6" on a 2x6-step switch), be sure to turn the switch completely counter-clockwise, insert the washer again, it's teeth at the position marked "5". Now you have a 2x5-pos switch.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Svart on July 09, 2004, 11:01:00 AM
thanks!, and one more question i just thought of, how much current do these draw?  I was considering putting a pair of these in a 2u rack running from the same tranny and need to know if the one i have will work.

TE62053 from amveco, 1 amp.

and one more.. i swear! (for now)

i don't recall seeing the timings for the attack/release anywhere.  are they the same as the rack mount ssl compressor shown on the ssl page?

http://www.solid-state-logic.com/outboard/products/xgseries/
Title: SSL HELP THREAD!!!
Post by: gyraf on July 09, 2004, 11:43:48 AM
1Amp is enough for two, but I wouldn't recommend this. Take care how you do your grounding anyway..

Yes, the timing is the same - but not for the auto release where you used a different cap (as you mention earlier.
Title: SSL HELP THREAD!!!
Post by: Svart on July 09, 2004, 05:33:18 PM
thanks gyraf, you're extremely helpful as always!

cheers!
Title: SSL HELP THREAD!!!
Post by: pxpx83 on July 12, 2004, 04:04:25 PM
I just started stuffing  my ssl pcbs and I've got a question about a couple resistors.  Why is there a * next to the 1k resistors in the left and right VCA?  I did a search, but couldn't find any info.  I am using the dbx 2151, so should I just solder in a regular 1k resistor?

Thanks!
Title: SSL HELP THREAD!!!
Post by: Svart on July 12, 2004, 05:53:29 PM
I don't know but i stuffed them anyway and it works fine..  :thumb:

also I ordered my par-metal cases this week.  should have everything installed by weekend, however I have some little goodies that i might try to include.  maybe some pictures to show later too.  now, the meter..  is that .1A to the highest or is it like a 1A with .1 resolution?

thanks
Title: SSL HELP THREAD!!!
Post by: Greg on July 12, 2004, 06:48:11 PM
Quote from: "pxpx83"
I just started stuffing  my ssl pcbs and I've got a question about a couple resistors.  Why is there a * next to the 1k resistors in the left and right VCA?  I did a search, but couldn't find any info.  I am using the dbx 2151, so should I just solder in a regular 1k resistor?

Thanks!



Yes, 1k is suppossed to be there. I think I remember Gyraf saying that he put that there as a reminder to himself for something. The previous statement might be incorrent... regardless, a normal 1k goes in the 1k* in the left and right channel VCAs.
Title: SSL HELP THREAD!!!
Post by: gyraf on July 13, 2004, 05:03:31 AM
Quote from: "Svart"
 now, the meter..  is that .1A to the highest or is it like a 1A with .1 resolution?


1mA FSD means a meter that takes 1mA for Full-Scale Deflection.

That is, throw in 1mA DC, and the meter shows it's max.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Svart on July 13, 2004, 07:32:38 AM
gotcha.  thanks again gyraf!
Title: SSL HELP THREAD!!!
Post by: on July 13, 2004, 07:57:48 PM
Hi,

I've got a stuffed board. When I apply a signal to the input. I get signal through the circuit until the VCA input...but there does not seem to be any signal at the VCA output...

I'm using the 2180 VCA. I do not have the trimmer installed on the board, I just left that section blank. Is this ok? If yes,

What kind of range of voltages should I be seeing on the control pins and sym pin (pins 2-4) of the VCA.



Thanks in advance,
jason
Title: SSL HELP THREAD!!!
Post by: gyraf on July 14, 2004, 06:13:56 AM
Hi Amekable,

Welcome to "The Lab"!

When using the trimmerless 2180, simply leave out the trimmers (and possibly the two 1M resistors between trimmer and VCA)

If you have signal at the VCA input pin, there surely is a problem, because this is a current-input (like the inverting input in a fed-back opamp) and should act like a virtual ground to your incoming signal.

- Check that you have proper supply voltages +/- 12 and +/- 15VDC

- Check VCA orientation (!)

- Check resistor values around VCA's

Your control voltages (at no signal) should be around 0V at the two outputs of the TL072 (pin1 and 7), with a DC offset added when either "threshold" or "makeup gain" is operated.


Jakob E.
Title: SSL HELP THREAD!!!
Post by: lictme on July 22, 2004, 11:43:14 PM
hmmm...If you build an ssl with the 215x circuit in lieu of the 202, can you insert a 202 over the 215x circuit (assuming you pull the 215x and 5532 out of the circuit)?

-james
Title: SSL HELP THREAD!!!
Post by: Svart on July 23, 2004, 08:19:58 AM
anybody remember where the link to the print-out of the replacement scale for edgewise meters went to?  I can't find it!
Title: SSL HELP THREAD!!!
Post by: JayDee on July 24, 2004, 01:31:13 PM
do you mean this one here:?

http://www.nrgrecording.de/html/vumeter.html

Its from Franks DIY page.
Title: XLR connections
Post by: keithcamilleri on July 28, 2004, 03:41:32 AM
Hi guys,

I just finished stuffing the clone's pcb and I now I have to connect the xlrs, I know it's in a thread somewhere I just can't find it.. can anyone please help me out?

by the way I checked my rails and the 12v seems to bo ok. 15v are giving me 14.57v, 14.94v.. is the 14.57 anything to worry about?

thanks for all your help guys...
Title: SSL HELP THREAD!!!
Post by: Michael Krusch on July 28, 2004, 04:29:02 AM
Absolute voltage is not so important, it's more important to have booth (+&-)  at the same level.
Title: SSL HELP THREAD!!!
Post by: gyraf on July 28, 2004, 04:53:46 AM
Keith,

Voltage should be within 5-10% depending on your regulators, so your figures looks right.

Connecting the xlr's shouldn't be a problem?

Look at the component side layout in the .pdf - it says clearly what pins are left, right, in, out, +, and - on the input and output connectors.

- Simply connect ground (0V) to all pin1's
- Connect "+" to pin2 at appropiate xlr's
- Connect "-" to pin3 at appropiate xlr's

Jakob E.
Title: SSL HELP THREAD!!!
Post by: on July 28, 2004, 11:35:56 AM
I would be interested in that scale as well. That link from jaydee is for the regular meters. I know it's around here somewhere, because i've seen a few completed ssl's with the edgemeters. Anyone have it?

Thanks,
Brandon
Title: SSL Tested
Post by: keithcamilleri on July 29, 2004, 02:18:17 AM
Hi guys,

I tested the clone it works perfectly... it is really transperent on the sound...it's just what I needed... thanks to jakob and to all you guys for the help...

now I am going to try to put it in the case...since I don't have the proper tools it's gonna be a hard time... any suggestions how to cut steel ( next time it will be aluminium thats for sure...)

cheers
Title: SSL Board Questions
Post by: paxworth on July 29, 2004, 02:00:41 PM
What does the * on the gyraf board mean?  Sometimes it is even labeled **.  And example is (1k*).  And, is there only one bridge on the board?Also, how long do the lead wires that connect the 2 boards have to be?  

Thanks for your help,

-jay
Title: SSL HELP THREAD!!!
Post by: gyraf on July 30, 2004, 05:11:04 AM
Jay,

Ignore the *'s on the SSL board, as noted somewhere earlier in this thread. Those are only for my own reference.

There is much more than one wire link on the main pcb - more like 15-20.'


Jakob E.
Title: SSL HELP THREAD!!!
Post by: JayDee on July 30, 2004, 05:31:00 AM
but the 2k labled ** is for the meter sesitivity.

wires should be always short but here they contain control voltage only.

use only one bridge in the pcb!! chosse between onboard and external x-former.
Title: SSL HELP THREAD!!!
Post by: gyraf on July 30, 2004, 05:41:14 AM
Aah.. You ment diode bridge, not pcb wire bridge..  :grin:
Title: SSL HELP THREAD!!!
Post by: pxpx83 on August 05, 2004, 04:27:46 PM
I'm nearly finished with my ssl clone, but I've got a couple questions about some parts.

I'm using a lighted pushbutton switch for my bypass button.  How would I wire this switch? (mouser part: 653-A165L-AGA-24D-2).  I would like to wire it so that the makeup gain is only when the compressor is in.

When looking at my dbx 2151s, is the little circle mark on the vca showing me where pin 1 is?

Thanks!
Title: SSL HELP THREAD!!!
Post by: bluebird on August 06, 2004, 05:14:56 AM
I'm having problems with my SSL...

it seems to work properly over all except for three things:

one side is quieter than the other.
there is a hum that lessens in bypass mode but is still there.
and there is an over all high roll off.

I've checked all my resistors. have all jumpers in place, am grounded from one point which is off the input jack ground. Voltages seem to be all right.

Any Ideas?
Title: SSL HELP THREAD!!!
Post by: pxpx83 on August 07, 2004, 09:31:14 PM
So here is what my bypass switch looks like:

http://img.photobucket.com/albums/v297/pxpx83/switch.jpg

The lettering on the switch from top to bottom is NC  NO  C.   I need to put a jumper on the control board to get rid of makeup gain when the compressor is out, but how do I wire to the switch from the board?

Thanks!
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on August 07, 2004, 09:52:09 PM
If you put the jumper on the board, the makeup gain will ALWAYS be active. With that switch you need to use some sort of relay to break the connection to the makeup gain (where the jumper goes) when you are bypassed.

One half of the switch will control the switch LED

One half will control the bypass function (grounding part of the sidechain)

A relay (driven by the same voltage used for the LED, controlled by the same portion of the switch that controls the LED) will break the connection to the makeup gain.

I wish I could draw up a schematic! I will give it a try here.

Ian

EDIT: Does anyone know of a good (free) schematic capture program that will export to GIF?? I use PCB elegence to design my boards, but it does not export to GIF! I've tried taking screen shots, but they turn out crappy.
Title: SSL HELP THREAD!!!
Post by: bluebird on August 09, 2004, 04:04:26 AM
Just putting this out there again....

I've fixed the high roll off problem with my SSL.

I still have a hum.
Re reading this whole thread I've noticed I have the same exact problem Nele had. less hum with the unit in bypass. and the hum gets louder when turning up the make up gain pot

I think it has to do with the switching panel. if I put my finger by where the bypass switch wires go to the PCB  the hum gets louder.

Its weird because everything works perfectly. So what gives? Could I have wired something wrong with the bypass and have it still work perfectly?
Title: SSL HELP THREAD!!!
Post by: tubejay on August 11, 2004, 05:37:34 PM
Okay, so I fired up my GSSL today, and it works...SORT OF!  Hopefully you wonderful people here can help me.  Here's the situation:

It passes signal equally on both channels, and sounds normal.  The makeup gain knob works perfectly.  My problem, NO COMPRESSION!  Well...sort of anyway.

I think the problem is in my bypass switch.  If I put my fingers on certain pins, while putting my fingers on the pins with the two outer switch wires on them, it will do a super compression, almost as though I had the threshold WAY WAY down.  So I cut the wires to the two outer pins of the connector and tried just connecting them to the center wire on the knob.  Then I got an infinite compression, meaning no sound.  It attacks, releases, and sounds like the ratio is correct.  It seems weird, and the threshold control just seems to have no effect on the signal, regardless of my fingers touching etc.  I guess the problem could be there too.  

Any ideas?

Thanks,

Jay
Title: SSL HELP THREAD!!!
Post by: tubejay on August 12, 2004, 09:18:05 AM
Anyone?  If I need to supply more info, please let me know.  I don't see any lifted traces etc...
Title: SSL HELP THREAD!!!
Post by: gyraf on August 12, 2004, 09:39:52 AM
Try tracing the DC CV voltages through the sidechain rectifier, the timing, to the ½TL072 that also carries makeup gain, and the other½ that carries threshold..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tubejay on August 12, 2004, 03:42:41 PM
Thanks for the help Jakob!  You'll have to excuse me, most of this is new to me, so I may not understand everything you're telling me.  Unfotunately I'm not sure I understand how to trace the DC CV voltage.  I don't understand where to get that??  Which pins on the 072 should I be looking at?  

If this helps, I'm getting +12 on wiper one of the threshold pot, and variable voltage at the middle pot (depending on where I turn it) and -12 on the last wiper.  

When the compressor is not bypassed (ie the com and on holes on the pcb are jumpered) the meter needle slams all the way to the right, showing infinite compression.  Also, I can FAINTLY hear sound when it's jumpered, and turning the makup gain all the way up turns it up a little more, though it's still REALLY quiet.  I checked all of my resistors and all of the solder points around the 072, and all looks good, with no touching traces.  

On the 072 here's the voltages I'm getting when not bypassed:

Pin 1 - 6v (actually variable depending on where I have the threshold from 6v to 0v)

Pin 2 - 0v
Pin 3 - 0v
Pin 4 - -12v
Pin 5 - 0v
Pin 6 - 0v
Pin 7 - 5v
Pin 8 - 12v

Thanks again for your help, I'm pretty lost here!!
Title: SSL HELP THREAD!!!
Post by: gyraf on August 13, 2004, 05:11:33 AM
Jay,

- At point "C" (going to the control board) you should have a DC voltage that is zero for no input signal, and going gradually more and more negative with higher input levels. When the unit is working properly, the threshold pot will also vary the negative voltage here (when there is input signal present)

- This DC signal should also be present at point "D" (providing that the unit is "IN", not bypassed) - now the DC voltage's A/R timing has been set by the A/R switches.

- An exact replica of this signal should now be present at pin8 of the TL074 - this is the DC voltage driving the meter through the 2K resistor.

- This DC signal is added to the voltage dialed in with the threshold and makeup gain pots, and is found at pins 1 and 7 on the TL072

Double-check orientation of your diodes, specially the one at point "C" ...also check that all your IC's are getting the right supply voltages, and that none of them run hot

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tubejay on August 13, 2004, 03:12:20 PM
Thanks Jakob, well I think we're getting closer.

At pin C I am constantly getting -10v, no matter what.  At point D I get -10v when not bypassed, and 0v when bypassed.  

I checked all of the diodes and they are in correctly.  I also checked them with my diode checker and they all measure 667, whatever that means.  I assume that means that they are operating normally.

It looks like whatever the problem is, is related to this.  As always, your help is most appreciated!!

Thanks,

Jay
Title: SSL HELP THREAD!!!
Post by: on August 13, 2004, 05:09:19 PM
stupid question....


how do the attack, ratio, and release switches mount on the pcb. It seems they could fit a couple ways. Do the numbers on the back (1-12) mean something?

Thanks,
Brandon
Title: SSL HELP THREAD!!!
Post by: Aharon on August 13, 2004, 05:37:56 PM
Yes,the #s mean something.Check also the letters,A,B,C,D  in the center and compare to the layout.
Aharon
Title: SSL HELP THREAD!!!
Post by: Jonathan Hayward on August 13, 2004, 06:29:32 PM
Frist, the numbers on the back indicate the number of ways the switch can be made to go. For each switch, check the number of ways it needs to go on the schematic (for example the ratio goes 3 ways) and then put the little washer with the perpendicular spike on it with the spike in the hole by the number three on the switch's body (and make sure it stays there until you've fixed the switch board to the frontpanel).
Title: SSL HELP THREAD!!!
Post by: tubejay on August 13, 2004, 09:11:00 PM
Does it matter which direction they go in?  For instance, there's two potential ways each switch could go in (on Gustav's PCB's, which is Gyraf's 7th rev).  My understanding was that it doesn't make a difference which way you put them in.  However, that might be why I can't get mine to work properly!   :wink:
Title: SSL HELP THREAD!!!
Post by: tubejay on August 13, 2004, 09:14:33 PM
Quote from: "tubejay"
Thanks Jakob, well I think we're getting closer.

At pin C I am constantly getting -10v, no matter what.  At point D I get -10v when not bypassed, and 0v when bypassed.  

I checked all of the diodes and they are in correctly.  I also checked them with my diode checker and they all measure 667, whatever that means.  I assume that means that they are operating normally.

It looks like whatever the problem is, is related to this.  As always, your help is most appreciated!!

Thanks,

Jay


Also, to add to this, the threshold control has no impact on the voltage present and point C or D.  C is always -10v and D is either -10v when engaged, or 0v when bypassed.  Something must be shorted??  Is there a trick to mounting the switches that I'm screwing up possibly??
Title: SSL HELP THREAD!!!
Post by: gyraf on August 14, 2004, 05:01:23 AM
The switches are symmetrical, so it dosen't matter what way they are mounted. Only you need to adjust the "end-stop" for the release switch to five positions.

Jay - If you have constant -10V at point "C", then your problem probably is in the rectifier section or in the ratio switching.

- First lift the two wires at points "A" and "B" and see if the -10V goes away (with no input signal). If so, then there's a short or a wrong resistor value around the ratio switch.

- If that dosen't do it, then check for shorts and correct components at the rectifier around TL074 pins 1-2-3 and 12-13-14. Possibly exchange the TL074 for a new one. Check orientation of ALL diodes. Measure DC voltage at TL074 pins 1, 2, 13, 14.

- make sure that your sidechain VCA is orientated the right way around. It is mounted opposite of the two audio VCA's!

Jakob E.
Title: SSL HELP THREAD!!!
Post by: HappyTom on August 14, 2004, 06:56:29 AM
I'm getting done with my clone just one thing missing.. Juice for the light in the behringermeter (BE-46). Anyone knows where to get that? I know it's been up in a thread somewhere but i can't find it.
Title: SSL HELP THREAD!!!
Post by: tubejay on August 14, 2004, 09:45:48 AM
OH - MY - LORD!!!!  I can't believe it, I had the sidechain VCA in the WRONG WAY!!!  DOH!!  I had read not to do that, probably in 10 different places, and somehow I still managed to screw it up!

Jakob, as Bette Midler would say, "did you ever know that you're my HEEEEE-ROOOOOOO??"  Thank you so much for your help, hopefully if someone else has this problem I can help them out.  I can't say it enough, THANK YOU THANK YOU THANK YOU!!

DIY SUCCESS!!!  I ran a drum machine through it this morning, and it sounded very nice indeed!  I have a mix session next week, and I can't wait to try it out!  I'll post results.

Now, I'm with HappyTom, I need to get that light going in the Behringer meter.  Has anyone done this?

Thanks again Jakob, your patience is truly a virtue!


 :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :guinness:  :thumb:  :thumb:  :thumb:  :thumb:  :thumb:  :thumb:  :thumb:  :guinness:  :guinness:
Title: SSL HELP THREAD!!!
Post by: Jonathan Hayward on August 14, 2004, 09:50:29 AM
Tom What's the voltage rating on the Behringers.

Over-keen boy here popped his Chips into the board last night (having care fully checked the supply voltages). Inserted the two 5534s in the vca circuits round the wrong way; much heat in the 2181s and now massive distortion with new 5534s in the right way. No compression either (but the sidechain and meter are behaving correctly).

I'm assuming the 2181s are cooked, does this tally with anyone's experience?
Title: SSL HELP THREAD!!!
Post by: tubejay on August 14, 2004, 10:49:51 AM
Jonathan, is it distorted even when it's bypassed?  I'm not sure if the channel VCA's are bypassed when the unit is in bypass, but I don't think they are.

The sidechain might be the only thing being bypassed then.  In that case, the unit will still operate in bypass if there's no 2181 in the sidechain vca slot.  If that's the case, you could take the 2181 out of your sidechain and put it in one of the channels to see if it's the 2181's that are fried, or the 5534's.  If it's still distorted with the sidechain 2181 moved to one of the distorted channels, it's either the 5534's or something else.

I'm not certain this is all correct, but from my experience with having the vca in the sidechain in backwards, this is how I expect bypass works.  It would at least allow you to check and see if it's the 5534's or the 2181's.

Jakob, let me know if I'm wrong here.
Title: SSL HELP THREAD!!!
Post by: gyraf on August 14, 2004, 10:56:22 AM
Jay,

Good that you got that fixed!  :guinness:


Jonathan,

Audio passes the VCA's even when bypassed. The bypass simply cuts of the sidechain signal path (right before the timing circuit)

To check if it's your audio VCA's that are fried, try substituting one of them with the one from sidechain (if you're sure there's no other component problems now) Note orientation!  :razz:

The unit will pass signal with no sidechain VCA, but will not compress. So at least you should be able to check if your VCA's are allright.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: on August 14, 2004, 05:08:42 PM
I'm looking to have two buttons with LED's for the power and bypass. There is one take-off for an LED on the control pcb, can I come off that same spot for both LED's?

Thanks,
Brandon
Title: SSL HELP THREAD!!!
Post by: gyraf on August 15, 2004, 07:58:50 AM
Brandon,

You could, but it's preferable to use individual dropper resistors for each LED. Just tap off the +12V on the control board where the LED dropper resistor already sits...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: HappyTom on August 15, 2004, 09:33:49 AM
Quote from: "Jonathan Hayward"
Tom What's the voltage rating on the Behringers.


I found a thread where Greg powered up his meterlight with 12 VDC but i can't find if he found out where to get the power for it in the clone.

HT
Title: SSL HELP THREAD!!!
Post by: Jonathan Hayward on August 15, 2004, 09:42:10 AM
Any point at 12V DC should do on the circuit, it should have current to spare for a small bulb. There may even be a spare 'hole' available at that voltage you could attach the wire to (other side of the bulb to ground), if not, just solder the wire to the solder side of the pcb.
Title: SSL HELP THREAD!!!
Post by: gyraf on August 15, 2004, 09:56:32 AM
Please do NOT use the 12V rails form the SSL-clone PCB for meter light, as there is not enough current for that - we're stabilizing the 12V's with 78L12/79L12's. Also, the 12V's are used for reference and we don't want any dirt in there...

For meter light it would be better to use unregulated supply voltage with an appropiate voltage dropping resistor (use Ohm's law..)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Jonathan Hayward on August 15, 2004, 03:20:00 PM
well that told me didn't it! :oops:
Title: SSL HELP THREAD!!!
Post by: Svart on August 15, 2004, 11:14:05 PM
I mounted a separate Vreg off the board especially for my meter and power lights.   make sure you isolate it and ground it at the star.
Title: problem with my 2nd ssl clone
Post by: ChrisA on August 20, 2004, 08:41:57 PM
I just built a 2nd ssl clone and went to power it up and immediately the LM7915 got way too hot...the unit does not appear to pass any audio either...so I shut it down.

Everything looks ok, but I'm going to check to see if there are any solder bridges on the pcb.

has anyone had this problem?

thanks guys

chris
Title: SSL HELP THREAD!!!
Post by: JayDee on August 21, 2004, 10:40:24 AM
Just as an additional info for the SSLs "hanging up" during power on. In my clone it wasn´t only the 78L12 and 79L12. I also had to change the 7815. I think there are bad production series out there. After changing the 7815 I never had the power on hang up problem.

cheers
Jürgen
Title: SSL HELP THREAD!!!
Post by: pxpx83 on August 22, 2004, 05:44:07 PM
So I've been staring at my nearly finished ssl for a couple weeks now and I think it is finally time to finish it (now that the electricity has been turned back on after the hurricane).  I'm not sure how to wire my bypass switch and relay.  I want to defeat makeup gain when the compressor is bypassed.  Here is a quick drawing I did of the layout:

http://img.photobucket.com/albums/v297/pxpx83/ssllayout.gif

Any help would be appreciated.


Thanks!
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on August 22, 2004, 07:51:14 PM
Ok, sorry in advance for the horrible drawing! I just used paint to connect the dots. You will want to double check my work before you solder everything up!! The jmp is a jumper where the 1k current limit resistor for the power on led is. I jumper it so I can use individual current limit resistors for the LEDs. Hope this helps!!!

(http://www.uweb.ucsb.edu/~imacgreg/PXPX83_SSL.gif)

Ian
Title: SSL HELP THREAD!!!
Post by: pxpx83 on August 22, 2004, 09:11:02 PM
dude...  you rock!   I'll solder everything up and let you guys know the results.

Thanks!!
Title: SSL HELP THREAD!!!
Post by: ChuckD on August 22, 2004, 09:23:27 PM
Where did my + rail go????

I had everything up and running but then all of a sudden I only see 3.3 VDC on the inputs of both 7815 and the 78L12.
This results in the +12 rail becoming 1.5 VDC instead.

Did I blow the diode bridge ? Is that possible?
Maybe one of hose big caps is screwy?


any ideas?  

-Chuck
Title: SSL HELP THREAD!!!
Post by: gyraf on August 23, 2004, 04:36:32 AM
Chuck,

- Check the bridge rectifier with the diode tester on your voltmeter.
- Check AC supply lines coming to the bridge rectifier.
- Check DC at the output of bridge.

- To check for possible shorted supply lines, cut the pcb trace going from the voltage regulator and measure voltage. Remember to repair the cut afterwards :-)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: daniel_c on August 23, 2004, 08:33:48 AM
Hi guys ,

I've just about finished my G4000.  All I need to take care of is the power and I have a couple of questions.  

Im looking at getting a toroidal tranformer.  (farnell 430-1389)  Is a 30VA transformer over kill or should I get a 15VA?

Also , I want to double check the wiring of the transformer.  Its a dual 115v primary , dual 15v secondary type.  

Primary 1 has a blue wire and a grey wire , primary 2 has a violet wire and a brown wire.  (there is a black dot next to the blue and the violet , that shows the start of the winding , right?)

Secondary 1 has a black and a red wire , secondary 2 has a orange and yello wire.  (with dots next to the black and orange wires).
We are 240V here in Australia , so should I connect the blue wire to the active treminal , join the grey and violet wires , and connect the brown wire to neutral.

As for the secondary , should I join the red and orange wires and connect them to the centre of the PCB power in , and the black and yellow wires go to the 2 outside holes of the PCB power in?

One more thing.... as far as a fuse goes , would 100ma be enough or is it more like 1A?

Sorry for so many questions.

Thanks  

Dan
Title: SSL HELP THREAD!!!
Post by: Svart on August 23, 2004, 09:29:02 AM
from what you said, you have the correct idea on the primary and secondary wiring(both are in series).  15va is what i use and it's fine!  

I would go with a 1 amp fuse.  I put some lights in mine and it pulls about 1/4 amp.

and ask as many questions as you need! that's what this place is for!

good luck!
 :thumb:
Title: SSL HELP THREAD!!!
Post by: ChuckD on August 23, 2004, 07:09:27 PM
Thanks Jakob,

I put the diode mode on and looked at the rectifier and it seems ok!
I then left it in that mode and looked across the Voltaghe regulators. the results was puzzling, it indicated a short.

To confirm this I put the multimeter in Resistance mode and looked at the outputs on each voltage regulator to ground the 7915 gave 15-16Kohms while the 7815 gave 1.5 ohms.
This confirms that there is a short somewhere after the 7815 I believe.

I gonna try to find it.
Does that sound like the problem to you guys?

-Chuck
Title: SSL HELP THREAD!!!
Post by: on August 23, 2004, 10:30:26 PM
Gyraf,
can you please elaborate on the power and bypass led positions. I have the power led powered off the 1k resistor where it's supposed to go. Since +12v is coming from the top of that, what is the voltage after that resistor? I'm trying to find a 12V led and I'm beginning to realize that that's kind of hard, so I'm assuming there's some kind of voltage drop over that resistor. I know V=IR, but how would that be applied. I assume the other LED that I'd like to add for the bypass switch will just come off the +12V with a 1k resistor added like the other take off for the power LED.

Thanks,
Brandon
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on August 23, 2004, 10:57:45 PM
Brandon,
     Most LEDs will only drop 0.5-0.8V. You must use a current limit resistor in series to drop the rest of the voltage. Using P = IV and V = IR to make sure that the resistor is the correct wattage. For example, if you want to power a LED (assume 0.7V drop) from 12V, you need a resistor to drop the "extra" 11.3V. Say you use a 1k resistor. There for the LED will get 11.3mA current. Since P = I^2*R, the resistor dissapates around 128mW, which is well under the 250mW limit for 1/4 watt resistors.

Ian
Title: SSL HELP THREAD!!!
Post by: on August 23, 2004, 11:23:13 PM
So I guess I don't need to look for a specific type of LED or anything then? So why are LED's specified as 3v, 6v, and 12v at radio shack if they all just only drop 0.7V?

Brandon
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on August 24, 2004, 02:35:36 AM
Hmmm... are you sure these are not lamps? Maybe they have an internal dropping resistor?? Do you have a link for these parts??

Ian
Title: SSL HELP THREAD!!!
Post by: gyraf on August 24, 2004, 04:56:45 AM
Yep, as Ian says, use a standard LED, the voltage dropping / current limiting is taken care of by the onboard 1K resistor.

Yes, you can get LED's with internal resistor for certain voltages, but we use the plain no-resistor type here.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on August 24, 2004, 09:45:00 AM
Often times the LED's spec sheet will specify what value of current limiting resistor to use depending on the rail. I remember the one I used said to use a 1k with a 12V rail, and I think that's what is actually on Jakob's board. I always like to give the spec sheet a glance to make sure.
Title: SSL HELP THREAD!!!
Post by: on August 24, 2004, 04:45:20 PM
sounds good. I think most just have a max voltage. Something like 3.5 v @20mA.

I thought I post this for any interested. I found a site that'll send you samples of products. LED's specifically if you only needed a few. They have quite a selection.

http://www.marktechopto.com

Brandon
Title: SSL HELP THREAD!!!
Post by: kvintus on August 30, 2004, 12:13:08 PM
Did we find any solution to the hum problem? I've just finished a GSSL clone that works good but I have a 50Hz hum at -73 dBu in the right channel and -66 dBu in the left channel. Any ideas?

/Anders
Title: SSL HELP THREAD!!!
Post by: gyraf on August 30, 2004, 12:17:25 PM
I've never had ANY hum above noise level in any of the units I've made..

Check that your +/-15V supply voltage is clean. Too low voltage from the transformer can be a problem.

Redo your grounding - it may be a ground thing.

Check that it actually IS the clone that is humming - measure outputs with shorted inputs.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: kvintus on August 30, 2004, 12:59:15 PM
My supply voltages do not hum. They have some HF noise at about 5 mV but no hum as far as I can see. I use the 2x18V PCB transformer from farnell that you suggestet (the blue one) and the secondary voltages are ok.

How should the grounding be done, anyway? I know it's a stupid question, and I know how grounding is done (I think), but could you please go through it once more just in case I've missed anything.

Thank you for your help, Jakob!

/Anders
Title: SSL HELP THREAD!!!
Post by: gyraf on August 30, 2004, 01:09:47 PM
First of all, connect input ground (at the input pcb connector) to chassis at one of the input XLR's. And ONLY connect 0V to chassis here.

If you draw current to a meter light, try disconnecting this.

Does your hum change with makeup gain?

Is your unit boxed or just a PCB on your desk?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: kvintus on August 30, 2004, 01:15:11 PM
Quote
First of all, connect input ground (at the input pcb connector) to chassis at one of the input XLR's. And ONLY connect 0V to chassis here.


Done that. Still humming.

Quote
If you draw current to a meter light, try disconnecting this.


No lights connected.

Quote
Does your hum change with makeup gain?

Yes. I get -66dBu without makeup gain (or bypass).

Quote
Is your unit boxed or just a PCB on your desk?

Sheetmetal box.

/Anders
Title: SSL HELP THREAD!!!
Post by: kvintus on August 30, 2004, 01:50:51 PM
By the way, I use plastic connectors and the inside of the box is painted with non-conductive paint. I also use plastic washers for the pcb spacers. So there is not any connection to ground except for a wire that goes from input pin 1 to a ground screw in the chassis. Input pin 1 connects to the pcb.

/Anders
Title: SSL HELP THREAD!!!
Post by: kvintus on September 01, 2004, 06:23:15 AM
Bump...

Still hunting for hum. Could this be anything else than grounding? I have tried to redo the grounding in several different ways but it doesn't change. Can someone tell me what to look for?

Thank you!

/Anders
Title: 2181 in parallel
Post by: keithcamilleri on September 03, 2004, 08:11:57 AM
Hi jakob,

Just wanted to ask whether I need to change the voltages if I try to use 4 x  2181 in parlallel for every channel?

Would it make any difference if I use 2180 instead of 2181s?

Just read that 4 vca in parallel would make the sound better? any truth in that?

Sorry for all the questions

Keith
Title: SSL HELP THREAD!!!
Post by: radiance on September 03, 2004, 11:20:59 AM
@ Kvintus: I got rid of a lot of hum (well not really a lot but some) by turning my toroid transformer 90º.
Title: strange behaviour
Post by: andre tchmil on September 04, 2004, 07:26:16 PM
from time to time when I switch the ssl on, the meter goes full scale to the right and if I remember well , the unit doesn't pass audio.
power off and on again solves the prob.
Any idea what causes this ?
Other than that the clone is really working and sounds great.
Title: SSL HELP THREAD!!!
Post by: gyraf on September 06, 2004, 04:21:35 AM
Andre,

You probably have a 7815 or a 78L12 latching up. Try to provoke the error by turning on and off some times (allow unit to discharge completely between tries). Once you have the error, measure the +/-15V and +/-12V lines. One of them is probably not working.

There is an issue with certain brands of (specially positive) regulators. Change the bad one to a different brand.

Keith,

I don't think there's much to be gained by paralleling more VCA's. The 2180 is spec'ed better than the original 202C.

Anders,

Try taking your power transformer out of the box to see if it is induced hum, or poser line hum. If physically removing the power transformer helps, try moving it around inside the box to find the location with least hum. If removing the transformer dosen't change anything, try measuring your +/-15V lines for ripple. Does the hum change when you short the inputs?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: andre tchmil on September 06, 2004, 05:40:39 AM
Thanks Jakob.
Will try that.
Title: SSL HELP THREAD!!!
Post by: gyraf on September 06, 2004, 05:58:25 AM
Andre,

Here's a thread about the problem:

http://www.groupdiy.com/index.php?topic=440

Jakob E.
Title: Distoration on my SSL......
Post by: edgedaniel on September 06, 2004, 08:26:33 AM
Hi!

I have som troubel with my SSL!

When i set the Release at 0 it sounds perfect. But when i increase the release time it started to crackle more and more. At the Auto posision its worst.

Do anyone hava any idea of where i should start checking.

Could it be the input that is too high?

Is the SSL working with +4dBv och -10dBu as input?
Title: SSL HELP THREAD!!!
Post by: gyraf on September 06, 2004, 08:29:13 AM
Make sure that the wire links on the control PCB are in place.

One of the wire links is often overlooked when assembling (there may be something about this earlier in this thread..)

Jakob E.
Title: 1 Meter on 2 SSL
Post by: keithcamilleri on September 17, 2004, 02:41:52 AM
Hi Jakob,

I am building 2 ssl in one case and I would like to use 1 meter. Would I be doing anything wrong if I'll put a switch and this switch will be used to switch from one compressor to the other.

So that when the switch is on one position I'll be viewing the meter of one compressor and when the switch is on the other I'll be viewing the second compressor...


cheers
Title: SSL HELP THREAD!!!
Post by: gyraf on September 17, 2004, 02:48:07 AM
Keith,

That should work. But why not two meters?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Kev on September 17, 2004, 02:49:17 AM
One of mine has a switch on the meter for a change in sensitivity and also includes an OFF position.

I don't see any problem with leaving the meter drive circuit ... open.

Keith,
where are you from ??
camilleri  ....  is a name known around these parts ....   :cool:
Title: Meter
Post by: keithcamilleri on September 17, 2004, 03:23:46 AM
Hi Kev,

I'm from Malta man... Loads of maltese in the 50s just went to Australia looking for jobs...   :grin:

you're probably from sydney then ? or not?

thanks for your help kev ... I appreciate a lot
Title: Re: Meter
Post by: Kev on September 17, 2004, 03:30:11 AM
Quote from: "keithcamilleri"
I'm from Malta man...


Of course you are ...  :green:

Here in Melbourne we have Joe Camilleri and some of his family
... and a few of my work mates come from Malta.
They make a lot of noise BUT we still love them dearly.  :wink:
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on September 17, 2004, 04:59:55 AM
maltese are all noisy man :green: we were designed with a faulty gate/limiter...

I would love to visit there...we could meet up.. it's one thing I have to do to come to Australia...
Title: SSL HELP THREAD!!!
Post by: funkysam on September 17, 2004, 05:31:01 AM
Hi all!
I've just created an account here as I surfed on this forum for quite a few months now :wink:
I also want to build this SSL clone, as I need a few bus comps for my project studio.
I'm building my shopping list while reading here the posts concerning this project, and I have a question concerning the transformer, because I've read quite a few posts concerning hum and so on...
I don't really know what trafo to buy. I could buy the one that fits on the PCB (the blue farnell one), because it simplifies the building step a bit, but is this not better soundwise to use a toroid one?
Thanks all for your time,
Sam.
Title: Toroid
Post by: keithcamilleri on September 17, 2004, 05:34:48 AM
hi funkysam welcome...

I have used a toroid in my first ssl...all went fine regarding humming...if you follow kev's list you should be ok...
Title: SSL HELP THREAD!!!
Post by: gyraf on September 17, 2004, 05:52:02 AM
Hi Sam,

Welcome to "the Lab"!

The powersupply transformer for the SSL-project is not very critical. But if you want to play it safe, just use a 2x15V, 500mA or larger, toriod transformer.

Good luck with the project!

Jakob E.
Title: SSL HELP THREAD!!!
Post by: funkysam on September 17, 2004, 06:25:00 AM
Thanks You Guys for your answers!
I think I'll go for a toroid one if I can find one that can fit in a 1U rack.

Jakob, you said 500mA or less but the blue farnell one that fits on the pcb delivers only 130mA per secondary, so I guess 130 mA is the minimum recommended for a secondary.

Yes Keith, I try to "stick" as much as possible at Jakob's list, to avoid any surprises.

I will just make 2 "mods" (if we can call that a mod... :oops: ):
- use a DPDT switch for bypass (with makeup gain off when bypassed) insted of the rotary switch

The other one, I don't know, but I think I won't add a VU meter. Do you all really use them? 'cause I guess they're not that accurate...
Title: SSL HELP THREAD!!!
Post by: gyraf on September 17, 2004, 09:12:27 AM
Yep, 130mA/sec is it's basic needs. But for e.g. light for the meter, you'll need a bit more..

Jakob E.
Title: Re: 1 Meter on 2 SSL
Post by: lictme on September 17, 2004, 11:17:01 AM
Quote from: "keithcamilleri"
Hi Jakob,

I am building 2 ssl in one case and I would like to use 1 meter. Would I be doing anything wrong if I'll put a switch and this switch will be used to switch from one compressor to the other.

So that when the switch is on one position I'll be viewing the meter of one compressor and when the switch is on the other I'll be viewing the second compressor...


That's not a problem at all. I did the same thing for what ended up being a quad-channel comp. For me, I did it because I wanted a big meter and didn't have the space for two.

-james
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on September 19, 2004, 06:02:46 AM
thanks lictme ...

doing the same thing too....

which meter did you use?

I am using a 29w sifam...my problem is that I don't know what I am reading... since it's not a vu the printed scales that came with it are not a vu style. so its not straight forware to read...
Title: SSL HELP THREAD!!!
Post by: gyraf on September 19, 2004, 06:08:28 AM
Keith,

The SSL-clone does not use a VU-type meter, but a linear-scale DC-reading meter.

The readout will be dB/linear segment of the scale - reading from bottom to top, not backwards like 1176 and so.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: lictme on September 19, 2004, 12:24:32 PM
Quote from: "keithcamilleri"
thanks lictme ...

doing the same thing too....

which meter did you use?

I am using a 29w sifam...my problem is that I don't know what I am reading... since it's not a vu the printed scales that came with it are not a vu style. so its not straight forware to read...


I used an old simpson meter (1ma) that I found in a surplus yard. There's a meter scale that nrgrecording made for the group that is easily scaled to fit any meter face - use that to replace your sifam scale and the compression display will make a lot more sense (look for it in the ssl meta).

-james
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on September 19, 2004, 01:50:31 PM
thanks james & jakob...  :thumb:
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 10:32:30 AM
Hey guys, here's my problem. My clone seems to function properlly when I send it a low signal. but hot signals turn into the big muff. even in bypass. It also distorts low input signals when I boost moderate makeup gain. This is in all positions of the release switch. the sitch is configured properly. I am using a double pole double throw toggle switch for bypass. Thanks in advance for any help.
Peter
Title: SSL HELP THREAD!!!
Post by: Svart on October 01, 2004, 10:52:18 AM
I assume big muff means that it distorts the high end or cuts it completely?
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 12:43:52 PM
yes it brittle distortion, no high end cut, Just checked all resistor values, looks good, I know thats the most comon error. I'm puzzled. tried switching vcas, with my extras.(I have 2180las)
I wonder.
Peter
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 02:30:43 PM
At low output, it is working properly.(sounds really good.) But turn output to a nominal level, or flip it into bypass, and it gets crunchy. I can turn the levelup at the source, before the compressor, and as soon as it gets to the nominal level, distortion.
Bummer.
Peter
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 02:39:25 PM
probably someting really simple. Anyone have any ideas?
thanks,
Peter
Title: SSL HELP THREAD!!!
Post by: Svart on October 01, 2004, 04:01:24 PM
not sure.  thinking about it though...  have you measured the output of your desk?  how about the output of the unit?  are the i/o balanced or unbalanced?
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 05:12:11 PM
its ballanced. I'm coming strait out of my converters (lavry blues) into a poweramp. do you want me to measure impedance or voltage?
Yhanks for thinking about this.
Peter
Title: SSL HELP THREAD!!!
Post by: Svart on October 01, 2004, 05:15:07 PM
it would be voltage, however you would need a sine wave input to the GSSL.
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 05:32:37 PM
ok, I used a synth to get as pure a sine wave as i could, an my converters are outputting  136mV, and the clone is putting out .18 volts
Peter
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 06:06:09 PM
I'm ging to try the unity gain mod. I'llsee how that changes things.
Title: SSL HELP THREAD!!!
Post by: mesmer on October 01, 2004, 06:58:36 PM
OK, that was it. This is a hot box. Like 10 dB more than my alan smart c2. The unity gain mod put more in line with the smart. So I'm happening now. Thanks for helping me sus this out. By the way, The sound is great. Its diferent from the smart, but we allready knew that. I've read a lot of people thinking about this project, wondering how close to the original they are going to get. Let me say the smart, that costs $2800 does not sound more expensive.  Thanks diy and the greatest Dane Jakob! Pics soon.
Peter
Title: SSL HELP THREAD!!!
Post by: moogfrotee on October 01, 2004, 07:37:53 PM
Hi everybody,

I´m a new member of this great forum.

here is my first question:
I´ve just finished my GSSL, but I´m not so shure about the
VU-meter that I´ve got , because its reacting kind a strange.
Is it o.k. to use a VU-meter at all or does it have to be
a 1mA-meter and why?

The VU-meter that I´ve got is small but realy cool looking,
so I would like to keep it. Can anybody help me?


Cheers
moogfrotee
Title: OOOPPPSSSS!!!
Post by: keithcamilleri on October 10, 2004, 02:03:36 PM
Hi Jakob and all,

I have stuffed two ssl boards, and I have the same problem in both, the  sound from both is distorted and vey low (and somehow like high passed), the make up gain works fine cause I can hear the sound going up a bit... but as soon as i turn the treshold full anticlockwise a big fat hum comes in.... :sad:

the meter dose nothing but as soom´n as the big hum comes in goes less than 0...

any ideas??

regards ....
Title: SSL HELP THREAD!!!
Post by: gyraf on October 11, 2004, 03:34:21 AM
keith,

Sorry, no idea. As always, check and recheck psu, components and soldering.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: smilinfu on October 11, 2004, 11:27:13 AM
Are you susing the 2180 (or the self baising version whatever number).  If so try disconecting pin 4.  Solved my noise problems.
Title: down to one...
Post by: keithcamilleri on October 11, 2004, 04:38:54 PM
hi jakob and all...

i got it down to two problems...it was a combination of things unbalanced inputs, not earthed, control panel soldered badly (the worst soldering ive ever done actually) etc.... mainboard I think that is working fine...

One problem is when I turn the treshold to the negative side of the pot, I can see a spark in the pot... and the sound goes down....

The other problem is that... the meter is reacting too much to the sound... I am using a 1ma fsd meter with a 2k res...

Can anyone please help me out...

regards...
Title: Re: down to one...
Post by: gyraf on October 12, 2004, 03:21:58 AM
Quote from: "keithcamilleri"
One problem is when I turn the treshold to the negative side of the pot, I can see a spark in the pot..


Does the threshold work as it should otherwise? Check that pot wiper isn't shorted to ground or +12. Check that it's the right series resistance between pot wiper and opamp (see schematic)

Once you get the unit working right, experiment with a trimmer resistor across the meter to dial in the right reading.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on October 12, 2004, 03:36:00 AM
hi jakob,

yep it does work ok ... but when the dial touches the negative contact of the pot i could see a spark there and then the sound goes low .... I checked the voltages and it does give the 12v for the sidechain... maybe I'm missing something...I'll recheck for voltages and for the resistor tonight...

I didn't have these probs with the first clone, maybe it  was beginners luck :-)

Thanks for your reply Jakob appreciated as always...

Regards
Title: SSL HELP THREAD!!!
Post by: j.hall on October 12, 2004, 05:05:32 PM
probably has been covered already but i can't ever seem to get a good search result here.

the schematic shows +/- 15 volts on pin 4 and 7 of the 55332's in the VCA section.  but the PCB layout has a - 15volt trace that goes to another pin (can't remember which one....sorry)

i have two pins on my sockets that show a -15 volt rail and one that has the +15 volt rail.

is this normal, or have i done something wrong.  i don't want to plug my chips in and power it up until i figure this out.

thanks,
j.hall
Title: METER
Post by: keithcamilleri on October 13, 2004, 02:04:57 AM
Hi jakob

all working well now...

Only the meter is not looking right, It is working , for example when the attack or release ares switched the meter does change but when the treshold is set to the highest point the meter goes over FSD.. .. I am Using a SIFAM A29 0-1ma FSD.... Is it something I did or is it working well?

Thanks
Title: SSL HELP THREAD!!!
Post by: gyraf on October 13, 2004, 05:45:41 AM
Hall,

Compare to the PCB layout PDF. That is known working.

Keith,

I don't understand what problem you have? From the description it is working as it should? You shouldn't change timing in the middle of a mix anyway, and the meter will off course go off-scale if you compress more than it can indicate..?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: j.hall on October 13, 2004, 11:23:26 AM
Quote from: "gyraf"
Hall,

Compare to the PCB layout PDF. That is known working.


OK, every thing looks fine on the PCB layout PDF and my actual PCB's and soldering job.

i guess my question is.  should i be getting - 15 volts on two different pins on the 5534's in the VCA section?

accroding to the PCB layout, i should.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 13, 2004, 12:25:57 PM
On the layout I only see -15V going to pin4 on the NE5534 at the audio VCA sections..

What other 5534 pin do you have shorted to pin4?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: j.hall on October 13, 2004, 01:26:16 PM
i'll have to check again.

stand by.............

could i possibly have my polarity flipped?

are there two pins that should have +15 volts?
Title: SSL HELP THREAD!!!
Post by: j.hall on October 13, 2004, 02:35:08 PM
never mind. i was totally looking at the wrong thing.

everything is running just fine.
Title: SSL HELP THREAD!!!
Post by: fum on October 18, 2004, 12:59:11 AM
Allright,

Bench checking my second SSL, and it doesn't presently pass signal at all.  I've checked the DC voltages, and everybody is happy. I've been over the board a couple times looking for shorts, doesn't mean there isn't one there still.

The left channel passes a sine wave, but cranks it on output(whether bypassed or not), and turns it into a saw wave, just about.  Controls do little to nothing.  

As for the right, if I feed it a sine wave on the right channel, I lose the signal coming out the other side of the 22k resistor before pin 2 of the input 5532.

Here's a couple somewhat unrelated questions ( plus filling in details of the parts I'm using).  I'm using 202 VCA's, and THAT 2181LB in the sidechain.

If using 202's, are the trim pots removed?  I've got them in there at present, but thought I'd ask.

My meter was working when I first started testing, and now it is pegged ( and stays pegged).  Ever run into this, and is there a way to "unpeg" it?

Regards

ju
Title: SSL HELP THREAD!!!
Post by: gyraf on October 18, 2004, 04:47:11 AM
Hi Ju,

There's not much to do but to check and recheck components, orientation, pcb tracks, and powersupply distribution...

Quote
My meter was working when I first started testing, and now it is pegged ( and stays pegged). Ever run into this, and is there a way to "unpeg" it?


Sorry - I don't understand "Pegged"?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: on October 18, 2004, 06:14:55 AM
Quote from: "gyraf"
Hi Ju,

There's not much to do but to check and recheck components, orientation, pcb tracks, and powersupply distribution...

Quote
My meter was working when I first started testing, and now it is pegged ( and stays pegged). Ever run into this, and is there a way to "unpeg" it?


Sorry - I don't understand "Pegged"?

Jakob E.

pegged - stuck where it is...  on maximum...
I read this as fully stuck over to the right..?
Title: SSL HELP THREAD!!!
Post by: gyraf on October 18, 2004, 06:45:08 AM
Aah - thanks.

If the meter is stuck all the way up, there may be a fault in it. Meters should have an end-stop that prevents this - try taking the meter apart and find and possibly re-set this endstop.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: fum on October 18, 2004, 12:16:47 PM
cool,  that's the path I'm on, just wanted to make sure I wasn't missing a "better" way =)

ju
Title: Malfunction
Post by: axtrak on October 19, 2004, 04:09:52 PM
Hi , i finished my first SLL Clone, one channel works fine, the other outputs only white noise. Where could i start to look for the problem? I checked the PCB, it all looks fine
Title: Re: Malfunction
Post by: Greg on October 19, 2004, 04:12:28 PM
Quote from: "axtrak"
Hi , i finished my first SLL Clone, one channel works fine, the other outputs only white noise. Where could i start to look for the problem? I checked the PCB, it all looks fine


Swap the VCAs (L to R) and (R to L) and see if the dead channel follows either VCA. I hope you socketed them. This way a VCA problem can be ruled out.
Title: SSL HELP THREAD!!!
Post by: mnats on October 21, 2004, 07:47:56 AM
Quote from: "frist44"
I used a 1ma lin scale meter from mouser. I'm just wondering if they resistor should be different because it barey moves during the most extreme compression. I know a couple other people have mentioned this meter, so I'm wondering if if requires a different size resistor.
http://www.mouser.com/index.cfm?handler=displayproduct&lstdispproductid=341715&e_categoryid=643&e_pcodeid=54101

I used the same meter and it works fine with the 2k resistor suggested for 1mA meters. Given the other problems you mentioned in the "SSL issues..." thread you started, the problem must lie elsewhere...
Title: SSL HELP THREAD!!!
Post by: gyraf on October 21, 2004, 07:57:07 AM
Or it's simply a wrong resistor. Try measuring it (power off, and without meter connected)
Title: SSL HELP THREAD!!!
Post by: j.hall on October 22, 2004, 08:01:19 PM
just got my sifam director 14 ppm's in.

the meters read 1 to 7, everything i have read here and on the net indicates they are true linear meters.


does this mean i can pick my value....2k for 20db range or 1k for 10 db range?

meter specs here:

http://www.nrgrecording.de/SIFAM_PPMsatcanford.co.uk.pdf



thanks for all the help,
j.hall
Title: SSL HELP THREAD!!!
Post by: gyraf on October 24, 2004, 05:07:20 AM
Hall,

Yes, if it's a 1mA linear meter that should be right.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: jensenmann on October 24, 2004, 07:49:16 AM
Hi everybody
Since a few minuts I have two wonderfull working Gssl´s in my studio :thumb:  :thumb:  :thumb:  :thumb:
They run with That 2181LA VCAs without Dist trim pots. The meters are Sifam EH30 Edgewise 0-1mA with customscale (0-20dB). It costed me around 160? each and took 6 weeks delivering time since it was a custom order. I´m sorry that I can´t provide any photos but you find the meter right there (german Sifam distributor): http://www.sibalco.de/indexho.html
They make the Gssl look really retro with Jakob´s frontpanel layout. :green:
Now its time to say big, big thank you to all you guys out there who helped me with asking qustions and answering them. Very special thanks to Jakob who gave us this (and not only this) project, provided us with infos, help, knowledge, fun, addiction...  :thumb:
There is on thing to say about this community and it really comes from my heart: if the world would act like you guys are doing here in this community it would be a really better place to live. Thanx
Jens
Title: SSL HELP THREAD!!!
Post by: radiance on October 24, 2004, 08:34:05 AM
Congrats Jensenmann!!
Title: SSL HELP THREAD!!!
Post by: underthebigtree on October 24, 2004, 04:50:56 PM
Hi good people -

I have completed a pair of GSSL's in a single case.  One pair sounds perfect, and worked nearly flawlessly right out of the gate. The other pair has a gain problem, and is not compressing. Somewhere within the system, it is amplifying the signal into clipping. I've gone through it with a fine tooth comb, and cant find it - hopefully someone here can help.

Here are the facts:
1) The signal is fine leading into the 15K resistor before the DBX202 emulation circuit. I am actually using 27K's there for unity gain, but this hasn't changed the problem. I'm using Verbos' DBX chips.

2) The signal is amplified into distortion somewhere before pin 1 of the 5532 opamp (the output of the first half of the chip) leading out of the DBX circuit.

3) Between the 2 points above, I can't read the signal anywhere on my scope (not the greatest scope user), but that does narrow it down.

4) I've replaced all the dbx chips, the TL072, and the TL074 with the chips from the other unit. No change.

Any ideas would help a lot. Many thanks in advance!

Nick
Title: SSL HELP THREAD!!!
Post by: radiance on October 24, 2004, 05:18:43 PM
Did you also replace the ne5534 from the dbx 202 emulation cicuit?
Also: within the dbx emulation circuit are two 1K resistors, check those two and also check the 15K near the ne 5532 in the output section.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 25, 2004, 04:31:06 AM
And compare the control voltages at the VCA - if there's a short around the VCA, gain could go high also..
Title: SSL HELP THREAD!!!
Post by: underthebigtree on October 27, 2004, 04:06:21 AM
Partial success!

The 5534, 1k's and15K mentioned were all fine. Found weird looking waveforms at pin 8 of the left and sidechain VCA chips, which led me to the TL074. Discovered a cold solder joint on the V- there, which must have led to some strange behavior. Repaired that, and the runaway gain problem is gone.

Sadly, not done yet. The unit is passing audio correctly, and makeup gain is working in non-bypass mode, but there is no compression at all, no meter movement, no change in level when moving threshold knob. I'll hunt through this thread to see if anyone else has had this problem. Otherwise, back to swapping chips and comparing the same signal between the 2 compressors until I figure it out.

Many thanks Jakob and Radiance!
Title: SSL HELP THREAD!!!
Post by: gyraf on October 27, 2004, 04:17:05 AM
Depending on where the solder blob was at the TL074, that one could be fried. Try a new one. These are always good to have as spare parts..

Try tracing the sidechain signal through the SC VCA, the rectifier, and timing circuit.

Observe orientation of sidechain VCA!!!

Jakob E.
Title: SSL HELP THREAD!!!
Post by: underthebigtree on November 02, 2004, 02:05:56 AM
Nailed it (finally!)

It was 2 cold solder joints at the wiring harness on the main board wires that connect to the control panel board. It took way too long, and many blind alleys, to discover the problem, but I learned a lot in the process. Thanks, Jakob!

I'll post pix of the completed unit in the next couple of days.

Nick
Title: SSL HELP THREAD!!!
Post by: fum on November 10, 2004, 12:45:20 PM
ok,

I'm trying to verify that these units are working properly, and am having some trouble seeing the output with the scope.  When I hook it up to the crappy little b*ringer mixer on my bench ( says it's balanced in, but maybe it's "semi" balanced), I hear the output of the unit, but when I hook the scope up to it, I don't see anything.

Is there potentially a better way to test this, instead of plugging into a mixer?


Secondly, what kind of crosstalk, if any should I be seeing?  There is none between Right in and Left out, but I got's lots between Left in and Right out.

Regards

ju
Title: SSL HELP THREAD!!!
Post by: Greg on November 10, 2004, 12:54:27 PM
hi fum:

An oscilloscope would be a great way to test.  Do you have one?
Input: waveform to pin 2, connect 1 and 3 together. Output: measure across pins 2 and 3.

And I don't think there should be any crosstalk b/w channels. I didn't have any on my unit.
Title: SSL HELP THREAD!!!
Post by: fum on November 10, 2004, 02:17:17 PM
yup, I'm testing with an oscilliscope,  connected pin 1&3, scoped pin 2 on output, same dealio.

I'm checkin connections, might have a solder blob, but there's definitely crosstalk from the input of 2 to the output of 1, but not vice versa

ju
Title: SSL HELP THREAD!!!
Post by: Greg on November 10, 2004, 02:24:35 PM
On the output, don't connect pins 1 and 3 together. Leave pin 1 open and measure across pins 2 (+) and 3 (-). I did the same thing when testing my first clone.

Not sure what to say about the crosstalk... Gyraf should be around soon and he should be able to give some direction.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 10, 2004, 02:27:45 PM
You'll need to find the place in the circuit where the crosstalk is introduced, by tracing the signal through the unit. Then look closely around that part to see if you can find any shorts...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: fum on November 10, 2004, 03:09:13 PM
Quote from: "Greg"
On the output, don't connect pins 1 and 3 together. Leave pin 1 open and measure across pins 2 (+) and 3 (-). I did the same thing when testing my first clone.

Not sure what to say about the crosstalk... Gyraf should be around soon and he should be able to give some direction.


Sorry, should have been clearer,  tied 1 & 3 on the input.

Define across =).  My scope probe has a ground clip, and a probe point.  Two definitions of across arise.

1.  Leave the ground clip on ground, and probe both 2 and 3 at same time.

2.  Ground clip to 3, probe pin 2.

I'm finding the more that I think I know, the more I know nothing =)

As to the crosstalk, let the tracing begin =)

ju
Title: SSL HELP THREAD!!!
Post by: tmbg on November 10, 2004, 03:14:09 PM
measurements are always referenced to some voltage.  Usually, it's referenced to ground, which would be equivalent of scoping pin 2 or 3 with pin 1 clipped to ground.  You can call that measuring "At 2".  Measuring "across" something means using one side as a reference and measuring the value of the other as referenced to the 'virtual' ground, SO across 2 and 3 would be ground clip on 2 and probe tip on 3 (or vice versa)
Title: SSL HELP THREAD!!!
Post by: fum on November 10, 2004, 03:27:24 PM
thanks for the clarification.

Here's what we got:

Pin 1&3 on input tied, signal to pin 2,

Scope ground clip pin 3, probe pin 2.

Still no disco.  

Connect it to the mixer,  hear the happy sine wave.

yes, I've been having bad electronics karma lately.

ju
Title: SSL HELP THREAD!!!
Post by: j.hall on November 10, 2004, 04:21:31 PM
Quote from: "lictme"
hmmm...If you build an ssl with the 215x circuit in lieu of the 202, can you insert a 202 over the 215x circuit (assuming you pull the 215x and 5532 out of the circuit)?

-james


no one ever answered this.....i'd like to know as i got my hands on some 202's

also, i assume i need to trim the 202's.....is this true?
Title: SSL HELP THREAD!!!
Post by: fum on November 10, 2004, 04:32:09 PM
I'm usin 202's on mine, I left the trimmers in there.  I think I asked at one point, and no one said anything  to the contrary, so I assumed I was good

But don't listen to me, I'm gettin wrung through the electronics wringer these days.

ju
Title: SSL HELP THREAD!!!
Post by: gyraf on November 11, 2004, 03:03:25 AM
I'm not sure I understand the question - but yes, you can build the circuit with two 202's and one 2150 (2151/2155/2180/2181) for the sidechain.

The pcb is laid out to directly accept 202's - simply leave out all components "beneath" these. Which also means: keep the trimmers. If in doubt, check the original ssl schematics for reference..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: j.hall on November 11, 2004, 09:43:54 AM
thanks!!!  that answers my question.

a new problem.....

my first unit is up and running without a single problem.

i finished up the second, put power to it.  i checked power throughout the unit and everything looked great. i put all the chips in and hooked up the daughter board and the 12 volt rail dropped.  the power on LED isn't lighting up.  and the meter is up reading 3 db of gain reduction.

i checked the 12 volt regulators and they have 24 volts into them and noting out.  they are SUPER hot as well.  did i burn them up some how?

the wierd part is that i still have 12 volts on pin 4 and 7 of the 5534 in the emulation circuit.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 11, 2004, 10:48:40 AM
check for psu rail shorts on the front panel board.

Quote
the wierd part is that i still have 12 volts on pin 4 and 7 of the 5534 in the emulation circuit.


Naa. There should be +/-15V here..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: j.hall on November 11, 2004, 01:34:25 PM
Quote from: "gyraf"

Naa. There should be +/-15V here..

Jakob E.


not according to your schematic

http://www.gyraf.dk/gy_pd/ssl/ssl_sch.gif
Title: SSL HELP THREAD!!!
Post by: j.hall on November 11, 2004, 02:33:23 PM
problem solved

i landed the TL074 socket on the PCB the wrong way....so i plugged the chip in backwards.

power wise everything is working now.....i have to pass audio through it to full test it

i hope that chip isn't blown.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 12, 2004, 05:12:36 AM
Quote from: "j.hall"
]not according to your schematic


You're right - but look at the pcb - the 12V's are only for sidechain.

Quote from: "j.hall"
i hope that chip isn't blown.


It is with 99% certainty - when you reverse a TL074, you reverse + and - supplies. It shouldn't survive that.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: j.hall on November 12, 2004, 10:33:00 AM
Quote from: "gyraf"

It is with 99% certainty - when you reverse a TL074, you reverse + and - supplies. It shouldn't survive that.

Jakob E.


that would explain why it powers up now, but is not working well at all.

meter movement is backwards, audio is awful.....i need a new chip!!
Title: SSL HELP THREAD!!!
Post by: j.hall on November 12, 2004, 09:43:09 PM
ok...i put a new tl074 in there.  the left channel is great.  the right channel is barely passing audio.

i checked all the xlr connections, the molex connectors....all that stuff.

could the flipped tl074 have blown a component in the input/ouput stages?

seems unlikely to me as that's all on the 15v rail.  anyway.....

all the chips are fine i swapped them all out and traded positions and such....problem remains constant.

any ideas of where to start looking from here?

thanks,
j.hall
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 14, 2004, 10:56:29 PM
Hi guys, I got a question for you:

Do the shafts of the switches and pots need to be cut down?

The reason I ask is they look a little long to me (like they will stick to far out once mounted on the front panel) and I'd prefer to cut them before I solder them.

Thanks in advance.
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on November 14, 2004, 10:59:15 PM
yes... I ended up filing the switch shafts down a little. Some switches are longer than others, check the datasheets.

Ian
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 14, 2004, 11:32:17 PM
Thanks Ian. Do you remember what length the shafts need to be or how much you took of them?
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on November 14, 2004, 11:33:36 PM
I just measured the length of the pot shafts and made the switches the same. The length will completely depend on the knob you are using and how close you want the knob skirt to be to the front panel.

Ian
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 14, 2004, 11:37:09 PM
Thanks again. :grin:
Title: SSL HELP THREAD!!!
Post by: radiance on November 15, 2004, 10:44:29 AM
@ J.Hall: Try swaping all IC's from the left to the right channel.
That may answer your question. I hope you have everything in sockets...
Title: SSL HELP THREAD!!!
Post by: j.hall on November 15, 2004, 11:15:49 AM
i did that....nothing changed

right channel is still passing audio about 30 db down or more.
Title: SSL HELP THREAD!!!
Post by: Greg on November 15, 2004, 11:23:59 AM
hmm...

well if your rails are fine and all the ICs are fine, then perhaps a resistor/cold joint check in the right channel is next  :?  The problem is probably some passive component I guess.

These cases are usually such a pain in the...
Title: SSL HELP THREAD!!!
Post by: j.hall on November 15, 2004, 11:31:03 AM
yeah....major pain

as far a blown component, everything looks fine.

all solder joints are nice a shiny and looking good, but i haven't started testing them.

figure i'll just pump in 1k tone and track it through with an O-scope.
Title: SSL HELP THREAD!!!
Post by: j.hall on November 15, 2004, 04:24:09 PM
ok.....i located one problem, but i'm not sure if this is the actual problem or just something i caught while checking the unit out.

look at the attached jpg.

if the circled 15k resistor was accidentally switched to a different value what effect would that have on this circuit.  (right when i found it i realized i was late for a meeting, didn't measure it, but it looked like a 10k, maybe a 100R.....can't remember the colors that close right now)

http://download.prosoundweb.com/~j.hall/ssl_sch.pdf
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on November 15, 2004, 05:38:43 PM
If that resistor is lower than 15K, the gain that the op amp is giving will be less than unity. I would guess that it is something low like 100R, which would explain how you are hearing one side down ~30dB or whatever. Definately replace it with a 15k and take a listen.

Ian
Title: SSL HELP THREAD!!!
Post by: j.hall on November 16, 2004, 03:31:02 PM
it was a 120R and once changed to it's proper value of 15k the whole thing is rocking.

thanks!!!
Title: SSL HELP THREAD!!!
Post by: fum on November 17, 2004, 01:06:11 AM
So how long do you guys normally let yourself cook on a problem before checking back and asking advice?  :roll:  

 I'm still laborin over my SSL's, they've been on the bench a few weeks.  I'm ready to be done with them, so that I can put them to use =).

I try to keep a rotation of projects to work on, so I don't burn myself out on one thing ( it can be frustrating to bang your head against the same wall day in and out, I do that enough already), but perhaps I should check in with what I've been up too on these.

I think the majority of my problems are a poor PCB etch.  This was the first board I etched ( over a year ago), and the traces ended up a little blurry.  I've spent a bit of time tracing signals and cutting improper connections.  Found about a half dozen of those.

One of them works well, but has this crosstalk(described above) that I can't track down, as I can't seem to get my scope to show me whats goin on.   I've used the scope with success on projects previous, but something I'm doin aint right(the scope is fine, I'm thinkin it's how I'm using it).

I swapped the main boards between the units, and it helped me isolate better where some problems were.  The unit that works fine, does not when I put it in the other  unit, which told me there's a problem with the control panel layout (either pcb or wiring).  And the one that doesn't work fine, still doesn't work fine in the other unit, which tells me there's still something wrong with the main board too (besides it's control panel ).

Since I can't get the scope to tell me what I want, I've spent some time checking resistances to ground from points in the circuit ( comparing the two), and it has helped track down some problems, but seems somewhat arcane and time consuming.

Supply voltages are a all good.  Audio signal passes through.  I'm still looking into different stuff, but suggestions are welcome

 :grin:

ju
Title: SSL HELP THREAD!!!
Post by: fum on November 17, 2004, 02:46:56 PM
Hah!  Finally some success.   My Fluke checks frequency, so I started using that to trace signal through.  Managed to eliminate the crosstalk, and have one unit up and working correctly.  Again, just a bad etch, with traces connecting where they shouldn't be ( albeit one of them I could not see, even with a magnifying glass, but the continuity check doesn't lie)

One down, one to go   :green:

ju
Title: SSL HELP THREAD!!!
Post by: Steve Jones on November 18, 2004, 02:49:21 AM
I'm sure this has been asked before, but I can't find it - is it OK to use a THATS 2180LC for the sidechain VCA as well as the main GR VCA's? or does the sidechain VCA have to be a diferent type?
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on November 18, 2004, 03:04:40 AM
totally fine steve
Title: SSL HELP THREAD!!!
Post by: Steve Jones on November 18, 2004, 05:04:30 AM
Thanks MacDude!   :guinness:
Title: SSL HELP THREAD!!!
Post by: mich on November 18, 2004, 08:46:03 AM
hi all

trying to troubleshoot my ssl clone ,got some problems,maybe someone can help....

ive got all voltages right (+/-15 and +/-12 )where it should be...

the unit is passing audio in both channels (clean & good) but not compressing at all.the meter (100 uA with the 330R resistor) is not reacting to nothing.. actually none of the controls is working properly.

one funny thing- the make up gain pot-when turned to 0 resistence is turnning the power led off..

also checked ac signal coming in on pin 7 of tl074(o.k) but nothing on pin 8......................any ideas?

im also confused with the meter resistor-having read somewhere that it should be 20k instead of 2k for a 100uA meter (posted by jakob) and the schematic calls for this 330R...

thanks.
Title: SSL HELP THREAD!!!
Post by: mich on November 18, 2004, 08:56:02 AM
sorry, i didnt mention i am using verbos dbx 1252 vca's.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 18, 2004, 09:02:50 AM
Mich,

Check for shorts on your control-panel board - specially from makeup-gain pot wiper to +/0/- rails.. Check value of the resistor in series with makeup-gain pot wiper.

Have you tried reading through this thread? I think we've had that symptom before..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mich on November 18, 2004, 09:13:31 AM
thanks jakob, ill check that.
yes, i read through the whole thing....(19 pages)....
Title: SSL HELP THREAD!!!
Post by: mich on November 18, 2004, 10:00:07 AM
that was the fastest troubleshoot ever....thanks jakob. :grin:
the wiper was definitly touching the 0 rail- through the bypass switch that was conected upside down - A and C points of the bypass switch- i think its wrong on the schematic? anyway now the meter is working but ive got distortion when threshold is high....ill go back to reading this thread...
Title: SSL HELP THREAD!!!
Post by: ChrisA on November 19, 2004, 03:27:52 AM
So, I've built two ssl clones that came out great...Thanks Jakob and to everyone else here...this forum is amazing.

I was just trying to finish up my third clone and ran into a strange problem I haven't come across before...It passes audio fine with the threshold wie open and gain all the way down... i'm also sure all of the vcas are working and in right, but its doing some very strange stuff.

The main weird symptom is when I turn the make up gain pot it creates a spark inside and the pot actually starts to fry...the threshold pot isn't really working quite right either and it is intermitently compressing....when it does it is also distorted...

I've started checking all the resistors and can't find any mistakes yet swaped out all of the chips and its still giving me the same problem...

from these symptoms...any ideas of the best place to focus on where the problem might be?
Title: SSL HELP THREAD!!!
Post by: gyraf on November 19, 2004, 04:24:39 AM
Chris,

Check - like Mich did - for shorts from pot wipers to -/0/+ rails. Check pot wiper series resistors and values. Try measuring what voltages you get at the pot wipers when you turn them - the schematic gives a good clue to what the voltages should be.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mich on November 19, 2004, 09:18:06 AM
hi again.

still troubleshooting....

now bypass works,make up gain works and the meter is responding,but
on fast attack time its cliping like crazy..& i hear no compression-only at fastest attack and high threshold there is some compression hapening-but with distortion.

someone have any ideas on where to search?...

p.s: i also noticed that the tl072 is reversed on the schematic or the pcb,but i  guess its only the stages numbers on the chematic.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 19, 2004, 09:31:08 AM
Hi Mich,

Yes, the two halves of the TL072 are switched between schematic and PCB.

Is your timing circuit working right, giving relatively slow changing DC with signal?

There is a small jumper on the front panel pcb (near the centre where the incoming wires attach) that will prevent timing from working if it is left out by error. check that this jumper/wire link is mounted correctly. This has been a known error before.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mich on November 19, 2004, 09:56:51 AM
timing circuit works, and the jumper is mounted correctly...
Title: SSL HELP THREAD!!!
Post by: mich on November 19, 2004, 11:18:36 AM
another question...

the bypass switch can easily be replaced by a toggle switch like a simple dpdt (double pole double throw) right?
maybe i have it conected wrong?

                    on        com     off
                     *           *       *
                     --          --      --
 
                     --          --      --
                      *           *                        bypass  - (or this conection or jumper on control pcb)
                      make up
thats the way to conect the bypass-right?
Title: SSL HELP THREAD!!!
Post by: tmbg on November 19, 2004, 01:23:09 PM
For the 5534s, I can't seem to get the N or AN!  Mouser suggests the NJM5534D as a replacement... or I can get the TI NE5534D or AD....

whats the difference here?
Title: SSL HELP THREAD!!!
Post by: tmbg on November 19, 2004, 02:35:59 PM
Also, can the 0.1uF poly caps be 63V instead of 100V?  the 100V ones are backorder only :/
Title: SSL HELP THREAD!!!
Post by: mich on November 19, 2004, 02:59:30 PM
i dont think you will find voltages greater then 24v in the circuit..

the threshold pot is going from -12v to +12 for feeding the sc and the sc compreses more or less depending on this voltage.(if i understand corectly :roll: )
Title: SSL HELP THREAD!!!
Post by: ChrisA on November 19, 2004, 05:04:04 PM
thanks jakob for pointing me in the right direction with my last question...I resolved that problem, but have another one.

This ssl is extremely loud... more than the others I made by about 6 db....All of the resistirs look right...It also has a hum problem which my others didn't using the same ground scheme....when I power it on the first time after being off for a while it doesn't compress at all...If I switch it off really quick, then turn it back on it starts compressing...ratios, attack and release all seem right, etc...still loud though....if I turn it off and let it sit and then turn it back on a few minutes later....no compression again...its completely repeatable...weird, right?...I'm wondering what this kind of behavior could possibly be.


any suspects come to mind for this? could it be a cap somewhere?

thanks!

btw- when I first powered up this ssl I forgot to put the jumper that goes  behind the 7915 and 7185....I then put it in and have been having problems...could I have hurt something over there by doing that?
Title: SSL HELP THREAD!!!
Post by: mich on November 19, 2004, 10:13:30 PM
found it! :grin:
like most of my debuging,it comes down to the pcb....
a veeery small piece of sh*ti coper in the main board-conecting points G and D- and freaking out the tl074(it created  feedback between the out and the non inverting input of the stage that drives the meter).

it took me the whole freaking day,but the sound of the unit now-is worth it.....thank u jakob - great project!-and thanks everyone else for helping.

ill post some pics when ill get it looking sharp....

cheers
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 19, 2004, 10:30:22 PM
Hi Guys. I'm nearing completetion of this project and got a question before I power up and test this thing.

On the control PCB (to the right) next to the 750K Resistor there are two points between 'A' + 'A2', there is a line joining them. Is this a small jumper?

These 2 points connect to the BYPASS Rotary switch and to me there is no reason they could not have been joined on the trace side of the PCB, that's why I'm asking.

Thanks in advance.
Title: SSL HELP THREAD!!!
Post by: Mendelt on November 20, 2004, 05:11:37 AM
Hi, this is my first post here, so just ignore me if I sound stupid

I'm just starting building one of these compressors and there's one thing i'd like to do different.
I usually like rows of leds better for metering than normal meters (and it's a lot cheaper). Is it possible to replace the meter with for example a LM3916 and a couple of leds?
I understood the LM3916 works like a VU meter and i read the meter used in the SSL is different but I'm not really sure about how it's different. Is it possible to build some stuff around the LM3916 chip to emulate a meter for the SSL or are there other chips that could be used for this?

Thank you.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 21, 2004, 05:45:58 AM
Mendelt,

Welcome to "The Lab"..!

Quote from: "Mendelt"
Is it possible to replace the meter with for example a LM3916 and a couple of leds?


Yes - no problem. You will need a linear-scale LED driver circuit, not a dB scale one. This because the VCA control voltage (and thus the meter indication voltage) is linear dB/V.

Quote from: "BladeSG"
On the control PCB (to the right) next to the 750K Resistor there are two points between 'A' + 'A2', there is a line joining them. Is this a small jumper?

These 2 points connect to the BYPASS Rotary switch and to me there is no reason they could not have been joined on the trace side of the PCB, that's why I'm asking.


This is the optional makeupgain-bypass. If the jumper is installed, you will have constant makeup. If it is wired to the switch, you will have makeup only when compressor is "IN"

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 21, 2004, 06:04:32 AM
Thank you Jakob again for your help.

I 've finished soldering the boards and powered it up earlier today. Not good so far, BUT I think I know why....

The 15+15V toroid is supposed to be wired in series to provide the board with 30V.

Is this correct?

Thanks again.

Steve.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 21, 2004, 06:13:05 AM
Yes, the board needs 15-0-15V AC - which is 30V AC between outer connections.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 21, 2004, 06:16:59 AM
Thanks again Jakob, it's much appreciated.  :cool:
Title: monacor
Post by: EEMO1 on November 21, 2004, 06:34:49 AM
does monacor have a meter that would suit the ssl comp? i have easy access to those, so...

 -eero
Title: Re: monacor
Post by: gyraf on November 21, 2004, 06:37:05 AM
Quote from: "EEMO1"
does monacor have a meter that would suit the ssl comp? i have easy access to those, so...


They surely have some that will work - but IMHO not anyone that looks good.

Jakob E.
Title: like this one
Post by: EEMO1 on November 21, 2004, 10:27:03 AM
http://www.monacor.com/int/en/produktseite_monacor.php?artid=1763&spr=EN&typ=u


 like this one? i think it doesn't look that bad... with a black face it could be alright...
Title: SSL HELP THREAD!!!
Post by: gyraf on November 21, 2004, 11:08:56 AM
Yes, it would definitely look better with a black face (you would have to paint the needle white then). But I don't think it'll fit a 1U frontplate.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: radiance on November 21, 2004, 05:21:04 PM
One thing that is not clear to me is:

Are the outputs off the SSL clone ?pseudo balanced? or  are they a  so-called ?cross coupled output stage??

I'm  asking because I'm making insert cables and a came accros some terms I did not understand.
Title: SSL HELP THREAD!!!
Post by: BuzAllen on November 22, 2004, 01:18:58 AM
Quote
Are the outputs off the SSL clone ?pseudo balanced? or are they a so-called ?cross coupled output stage??


From looking at these schematics http://www.gyraf.dk/gy_pd/ssl/ssl_sch.gif the outputs are differentially driven and impedance balanced outputs.  They are not cross-coupled, nor (depending on what they mean) psuedo-balanced.  That is if by psuedo balanced they mean matching ouput impedances but only the hot leg driven.

Brian
Title: SSL Parts
Post by: bubba_b on November 22, 2004, 02:28:50 AM
My first post! This is a great place and all you guys seem really helpful to each other. Nice to see and thanks in advance for any help you can give me.
Anyway, I'm building my first SSL clone, also my first DIY. I've found pretty much all the parts I need except I'm having a hard time finding a transformer. I'm getting most everything from Mouser, but the transformer I'm lost on (there's just so many different ones I don't know which one's right). If anyone has part no.'s and places to go, I'd be very grateful. Also, I need the PCB's. I saw the link to audio kitchen somewhere and emailed them, but haven't heard back. Any other options for pre-made PCB's?

I'm sure once I get going on this, I'll be back with more questions and good news of success.  :grin:
Title: SSL HELP THREAD!!!
Post by: gyraf on November 22, 2004, 03:38:46 AM
Bubba,

Welcome to "The Lab".

For PCB's see "The Black Market", our trading section.

Your transformer question is better answered by someone in your local neighbourhood.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 22, 2004, 06:18:44 AM
Hi Guys,

I've finished soldering the PCB's for this project and after initially only giving the board 15VAC from the toroid, worked out it needs 30VAC (thanks to Jakob). So I rewire the toroid and power up again.

The problem I'm having is distortion. The controls seem to be working, but both channels are distorted. I measured at the + and - jumpers:

+14.83V
-   4.30 V

This led me to beleive the 7915 was at fault until I disconnected the Control PCB and measured these jumpers again. This time with the Control PCB disconnected I get:

+14.83V
- 15.10V

I've checked the Control PCB for shorts and incorrect parts and all looks good. Also rechecked the wires connecting the Control PCB.

Any ideas?

Thanks in advance.
Title: SSL HELP THREAD!!!
Post by: radiance on November 22, 2004, 06:30:46 AM
Thanks BuzAllen.
This is what I came accross about pseudo balancing:

"...Quite commonly seen is the plain ?pseudo balanced? phase/antiphase output, where the equipment?s internal unbalanced signal is simply fed to signal + out (XLR pin 2) by means of an opamp buffer and is fed to signal ? out (XLR pin 3) simply by means of a polarity inverting opamp. This doesn?t implement a true balanced output and rather can be looked upon as a pair of unbalanced outputs, one being polarity inverted. ... "

I thougth that the SSL clone output stage was pseudo balanced but I might be wrong here.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 22, 2004, 06:47:03 AM
BladeSG,

I think you can be pretty sure there is an error somewhere on the control pcb. Check for anything shorting to or connecting to the -12V rail.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 22, 2004, 07:02:28 AM
I'm sorry but I don't know which are the 12V rails.

Thanks again Jakob.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 22, 2004, 07:05:57 AM
Look at the schematic. Look at the layout. Look at the PCB. There is a -12V (and a +12V) circuit that starts with the 79L12 regulator, and (amongst others) goes to the control pcb.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 22, 2004, 07:45:14 AM
Jakob, there doesn't appear to be anything shorting or touching.

Thanks,

Steve.
Title: SSL HELP THREAD!!!
Post by: mich on November 22, 2004, 08:00:12 AM
something is shorting.......but you'll find it.

i had one pin of the molex conector (that conects the two boards-at the main board) shorting another.......actually it was the pcb istelf-a trace touching when it shouldent.....animo.....
Title: SSL HELP THREAD!!!
Post by: mich on November 22, 2004, 08:03:50 AM
p.s - u also have to check with a ****inuity meter - cause many times you dont see the problem, but its there..

most of the modern DMM have this meter in diode checking setting.

hope it helps
Title: SSL HELP THREAD!!!
Post by: Greg on November 22, 2004, 08:52:46 AM
I've noticed that alot of problems with SSLs result from shorting (ie solder blobs) and/or cold joints... I'd recommend that evertime to solder a component in, you test continuity with points its connecting to, as well as check to make sure it's not shorting nearby points. It might take you an extra hour or two to build, but it'll save you headaches in the long run.

I've done this with everything I've built and everything has worked on two GSSLs and a G1176...
Title: Re: SSL Parts
Post by: tmbg on November 22, 2004, 09:19:03 AM
Quote from: "bubba_b"
My first post! This is a great place and all you guys seem really helpful to each other. Nice to see and thanks in advance for any help you can give me.
Anyway, I'm building my first SSL clone, also my first DIY. I've found pretty much all the parts I need except I'm having a hard time finding a transformer. I'm getting most everything from Mouser, but the transformer I'm lost on (there's just so many different ones I don't know which one's right). If anyone has part no.'s and places to go, I'd be very grateful. Also, I need the PCB's. I saw the link to audio kitchen somewhere and emailed them, but haven't heard back. Any other options for pre-made PCB's?

I'm sure once I get going on this, I'll be back with more questions and good news of success.  :grin:


Take a look at Digikey part number  TE62053-ND .  That's a 15VA 15/0/15 toroidal power transformer that should do nicely :)
Title: SSL HELP THREAD!!!
Post by: BuzAllen on November 22, 2004, 10:17:00 AM
Quote
Thanks BuzAllen.
This is what I came accross about pseudo balancing:

"...Quite commonly seen is the plain ?pseudo balanced? phase/antiphase output, where the equipment?s internal unbalanced signal is simply fed to signal + out (XLR pin 2) by means of an opamp buffer and is fed to signal ? out (XLR pin 3) simply by means of a polarity inverting opamp. This doesn?t implement a true balanced output and rather can be looked upon as a pair of unbalanced outputs, one being polarity inverted. ... "

I thougth that the SSL clone output stage was pseudo balanced but I might be wrong here.

That being the case, you were right.  That being the definition for psuedo balancing then yes, the ouput in the gssl schematic would be psuedo balanced.  Sorry bout the confusion I guess I wasn't quite as sure as a I thought about what was meant by psuedo.

By this then I am guessing that a true balanced by these definitions would need to be floating (i.e like a xformer. )  All these different definitions for balanced can be confusing as I have seen many different layouts use then   labled with the same name.  

I just did a search on the web for 'pseudo balanced' and found another definition (which doesn't surprise me at all):

"There are many products on the market that add XLR connectors to an internal single-ended circuit. Such designs, while sporting XLR connectors, don't process the signal in balanced form. It is fair to call such units 'pseudo-balanced' "

So as usual I am still at a loss for real definitions on this.  In school I learned that the term 'balanced' refered to the balanced or equal output impedance on both the cold and hot leg, regardless of whether both legs were driven.  'Differential' was used to define whether the cold leg was driven oposite polarity and 'floating' indicated floating signal lines (i.e. like a transformer)

If interested here are a couple of links to sights that go over this stuff:

A really good paper by Bill Whitlock of Jensen Xformers:
http://www.jensen-transformers.com/an/an003.pdf

Also, try this for questions on interconnecting bal/unbal gear:
http://www.dself.dsl.pipex.com/ampins/balanced/balanced.htm

Brian


Brian
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 22, 2004, 11:03:04 AM
Thanks gyraf. I'll check it out.

tmbg: Found it, thanks. One thing I forgot to specify, though and maybe you already assumed this, but I can't tell from the description. Is this trafo for 220V or 110V? Im in the US. I keep forgetting that's an issue.

On a side question, how feasible is it to make this clone a dual-mono compressor, besides just adding a second set of controls? Has anyone tried this, or is it too much trouble to bother with?
Title: SSL HELP THREAD!!!
Post by: gyraf on November 22, 2004, 11:11:24 AM
Quote from: "bubba_b"
On a side question, how feasible is it to make this clone a dual-mono compressor, besides just adding a second set of controls? Has anyone tried this, or is it too much trouble to bother with?


We've discussed this several times. Use search to find these. But in short, no, a mono version is not feasible.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 22, 2004, 11:21:43 AM
Ok, was just curious. Thanks for the quick and simple answers.
Title: SSL HELP THREAD!!!
Post by: tmbg on November 22, 2004, 11:54:41 AM
Quote from: "bubba_b"

tmbg: Found it, thanks. One thing I forgot to specify, though and maybe you already assumed this, but I can't tell from the description. Is this trafo for 220V or 110V? Im in the US. I keep forgetting that's an issue.


It's BOTH! :D

Wire the primaries in parallel, and it's 110, wire them in series and it's 220.  220 draws half the current at twice the voltage, which is exactly the same amount of power.  Isn't math fun? :)
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 22, 2004, 12:02:39 PM
Excellent! Thank you.
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 23, 2004, 12:08:03 AM
Ok, so I've ordered up all my parts except for the knobs, case and meter. I've heard it said not to use a VU meter, but a mA meter. Knowing that the meter isn't the most crucial element to this unit, could I use an LED meter instead? I'd prefer to use the needle style, just wondering if anyone's used an LED on this before.

Sifam has an audio meter I really like, but it's an audio meter (the AL20). I'm assuming from their description it's not right for the GSSL? If not, too bad. It looks tight!
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 23, 2004, 01:56:40 AM
Thanks Mich & Greg.

Checked and rechecked visually and still cannot find anything that shorts. However I did find that the + wire and F wire from the Main PCB to the Control PCB are shorted. I would imagine that this is OK as both these tracks on the Control PCB end up at or going through the + and middle connection to the 50K Threshold Pot, so the short is actually the Pot itself?

Steve.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 23, 2004, 03:34:26 AM
Quote
so the short is actually the Pot itself?


Only when the pot is turned to one extreme. Turn it to the middle and re-measure.

Your problem is probably in something loading the -12, not the +12.

Double-check connections and component values..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 23, 2004, 04:06:35 AM
Thanks Jakob, that is correct with the pot turned to one extreme it shorted and in the middle not.

Found something I think is weird, the 1M8 resistor on the Control PCB was only reading 680K. So I replaced it with a new one from the same bag as the original (rechecking before I soldered it) and it's the same. Only reading 680k when I measured it at 1.806M before I soldered it. Is this normal? Doesn't seem right to me as the 1M2 above it reads 1.2M.

Steve.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 23, 2004, 04:43:39 AM
Bladesg,

You can't measure the 1M8 in-circuit - look at the schematic; it is paralled by other components. The 1M2 is not (unless ratio switch is at 1:10 position)

Generally, if you measure resistors in-circuit and get an unexpected value, you have to lift one leg of it and re-measure in order to avoid this type of paralleling-problem...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 23, 2004, 05:09:15 AM
Thanks again Jakob, that makes sense.

The only other thing I can comment on so far is that for some reason the longer the Main PCB is powered up for (without Control PCB attached) the lower the +15V Rail becomes. The -15V rail is staying constant at -15.1V. The + Rail starts at +14.83 and after about 5 minutes gradually drops to about +14.20, although I did see it go below 14V at one point.


Thanks for your patience Jakob.

Steve.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 23, 2004, 05:29:33 AM
How are your +/-12V rails doing?

Are you drawing current for a meter lamp? If so, try removing that for now.

Are your 7815/7915 regulators getting too hot to touch? In that case, they may need a bit of heatsink (isolated from each other!!)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 23, 2004, 06:14:25 AM
With Control PCB disconnected

-15.1V @ -15V Rail
+14.2V @ +15V Rail

-15.1V @ Rail outside Left VCA parallel to 2 47K Resistors.
+11.96V @ Rail between 78L12 & 100nF Capacitor
+11.96V @ Rail next to Sidechain VCA and 3K9 Resistor.
0V @ Rail between TL072 & 100R Resistor
0V @ Rail between 7915 and 1000uF Capacitor.

*The 7915 is getting too hot to touch

With Control PCB connected

-4.3V @ -15V Rail
+14.8V @ =15V Rail

-4.2V @ Rail outside Left VCA parallel to 2 47K Resistors
+12V @ Rail between 78L12 & 100nF Capacitor
+12V @ Rail next to Sidechain VCA and 3K9 Resistor
+0.7V @ Rail between TL072 & 100R Resistor
0V @ Rail between 7915 and 1000uF Capacitor

* The 7915 is not getting as hot with the Control PCB connected, hence the +15V Rail is not dropping.

No meter or meter light has been connected yet.

I cannot find a -12V Rail. I probably don't know enough about electronics and probably shouldn't have done this project. Thanks again Jakob and everyone else for your patience. I will certainly consider buying new PCB's and starting over.

Steve.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 23, 2004, 06:30:29 AM
I should also mention that I have not soldered a power LED to the Control PCB, as I was going to put a power switch with light.

Steve.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 23, 2004, 07:03:43 AM
Trace the -12V rail from the -12V regulator, the 79L12. Check where it goes on the control pcb. On the control pcb, it is the bottom trace that goes to the threshold pot. Check that this does not short to anything - including chassis and the 0V line that is right next to it where it connects to the main pcb.

Measure -12V voltage with/without control pcb connected.

Use an ohmmeter to check for continuity between 0 and - on the control pcb (see the pdf layout file for reference)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 24, 2004, 03:02:47 AM
Thanks again Jakob. I measured -12V from the - output pin (that goes to control PCB). The fault is intermittent now as I was getting +12V & -12V and also +14.8 & -15.1 even with the Control PCB attached. I noticed that fiddling with the Bypass Switch and Threshold and MakeUp pots cured the problem momentarily. I also noticed that turning Threshold pot past half way yeilded the longest periods of normal operation ( and yes this thing sounds sweet when it's not distorting).

When the Control PCB is disconnected I'm always getting -12V at the - output pin. With the Control PCB attached it fluctuating between -12V and -4V.

I'll try changing these pots and Bypass switch tomorrow and see if it makes a difference.

Steve.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 24, 2004, 06:35:20 AM
Here's something funny for you all.

I was just in the process of re-soldering some joints on the Control PCB and a couple on the Main PCB in the hope there was a bad joint somewhere.

Now the -15V Rail is OK even when the Control PCB is connected. However the +15V Rail now drops to +5.4V when the Control PCB is connected.

And no I did not have the polarity of the DMM probes around the wrong way, even I thought this at first until I double then triple checked it.

I'll have another look tommorow.

 :grin:
Title: Another question
Post by: Mendelt on November 24, 2004, 07:07:54 AM
Thanks for helping me with my led-display question last week seem's i'll be using an LM3914 with a linear scale. I have another one for you if you don't mind.

I was planning on building two compressors in one 2u case to keep costs down.

Is it possible to drive two compressors from one powersupply? How much current does one compressor draw? I saw you can draw approx. 1A from the 78/912 and 78/915's but i have no idea what one compressor would need.

To make matters worse I would like to drive a couple of led-bars to display input signal and gain reduction and I would like to drive these from the same powersupply too.

thank you,
Mendelt Siebenga
Title: SSL HELP THREAD!!!
Post by: gyraf on November 24, 2004, 07:19:07 AM
Mendelt,

You could have +/0/-15V supplies on one board, and link these to the second board. But you'd need to do some thinking to get it right - it may be easiest to just use two psu transformers.

For the meter, I think a separate psu would be safest - noise and all.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Mendelt on November 24, 2004, 07:58:07 AM
I was hoping I could use one transformer connected to a seperate board that provides +/- 15 and +/- 12 volts to both compressors (the PSU schematics look kinda easy to build separately on a stripboard).
But maybe thats not such a good idea after all.  :?
I think i will try using one transformer to power both psu's on the boards. I can then try to make my own psu for the led-stuff.

thanks,
Mendelt Siebenga

Quote from: "gyraf"
Mendelt,

You could have +/0/-15V supplies on one board, and link these to the second board. But you'd need to do some thinking to get it right - it may be easiest to just use two psu transformers.

For the meter, I think a separate psu would be safest - noise and all.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 24, 2004, 08:37:17 AM
If you build an off-board powersupply - which is not a bad idea - you should make it +/-15V only, and keep the +/-12V regulators on the PCB's. This because you need a stable local reference.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 25, 2004, 04:29:32 AM
Just done some more fault finding and it now seems apparent that the +15V rail is dropping intermittently with and without the Control PCB attached. The one thing I have found is that even with the + & - 15V rails being as they should the sidechain VCA's Pin 5 is always @ -8.7V.

I also found that Pin 4 of the TL074 always gets +12V so long as the +15V rail is @ +14.8V. Pin 11 of the TL074 fluctuates with and without the Control PCB attached from -12V and then drops to about -6V. This pin 11 can be at exactly -12V and pin 5 of the SC VCA still at -8.7V.

When Pin 11 of the TL074 is showing -6V the voltage at pin 5 of VCA also drops below -8.7V to around -5V.

I'll have a rest from it for a while and get back to it later tonight.

Steve
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 25, 2004, 10:55:29 AM
Done some more testing with the control PCB disconnected. Also re-soldered most of the main PCB's points and replaced the TL074, SC VCA and the 22uF 25V Cap outside SC VCA that leads to the 79L12.

Found the 15V Rails OK. Just noticed that the left and right VCA's are only getting about -8V at pin 5 but the full +15V at pin 7. NE5534's in left and right VCA's are getting correct voltage. NE5532's & NE5534's in the I/O section are getting correct voltage too. SC VCA does also get +12V @ Pin 7.

Look at it again tommorow. :sad:

Steve.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 26, 2004, 06:09:42 AM
I didn't take into account the resitor that is in line of the -V input to VCA's, so they're likely to be OK.

If there is a short cicuit somewhere on either PCB is it possible for the voltage to drop between the rectifier (W04) and the Regulator's (7915 & 79L12?

Checked the 1000uF Cap and 10R resistor between W04 and 79L12 and they seem to be working fine. replaced 79L12 just in case.

Is it also normal for the negative output of the W04 to fluctuate up to -24V when using ground as reference? The voltage here varies wildly from anywhere between -9 and -24V intermittently and sometimes actually sits at -15V as I think it should.

To me this doesn't seem normal.

Any help would be greatly appreciated.

Thanks,

Steve.
Title: SSL HELP THREAD!!!
Post by: BladeSG on November 26, 2004, 11:32:40 AM
Thanks guys.
Title: SSL HELP THREAD!!!
Post by: Twin-x on November 26, 2004, 03:01:23 PM
Are 1000uF/50V ok or do they have to be 35V

Second question i ordered NE5532 but i got NE5534P from the company.
The NE5534 i order were NE5534N

Is the NE5534P the same as the NE5532????
Title: SSL HELP THREAD!!!
Post by: gyraf on November 26, 2004, 03:04:33 PM
1000uf/50V is alright, if you can fit them on the PCB. Higher voltages are always alright.

And no, NE5534 and NE5532 are different opamps. '34 is a single, '32 is a dual.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Twin-x on November 26, 2004, 03:06:32 PM
Thank you Jakob!
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 26, 2004, 06:18:24 PM
This may be a dumb question, but I'll ask anyway. The parts list for the gyraf SSL give alot of Jaycar part #'s. I'm in the US, so I went through mouser to get most everything. All the resistors up to 1M are ½W, 1% metal film. How crucial is it that these be metal film? Would carbon work just as well and how important is it that they be 1% as opposed to 5%? All the local places I went either had 5% metal film or no metal film at all.

On a differrent subject, I got a milliameter that's a Simpson and has the # 20366 on the back. I got it at a reclamation center so no more info's available, other than it goes from 0-5 on the display and is DC. Is this usable for the GSSL? If a pic helps I can post one.
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on November 26, 2004, 06:25:27 PM
Carbon resistors are fine. 5% is probably just fine as well. I would, however, buy 1/4 watt resistors and NOT 1/2 watt resistors. The PCB layout is a little cramped as it is.

Ian
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 26, 2004, 06:59:32 PM
Cool, thanks. That'll help with future projects. Anything you can tell me about the meter?
Title: SSL HELP THREAD!!!
Post by: mnats on November 26, 2004, 07:29:03 PM
Most modern 1/2 watt metal film resistors sold today are the physical size of typical 1/4 watt carbon films and will fit in the SSL.
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 27, 2004, 12:45:36 PM
Quote from: "gyraf"
For the meter to the SSL you'll need a linear 1mA fsd type, NOT a VU-meter.

....100uA, but will work with a different meter resistor (20K in stead of 2k)

Jakob E.


So, if I'm seeing this right, it doesn't really have to be a 1mA meter, so long as it's measuring amps and has the correct resistor size on it? Suppose I have a 5mA meter (ok, I do have a 5mA meter), I would just need to change the resistor size to something like a 400R? Is that right?

Here's what it looks like if you wanna know:
http://pg.photos.yahoo.com/ph/adum_j/album?.dir=f470
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 28, 2004, 01:20:01 AM
bumpity-bump
Title: SSL HELP THREAD!!!
Post by: PRR on November 28, 2004, 02:08:53 AM
> it doesn't really have to be a 1mA meter, so long as it's measuring amps and has the correct resistor size on it?

Yes, except there is some limit on the current. I don't have the plans handy, but if the meter comes from a chip, 10mA or 20mA is about the most you can be sure of. If you are in love with a junkyard 1-Amp meter, you can add booster-transistors (and a bigger power supply).

> bumpity-bump

What is this 2-hour bump?
Title: SSL HELP THREAD!!!
Post by: tubejay on November 29, 2004, 04:20:01 AM
My GSSL Comp freaked on me tonight.  It's over half as quite on one channel.  I rewired the I/O jacks, checked continuity on all points, and the problem is still there.  It was fine up until tonight.  Any ideas why one side would all of the sudden get quieter?  It still compresses everything just fine on both sides.

Any thoughts on this would be appreciated.

Cold solder joint??
Title: SSL HELP THREAD!!!
Post by: radiance on November 29, 2004, 08:28:15 AM
Yes, a  cold solder joint might be it. Did you work on your SSL lately?
One time I had a similar problem and it was caused by a very small piece off wire which produced a short. Probabely came off when stripping a wire.
Title: SSL HELP THREAD!!!
Post by: Emperor Tomato Ketchup on November 29, 2004, 10:55:23 AM
I've read through this whole thread, but I don't think that I have seen the my exact problem discussed yet.  I've built two GSSL's with the DBX's from Verbos, boards from Gustav.  All my voltages seem fine, and metering and controls work fine.  In fact, everything seems to be perfect except for a rather unmusical distortion that increases with the amount of compression.  Bypassed, the units are passing pristine audio.  I have tested both mainboards with the same control board, so either I made the same mistake on both mainboards, or my control board is the problem.  I've run through the control board a couple of times and still cant seem to find anything wrong.  I do have the jumper in place there as well.

Does this problem make sense?  Is there some way that an error in the sidechain circuit could cause the signal VCA's to distort the audio that they are passing?

-Chris
Title: SSL HELP THREAD!!!
Post by: tubejay on November 29, 2004, 11:47:47 AM
Which DBX VCA's did you use?  Did you use a distortion trimmer?
Title: SSL HELP THREAD!!!
Post by: Emperor Tomato Ketchup on November 29, 2004, 01:04:23 PM
Jay,  I used the DBX c1252h2 from Mark Verbos.  Turning the distortion trimmers fully in each direction didn't seem to have any effect, positive or negative.
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 29, 2004, 03:10:24 PM
Thanks PRR. So I'm guessing my math is right in using a 400R on the 5mA meter? Just don't wanna assume anything, but it makes sense to me.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 30, 2004, 09:04:27 AM
TK - check if your timing circuit (attack/release) is working right..

Jakob E.
Title: 1000 caps
Post by: EEMO1 on November 30, 2004, 11:20:04 AM
umm.... just looked at the pcb and my parts, the parts list i use has 2x 1000u/63v caps but the pcb has 1000u/35v printed on to it...

 which one is it? does it depend on something? i got to of both so i want to know which one to solder in...

 thanks,

 eero
Title: SSL HELP THREAD!!!
Post by: gyraf on November 30, 2004, 11:25:10 AM
both 35V and 63V will work..
Title: SSL HELP THREAD!!!
Post by: daArry on November 30, 2004, 02:17:42 PM
Hey bubba, what res value did you go with for ya 5mA meter then? I'm wondering on a appropriate one for mine - which is a 5mA meter too i believe (was 25mA but i removed this wirewound resistor lookin thing which knocked it down to 5mA)... how did u work out the value of 400R?

Cheers
Title: SSL HELP THREAD!!!
Post by: bubba_b on November 30, 2004, 02:26:16 PM
Don't know if it works yet. I haven't heard back on if it's right yet, but I got 400R from what Jakob said about a 2k on the 1mA and a 20k on the 100uA. 1/10 the amperage gets 10 times the resistance, so I thought maybe it works the same the other way, ie: 5 times the amperage gets 1/5 the resistance. I could be totally wrong, but I'll let one of these other pros step in and verify. Anyone? Beuller? Beuller?  :?:  :grin:
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on November 30, 2004, 02:29:55 PM
That makes sense bubba, BUT you have to make sure that whatever is driving the meter can source the higher current you are asking of it. I don't really know off the top of my head for the TL074.

Ian
Title: SSL HELP THREAD!!!
Post by: fum on November 30, 2004, 07:38:18 PM
Ok, final update.  I've got both my SSL's working finally. The final problem had to do with a faulty 202 VCA in one channel ( would pass audio at a lower level, but without compression).

They are both happy now.  Time to rackem!  Thanks Jakob!

ju
Title: SSL HELP THREAD!!!
Post by: tubejay on November 30, 2004, 08:44:40 PM
Quote from: "radiance"
Yes, a  cold solder joint might be it. Did you work on your SSL lately?
One time I had a similar problem and it was caused by a very small piece off wire which produced a short. Probabely came off when stripping a wire.


I bet we had the same pins shorted.  I had pins 2 and 3 or 1 and 2 shorted  (I can't recall which it was now) on my 5532 output amp.  It was caused by a little fleck of solder.  It does not appear that I have done any permanent damage.  I fixed the short, and it sounds perfectly fine to me.  I have yet to do a thorough test with some tones at the studio, but it appears to be fine now.

So if anyone has a similar problem (one channel quite a bit quieter than the other but still compressing just fine), check pins 2 and 3 or 1 and 2 of your 5532 output on the quiet channel, to ensure there is not a short.


Thank you Radiance for giving me a good starting point!
Title: SSL HELP THREAD!!!
Post by: Emperor Tomato Ketchup on December 01, 2004, 02:40:33 PM
Quote
TK - check if your timing circuit (attack/release) is working right..


Jakob,

I finished my second control board and replaced the original.  The problem is much better, but I still have some distortion on low frequencies, particularly at short attack/release settings.  I know that it is common for some compressors to distort on low frequencies with short attack/release, but I am testing with a sine-wave audio generator sending a constant amplitude tone through the system.  This time I could hear more distortion with the trimmer adjustment, but I couldn't get rid of it all.  Any ideas?

Thanks,
Chris
Title: SSL HELP THREAD!!!
Post by: tmbg on December 01, 2004, 06:10:22 PM
just got my PCBs from gustav, they look fantastic, but CRAP! I got 3x4 switches, and I needed 4x3! :(
Title: SSL HELP THREAD!!!
Post by: bubba_b on December 02, 2004, 02:27:02 PM
I hooked up my transformer. I have the same type as tubejay has and I hooked it up like this (per this forum):

Then I measured voltage between blue and green. It's supposed to be approx. 30VAC. I measured about 38-39VAC. Is this acceptable? How close should it be? Seeing as how there's nothing else in the box except the IEC and trafo, this should be pretty easy to troubleshoot.  :grin:
Title: SSL HELP THREAD!!!
Post by: Ian MacGregor on December 02, 2004, 03:00:33 PM
Is the measurement you made RMS or peak? Also, consider that the mains voltage can vary quite a bit (~30%). Also, the voltage you measured is the no load voltage, which will be higher than the voltage under load (This is probably the main reason why you are seeing a high secondary voltage). I would build the board and give it a go.

Ian
Title: SSL HELP THREAD!!!
Post by: bubba_b on December 02, 2004, 03:07:40 PM
It was RMS. I didn't think it was faulty, just wanted to double check. Thanks, Ian. I'll be back with updates, etc. once I get the board going.

BTW...this place is great. You guys are so helpful. If I could, I'd have my grandma make you all cookies.
Title: SSL HELP THREAD!!!
Post by: tmbg on December 02, 2004, 03:30:03 PM
My first GSSL is stuffed, waiting on the power transformer.  Bought a box and an edge meter from Ack today... This meter just happened to be their only edge meter in the place, and happened to be a 1mA DC, and is in a box that suggests it's been on the shelf for 30 years :P

Tonight I'll likely handle the drilling and such fun stuff, maybe make wiring harnesses for the control board and the in/out jacks.

Also I bought some teeny 12VDC light bulbs, thinking I would drill (or melt) a little hole in the back of the meter housing to illuminate it.  Will a 12vdc filament lightbulb introduce any noise into the power supply?  I guess I probably shouldn't run it off the regulated 12V, since a) it may disturb the control voltages, and b) the bulb draws 60mA, and 78L12 only provides 100mA if I remember correctly...

So, is it kosher to use the rectified and unregulated 15+ volts pre-7815, and if so, do I need a resistor to make up the voltage difference?  Will that affect my power?
Title: SSL HELP THREAD!!!
Post by: Greg on December 02, 2004, 03:42:26 PM
Exactly, use the rectified, but unregulated VDC for the bulb, with the appropriate series resistor.
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on December 02, 2004, 04:46:04 PM
hi guys....

I have two comps in a 1 case.. 1 of the comps when I put an input to the left XLR and an output on the right XLR it passes audio whilst the other one does not.... has anyone got the same problem?  

both compressors, compress and work well but I'm curious to see whetehr this is normal or not?


thanks
Title: SSL HELP THREAD!!!
Post by: gyraf on December 03, 2004, 04:01:52 AM
Keith,

You'll need to explain that again...?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: giobinein on December 03, 2004, 04:08:40 AM
I'm bulding the SSL clone (thnaks for the project gyraf !!!) but here in Italy I can find only the THAT2180LC; is good or bad for this project ??
 :oops:  :oops: Thanks !!
Title: SSL HELP THREAD!!!
Post by: gyraf on December 03, 2004, 04:19:13 AM
Giobinein,

They'll work fine. They're much better than the old DBX2150 anyway.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: giobinein on December 03, 2004, 04:24:33 AM
thanks gyraf  :thumb:
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on December 03, 2004, 05:23:43 AM
ok gyraf..

its a bit difficult to explain...I am using 1 input xlr wire and 1 output xlr wire for testing single channels.

On the first compressor when I connect the left input xlr and right output xlr audio passes...  :roll:

on the second compressor I have to connect left input XLR to left output XLR for audio to pass if I do the above configuration audio won't pass.

I'm not sure which one is behaving as normal.

Hope this is a bit clearer.

cheers
Title: SSL HELP THREAD!!!
Post by: gyraf on December 03, 2004, 06:57:23 AM
You have probably just switched the two channels on either input or output XLR's?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on December 03, 2004, 07:58:57 AM
hi jakob...

I thought of that too...but both outpus have audio in them when either the left or the right input has a signal in.


any ideas?  :?
Title: SSL HELP THREAD!!!
Post by: tubejay on December 03, 2004, 09:03:16 AM
Did you do a continuity check between the pins on your outputs and inputs to see if you've got a short somewhere?  Sounds like it could be short.  I'd do a continuity cross check between each and every pin (and every combination) on the ins and outs to see if that's the case.  Also check the top side of your PCB to make sure a stray little wire didn't work it's way over to short out to the other side.
Title: SSL HELP THREAD!!!
Post by: Emperor Tomato Ketchup on December 04, 2004, 01:37:06 AM
I think I might have discovered the source of my distortion.  After reading the data sheets from THAT corp, I decided to check for AC in my sidechain.  I found AC on the CV inputs of the signal VCA's that was directly proportional to the distortion I was hearing.  When set at low attack and release settings, the AC went up (from 5 to 10 mV) and the distortion went up.  The AC was also higher for lower frequency sine wave inputs.

Of course, the AC throughout the side-chain was larger or smaller, depending on where I measured.  I traced it all the way up to the TL074 opamp.  I am getting:

0.0 VAC at "A"
0.96 VAC at "B"
0.022 VAC at "C"
0.015 VAC at "D"

I seem to remember reading in the Meta that the TL074 section here is a rectifier?  I assume that I shouldn't be seeing any AC at point "C", or is 22mV considered insignificant?  I'm still a newbie, and I dont fully understand what's happening in this section of the sidechain with the opamps and diodes.  Any suggestions would be appreciated.

-Chris
Title: SSL HELP THREAD!!!
Post by: BackHand on December 04, 2004, 10:41:36 AM
Hello!

I just built a SSL compressor using the Gyraf Audio kitt.
I hooked it up for the first time now and got some problems :sad:
None of the compressor controlls (attack, relase, threshold and ratio) makes any diffirance? And the meter is dead.. :sad:
But is recieves audio signals and sends them out, the makeup gain and the Bypass switch is the only things thats working. One more thing, theres is about 5 dB louder signal in the right output than the left?
What could disconnect the meter and all the compressor controlls (the bypass seems to be working since the make up gain disconnects when a swich on bypass) ?!
Totally lost... :sad:  :?:  :!:
Title: SSL HELP THREAD!!!
Post by: tubejay on December 04, 2004, 11:27:21 AM
BackHand,

I had a couple similar problems.  Here's some ideas that might help:

For the 5db down in one channel, check around your 5532's on the inputs and outputs.  Make sure you don't have a solder bridge between pins 1 and 2, or 2 and 3.  If you do, it will be down about five dB in one channel.

I'm not sure why your compressor controls wouldn't work.  When you take the unit out of bypass, does the meter slam all the way to the top of the scale, or does it just do nothing.  When you take it out of bypass, does any sound come out, or does it just sound the same as when it's bypassed?  Are you positive that you've got the bypass switch wired up correctly?  Sometimes it helps to remove the bypass switch and just hard wire it into compression mode, to make sure that it's not the switch.  Is it possible that there would be a solder bridge between the meter input and one of the pins that connect the controls board to the main pcb?

In the end what helped me troubleshoot my problem the best was to take a look at the pcb etch .pdf file, and double check to make sure that you didn't accidentally bridge any points that weren't intended to be bridged.  That's how I found the little piece of solder on my 5532 that was causing it to be down about 5db in one channel.  Sometimes it's hard to tell on these little pcbs if something should be bridged, or should not.  It's a really easy thing to miss.

Just keep searching, eventually you'll find the problems if you're persistent.

Jay
Title: SSL HELP THREAD!!!
Post by: tubejay on December 04, 2004, 11:36:13 AM
Backhand,

I just read on one of TMBG's posts that his meter wasn't working because he had it wired backwards.  That's another possibility!
Title: SSL HELP THREAD!!!
Post by: bubba_b on December 07, 2004, 06:00:01 PM
Quote from: "BackHand"

I just built a SSL compressor using the Gyraf Audio kitt.
I hooked it up for the first time now and got some problems :sad:
None of the compressor controlls (attack, relase, threshold and ratio) makes any diffirance? And the meter is dead.. :sad:
But is recieves audio signals and sends them out, the makeup gain and the Bypass switch is the only things thats working. One more thing, theres is about 5 dB louder signal in the right output than the left?
What could disconnect the meter and all the compressor controlls (the bypass seems to be working since the make up gain disconnects when a swich on bypass) ?!
Totally lost... :sad:  :?:  :!:


I'm in the exact same boat. Identical problems. Anyone know what we're doing wrong here?
Title: SSL HELP THREAD!!!
Post by: tmbg on December 07, 2004, 06:11:56 PM
bypass wired correctly?

There's two bypasses, a SPST makeup gain defeat, and a SPDT compressor bypass.

I have mine wired to a 4PDT pushbutton latching switch, with an LED on one pole.  Works great :)
Title: SSL HELP THREAD!!!
Post by: bubba_b on December 07, 2004, 06:20:10 PM
Bypass is a simple 2 pole switch and works fine. defeats make-up and lets dry signal through. When not engaged, make-up works, but that's all that does. I can't see any pins crossed on the 5532's, but when I press on the 5532 for the left output, or on the .1uF cap next to it, I get a horrible crackling.
Title: SSL HELP THREAD!!!
Post by: bubba_b on December 08, 2004, 01:05:07 AM
tmbg - I found it. You were right. Stupid me had the bypass switch hooked up to the make-up defeat, but the compressor in/out connects on the PCB were open. Hooked up the switch in there and bingo! Everything's dandy in candyland.

BackHand - If you still haven't fixed yours yet, check that out and see if that's the problem. It's the 3 PCB solder points on the right side of the control board labeled "com", "on" and "off".
Title: SSL HELP THREAD!!!
Post by: Emperor Tomato Ketchup on December 08, 2004, 08:49:08 AM
No takers on my AC voltage issue?  I checked and rechecked my soldering, components, and wiring.  I did forward and reverse diode tests on all the diodes in my sidechain and they all seem OK and are installed with the correct polarity.

Can someone with a succesful GSSL build run a sine wave through it and see if they get any AC at points "B", "C", or "D" on the schematic?  I'm still not sure if this is my problem, but it makes sense to me that if the CV input of the audio VCA's are seeing AC, then they would cause flutter, which might sound like distortion.  Sort of like pulling a fader up and down at 60 cycles/second.

BTW, I'm using the DBX c1252h2 VCA's.

Thanks,
Chris
Title: SSL HELP THREAD!!!
Post by: gyraf on December 08, 2004, 09:06:04 AM
Chris,

AC measurements on the sidechain voltages are not really telling us anything - they're entirely dependent on sidechain timing setting and input signal frequency

And off course you'll get distortion when there's a relatively large AC component on your SC voltage - that happens on all compressors, and is a result of too fast a timing applied on too low-frequent a signal source.

This is a compromise needed for all compression.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Emperor Tomato Ketchup on December 08, 2004, 10:37:29 AM
Thanks Jakob.  I'm glad I didn't get caught up on the AC then.  The symptoms you described are exactly my problem, with more distortion at low frequencies and short attack and release.  I still must have done something wrong though, because even though there is less, there is still noticible distortion at long attack/release for full range material (like a mix).  I compared the sound quality side by side to my friend's Smart C2 and there was no distortion present in the C2 at comparable settings.  In short, I wouldn't use my GSSL on a mix yet.  I guess I will actually try to measure my time constants in my side chain to see what is happening.  Maybe I can convince my friend to loan me his C2 as a reference.

Do you think this distortion difference between my GSSL and the C2 might have anything to do with the DBX c1252h2 VCA's I used?

BTW, this is my third DIY project, after a G7 and a G9 (which both went smoothly).  Despite my lack of success on the GSSL, I am learning more on this project.  I appreciate all the feedback from everyone.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 08, 2004, 11:11:23 AM
Quote from: "Emperor-TK"

Do you think this distortion difference between my GSSL and the C2 might have anything to do with the DBX c1252h2 VCA's I used?


No. You clearly have a sidechain problem, if working-distortion is audibly annoying at decent settings.

It would be best to trace the sidechain signal with a scope.

- Check your full-wave sidechain rectifier and threshold diode for wrong-oriented diodes.

- Check value and polarity of your timing caps (the 0.47uF tantalums)

- Check values of sidechain timing resistors.

Jakob E.
Title: power
Post by: EEMO1 on December 10, 2004, 08:08:27 AM
hey,

 i've stuffed my boards. now's the time to wire things up. im not sure how to wire the rotary on/off switch (4x3, programmed to 2) im not sure about this one.

 any help is appreciated,

 eero
Title: SSL HELP THREAD!!!
Post by: Greg on December 13, 2004, 02:58:18 PM
EEM01:

I'm not sure if you posted this before or after our PMs... were you able to get the ON/OFF switch working?

Just as a side:
I think I'm going to label the BYPASS switch as the ROCK knob when I get my engraving done. I put my GSSL on my main mix buss the other day just to see what it did, and compressed at 2:1, maybe 1-3dB with auto release and middle attack position. I kept switching the BYPASS back and forth and thinking to myself... this mix rocks, this mix doesn't rock, this mix rocks, this mix doesn't rock. The more and more I use this comp the more I like it (at least on certain things, of course)... I'm not a fan on vocals.
Title: hey
Post by: EEMO1 on December 14, 2004, 07:58:53 AM
hey,

 yeah i got the pms. thanks.

 the on/off switch worked like a charm. first try and everything. now i just have to wait for the 2u rack and finish the unit. can't wait to get it finished. i got songs waiting...
Title: SSL HELP THREAD!!!
Post by: wiz1der on December 14, 2004, 11:40:59 AM
YO GREG!!

    Don't forget me on that .fpd

Thanks man, you have been a BIG help.
Title: SSL HELP THREAD!!!
Post by: Greg on December 14, 2004, 01:24:54 PM
Yea... I really need to get it finished. I'm distracted right now because I'm sourcing parts to build a pair of API 312s. I'm sure I could finalize the .fpd in a couple hours. I'll get it done soon.
Title: +6 dB in bypass...
Post by: PabloJn on December 15, 2004, 10:17:48 AM
Hello everybody! I finish my first SSL comp and I'm testing it...

I've a +6dB gain in bypass position... this is not ok I think ??!
All voltage (+/-15 +/-12) are ok
I made some try and replacing the NE5532 (output stage) I found one that doesn't make the +6 dB gain... I'm boght some other 5532 but I didn't try them yet...

Does anyone can give me some help???

--Another question.... the pcb rev 7 & schematic rev 5 are a little different in input and output connections?

i.e.:  in the pcb the L+ go through two parallel caps and a 22K res into the 5534 pin 3 (+IN)  but in the schematic the L- go into the pin 3...  

Is it true?

please help....
Title: SSL HELP THREAD!!!
Post by: radiance on December 15, 2004, 10:50:06 AM
6 db gain in bypass position is O.K. I think.

On the SSL schematic (rev #5) it sais:

"*15K  Use 27K for unity gain when running unbalanced" so that for me explains the extra gain. I'm not sure it was 6db though...
Title: SSL HELP THREAD!!!
Post by: PabloJn on December 15, 2004, 11:26:07 AM
Quote from: "radiance"
6 db gain in bypass position is O.K. I think.

On the SSL schematic (rev #5) it sais:

"*15K  Use 27K for unity gain when running unbalanced" so that for me explains the extra gain. I'm not sure it was 6db though...



thank you. I'm working balanced, but 6 db between bal and unbal could be...


what about the input connection? this image can explain what I would say...
(http://xoomer.virgilio.it/pablojn/sch_vs_pcb.gif)

the "red" path is the same in the pcb and schematic but in the pcb the connection is with the COLD pin (-) and in the schematic is with the HOT pin (+)
Title: SSL HELP THREAD!!!
Post by: radiance on December 16, 2004, 06:15:57 PM
I don't see the image PabloJn. Unlike other forums you have to upload your images to a server and post a link.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 17, 2004, 03:19:38 AM
Pablo,

Don't worry about that - it's a minor schematic error.

The PCB's are known working.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: thedug on December 17, 2004, 08:44:55 AM
My ssl is cose to working. Only the left ch. is acting funny.
It pretty much has 0 output.

The left ch. 5534 show unity gain. 1.3volts in and 1.3 volts out.
I swapped 5534s and teh problem stayed on the left channel.

What is wierd is that the meter reads the same with the same signal on either input.

I didn't really see any signal on the 5532 on ch. 1

d./
Title: SSL HELP THREAD!!!
Post by: gyraf on December 17, 2004, 09:22:44 AM
Quote from: "thedug"
What is wierd is that the meter reads the same with the same signal on either input.
 


Which means that the input circuits and the sidechain are working well.

Your problem can be found in the vca or output section in the silent channel.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: thedug on December 17, 2004, 09:56:47 AM
So I shouldn't get hung up on the unity gain on the 5534?

Should I keep tracking the signal through the "signal path" part?

d./
Title: SSL HELP THREAD!!!
Post by: radiance on December 17, 2004, 03:51:25 PM
My second SSL clone is passing audio, but way too loud, to the point that it distorts. It is not compressing but the make up pot seems to work (a few db extra gain, that's all) and the threshold seems to do the same thing as the make up pot. In bypass mode the ssl still distorts but both the make up and threshold pot don't affect the volume (that's a good thing I suppose..).

I did check the following:
When both VCA's are removed and pin 1 is wired to pin 8 the ssl passes audio OK (it's not distorting) so I guess the input and output sections are OK.

I swapped all chips to my working ssl and they all seem to be OK.

All diodes are working (desoldered and tested them) and put in the right way.

So far I can't find any short's.

Meassured almost all resistors but could not find anything wrong.

I'm really clueless about what is wrong.
Thanks in advance.
Title: SSL HELP THREAD!!!
Post by: thedug on December 18, 2004, 01:55:38 AM
Ok....

After much probing with my oscope, I couldn't really understand this...

I decided to swap the vcas to see what would happen. Well the problem with 0 output followed the vca. So.. it appears that I have a vca.

But upon tracing the circuit I found a few interesting things.

1) the 1k signal I was sending in went through the input stage to teh 15k resister, but then on the other side of the 15k at pin 1 of the 2150, it disappeared!
2) the signal didn't show on any pins of the 5532 until pin 7, the output!

Last, I had some more vcas that I had ordered for building other units, these are the 2180s I seemed to remember that you didn't want to mismatch the channel vca so I put in 2 2180s and left the sidechain a 2150. Is this ok?

BTW: The unit seems to work. If I turn the threshold all the way down, the VU pegs and I get a saw wave. Does this sound right?

d./
Title: SSL HELP THREAD!!!
Post by: thedug on December 18, 2004, 02:03:35 AM
Quote from: "gyraf"


When using the trimmerless 2180, simply leave out the trimmers (and possibly the two 1M resistors between trimmer and VCA)



Hey, I just poped in 2180LB, can I remove the distortion trim too?

Looks like just taking the 1M resister out would disable it. Is it advised to take the trimmer out too?


Also, I just found this thread on the pricing, http://www.groupdiy.com/index.php?topic=379&postdays=0&postorder=asc&highlight=2180&start=30

The LA is quite a bit more expensive than teh LB. Is it preferable?
Title: SSL HELP THREAD!!!
Post by: gyraf on December 18, 2004, 03:57:56 AM
Quote from: "thedug"
..1) the 1k signal I was sending in went through the input stage to teh 15k resister, but then on the other side of the 15k at pin 1 of the 2150, it disappeared!
2) the signal didn't show on any pins of the 5532 until pin 7, the output!


The 2150-series VCA's are current-in current-out devices. No voltage change on it's input and output termonals when it's working correctly


Quote
BTW: The unit seems to work. If I turn the threshold all the way down, the VU pegs and I get a saw wave. Does this sound right?


No. Check for shorts to pot wiper either on the main or the control board.

Quote from: "thedug"
Hey, I just poped in 2180LB, can I remove the distortion trim too? Looks like just taking the 1M resister out would disable it. Is it advised to take the trimmer out too?


No need to remove the trimmer, just the 1M resistor.

Quote
The LA is quite a bit more expensive than teh LB. Is it preferable?


Not much. Depends on your ambitions. I get no audible difference - but inb theory it should be better.
Title: SSL HELP THREAD!!!
Post by: thedug on December 18, 2004, 11:03:29 AM
Quote from: "gyraf"

The 2150-series VCA's are current-in current-out devices. No voltage change on it's input and output termonals when it's working correctly


So is there a way to "trace" through "virtual ground" stuff? Is there a way to know this? Cuz I was sure something was wrong last night.. ;P I.E. What distinguishes that something is a current-in current-out device

Quote from: "gyraf"

No. Check for shorts to pot wiper either on the main or the control board.

Actually, no shorts, but I did realize that I had the release set to position 6, only letting the release be pos. 1-5 got rid of the saw. Now, the pegged meter is prolly cuz it is a VU meter... See my next post about sourcing a VU that will work. :P

Also, it was really mind opening to watch the oscope as I changed the threshold with slow release/attack. Pretty cool. :P

Also, is it ok to use a 2180 in the audio section and a 2150 in the sidechain, or should I try to make them all the same?
Title: VU Meter
Post by: thedug on December 18, 2004, 11:40:21 AM
The vu meter I have was sourced by a friend, it is the sifam AL19, which is a vu meter. Could this be causing my problems?

The thing is too big anyway, would this meter work?
Mouser Part: 541-ME-DMA-001

NRG's scale looks nice. Does anybody have a scale for the rectangular style vu?
Title: SSL HELP THREAD!!!
Post by: radiance on December 18, 2004, 12:43:27 PM
Quote from: "radiance"
My second SSL clone is passing audio, but way too loud, to the point that it distorts. It is not compressing but the make up pot seems to work (a few db extra gain, that's all) and the threshold seems to do the same thing as the make up pot. In bypass mode the ssl still distorts but both the make up and threshold pot don't affect the volume (that's a good thing I suppose..).

I did check the following:
When both VCA's are removed and pin 1 is wired to pin 8 the ssl passes audio OK (it's not distorting) so I guess the input and output sections are OK.

I swapped all chips to my working ssl and they all seem to be OK.

All diodes are working (desoldered and tested them) and put in the right way.

So far I can't find any short's.

Meassured almost all resistors but could not find anything wrong.

I'm really clueless about what is wrong.
Thanks in advance.


I forgot to mention that the +15v/-15v and +12v/-12v are all there so the power suply seems to be OK.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 18, 2004, 01:05:39 PM
Radiance,

Try tracing the signal through the sidechain - and look out for wrong-value resistors..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: radiance on December 18, 2004, 06:52:51 PM
I meassured all the resistors in the sidechain and their values where OK.

I also meassured the pins off both the TL072 and the TL074 for DC  with no signal present and in bypass mode.
I got these values:

TL072

Pin 1=3,4v DC
Pin 7=4,1v DC


TL074

Pin 1=0,177v DC
Pin 7=0v DC
Pin 8=0,0013v DC
Pin 14=0,37v DC

At point C in the circuit I meassured 0,039v DC.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 19, 2004, 03:59:54 AM
Rad,

Look through - and try to understand - the schematic. There's a circuit description on the gyraf page.

This will help you a lot with troubleshooting

TL072 pin1 changes with threshold + signal level
TLo72 pin7 changes with makeup + signal level

TL074 pin14 changes with ratio + signal level

Jakob E.
Title: SSL HELP THREAD!!!
Post by: radiance on December 19, 2004, 08:28:35 AM
Thanks Jakob, and I found the problem.
It happened to be a short between pin 2 and 6 of the TL072.
What I did not understand was why I was getting DC at pin 7 from the TL072 while the unit was in bypass mode and there was no make up bridge. I starded to meassure continuity between the pins from the TL072 and found the problem.
This nearly drove me nuts so I'm very happy the problem is solved.
During the proces I fried one VCA but I really don't care right now.

Thanks!
Title: SSL HELP THREAD!!!
Post by: gyraf on December 19, 2004, 09:01:35 AM
I'm happy we got that sorted...!

 :thumb:

Jakob E.
Title: SSL HELP THREAD!!!
Post by: thedug on December 19, 2004, 09:41:39 AM
Is it ok to us 2180s in the audio section and a 2150 in the sidechain?

If so, are there any drawbacks to doing this?
Title: SSL HELP THREAD!!!
Post by: gyraf on December 19, 2004, 09:42:52 AM
Yes it is.

- I think we've already answered this earlier..?

Jakob E.
Title: phase problems...
Post by: PabloJn on December 20, 2004, 01:22:55 PM
about the +/- input connection difference between schematic and pcb ...

Quote from: "gyraf"
Pablo,

Don't worry about that - it's a minor schematic error.

The PCB's are known working.

Jakob E.


Are you sure the error is not in the pcb :?:

my ssl clone is phase reversed if I connect the inputs as in the pcb is marked...

if I sum the dry input with the signal throught the compressor in bypass I have a null signal...


I have another problem: my ssl clone gain up a +6 db in bypass.
I'm working balanced.

Is it ok :?:
Title: SSL HELP THREAD!!!
Post by: gyraf on December 21, 2004, 02:28:54 AM
Yes, I'm sure there's not an error on the pcb.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: keithcamilleri on December 21, 2004, 05:00:37 AM
hi guys,

has anyone got or had a problem with an ssl phasing? One of my ssls is phasing, I've redone the exact same wiring as the one working ok but the problem is still there. Was wondering if anyone had a problem like this... :roll:


cheers
Title: SSL HELP THREAD!!!
Post by: gyraf on December 21, 2004, 05:22:30 AM
Check and Recheck your in/out wireing.

There's nothing in there that can affect phase other than this.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: radiance on December 25, 2004, 08:54:39 AM
Trying to understand the schematics of the SSL clone I came across two 10R resistors just before the 79/78L12 voltage reg.'s.
What purpose do they serve? Are this two resistors for a slight voltage drop? I meassured the DC before and after these resistors and got 43v DC before and 43v DC after the resistor so that's no voltage drop (or I have done something wrong obviously, the clone is working though).

Also, I have this 12v meter light that I want to use. Can I just at a resistor in front to make the voltage drop? (I'm tapping the power before the bridge rectefier as described in Jakob's SSL scem.)
Title: SSL HELP THREAD!!!
Post by: Rob Flinn on December 25, 2004, 08:59:21 AM
Quote
I came across two 10R resistors just before the 79/78L12 voltage reg.'s.


I think these provide a bit of current limiting protection.
I fyou look at this:
http://www.recording.org/users/kev/Project2.htm
Scroll down to the PSU bit & they have a similar thing, which Kev has explained a bit.
Title: SSL HELP THREAD!!!
Post by: andre tchmil on December 25, 2004, 04:04:19 PM
I'm using myy ssl clone for a few months now . Works smooth etc.
But I still have a slight problem with the threshold setting.
When I feed in Program material, let's say - 8dB out from my convertors,
I can hardly move  the threshold pot down CCW before the Compression kicks in immeditaley for a +- 4 dB compression at ratio 2.
Is this normal, or did I overlooked some parts on the PCB ?
Title: SSL HELP THREAD!!!
Post by: radiance on December 25, 2004, 07:15:21 PM
Thanks Rob!
I forgot a little about Kev's site. I should check it more often because it's very usfull.
Title: hey
Post by: EEMO1 on December 26, 2004, 02:22:24 PM
hey.

 i got my ssl working. compresses, bypass works and even the meter works fine.

 one thing though,  volume on the other channel is much more quiet. any ideas?

 -eero
Title: yeah!
Post by: EEMO1 on December 28, 2004, 04:10:41 PM
success! after some rewiring and rewiring again it works. seems like even the power grounding (i did it a little wrong) affected it working at all... i suck at metal work but for my first diy, im pretty satisfied. i had all the problems described here. hanging up, other channel much quieter... all problems cause of the wiring. i pleased to have a working compressor.

 the release has to be five positions right?

 -eero
Title: SSL HELP THREAD!!!
Post by: Kev on December 28, 2004, 04:30:28 PM
Quote from: "radiance"
I forgot a little about Kev's site. I should check it more often because it's very usfull.


make the most of it because it will go soon
people stopped looking at it so there is no point leaving it up

a fair bit will move to my new place but there is much stuff that just won't

change does happen whether I like it or not ...  :sad:
Title: SSL HELP THREAD!!!
Post by: Greg on December 29, 2004, 01:45:36 PM
I ordered a couple of B* meters a couple days ago from dbm Pro Audio. I just got a call from them saying they won't have those meters in stock for a couple of months... just wanted to give people here in the states that bit of info.

I'm thinking about using an edgewise meter that can be ordered from Mouser instead.
Title: SSL HELP THREAD!!!
Post by: wiz1der on December 29, 2004, 02:26:30 PM
So that means a whole different .fpd because of a different meter shape huh...

I was planning on building two at the same time, but only have one b* meter.
Title: SSL HELP THREAD!!!
Post by: andre tchmil on December 29, 2004, 03:44:05 PM
Euh pardon me,
Anyone ? :oops:
Title: SSL HELP THREAD!!!
Post by: RemcoV on December 29, 2004, 03:55:26 PM
Andre:

I found the SSL to be very sensitive as standard, and kicking in quickly aswell.
I solved this with adding an extra resistor with the bottom threshold line (the one that goes to the potmeter from the board) i used i think 56k and that limits the threshold range a bit, but it makes it way more usefull (to my opinion atleast)

hope it helps!
Remco
Title: Re: yeah!
Post by: gyraf on December 30, 2004, 06:56:36 AM
Quote from: "EEMO1"
the release has to be five positions right?


Yes!
Title: SSL HELP THREAD!!!
Post by: Twin-x on December 30, 2004, 07:54:37 AM
(http://twin-x.com/troep/sidechain.gif)

Hi,

I found this somewhere (i think it's from steffens site).
Since i am a bit noobish i would like to know to what pins or paths i must connect the to "control amp" and from "input buffer" to on the gyraf ssl PCB. Is it an addition or is it to replace the current sidechain in the gyraf schematic?

If i am not allowed to post this picture i will remove it at once.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 30, 2004, 08:16:13 AM
Twin,

It's probably an addition, that goes between the two input debalancers and the existing sidechain.

But I'd recommend that you build the Clone as-is, ans then later modify if you're not satisfied with the results..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Twin-x on December 30, 2004, 09:08:11 AM
@ Gyraf
I am building it for a friend that has no soldering or electronic skills.
He wanted the sidechain no matter what (for the ducking effect?).
Title: Output level mismatch
Post by: skrasms on December 31, 2004, 10:57:41 AM
I finally got around to using my SSL clone on a mix instead of just in mono, and it turns out one side is about 6 db lower in output than the other. It doesn't seem to be getting 6db more compression, just that the final output is that much lower. I say that because when I kick one side up 6db in Cubase the sides look and sound balanced out.

Any ideas of what might be causing this?
Title: SSL HELP THREAD!!!
Post by: gyraf on January 02, 2005, 05:11:32 AM
Wireing problems? Broken balancing?

Check that you have output at both + and - outputs (xlr pin2 and pin3)

Other than that - wrong resistor value somewhere?

Jakob E.
Title: fixed?
Post by: skrasms on January 03, 2005, 12:33:51 AM
After not using it for a day, it's working fine. I probably just had something configured wrong on the output bus in Cubase.

Thanks for the tips though!
Title: SSL HELP THREAD!!!
Post by: Greg on January 10, 2005, 08:13:04 AM
For those who have used the Jewell Modutec edgewise meter from Mouser (Part # 541-ME-DMA-001), is there a light kit associated with this meter? I didn't see a reference or anything like that in the Mouser catalog.

Thanks.
Title: SSL HELP THREAD!!!
Post by: tubemonkey35 on January 10, 2005, 10:33:39 AM
I just got the Jewell meter too, and looking at how does it mount to the chasis?

I think svart posted somwhere about opening it up and putting a light inside.
Title: SSL HELP THREAD!!!
Post by: Greg on January 10, 2005, 10:43:23 AM
Yea, I'm thinking that I could just crack it open and get some LEDs in there.

I'll have to see about mounting when I get it.
Title: SSL HELP THREAD!!!
Post by: tubemonkey35 on January 10, 2005, 10:57:30 AM
Ther meter came with these two brass looking bezel frames that have little teeth on the left and right sides.
Title: SSL HELP THREAD!!!
Post by: tubemonkey35 on January 10, 2005, 10:59:15 AM
ok, here's my lame question:

What guage wire is best for the GSSL and am I correct that it should be stranded? Any favorite brands?
Title: SSL HELP THREAD!!!
Post by: gyraf on January 10, 2005, 11:22:12 AM
Dosen't matter. Use some that is easy to work with.
Title: SSL HELP THREAD!!!
Post by: Greg on January 12, 2005, 03:31:27 PM
Quote from: "tubemonkey35"
I just got the Jewell meter too, and looking at how does it mount to the chasis?.


I just got my meter in today. So make the cutout (which really has to be exact since the edge is clear), then slip the brass piece on the backside of the faceplate, and the teeth grip onto the plastic and basically forms a pressure fit. I tested it out the cardboard it came in and it holds snug.
Title: SSL HELP THREAD!!!
Post by: wiz1der on January 12, 2005, 03:48:45 PM
hey just got mine in too, it seems that it would work mounted upside down, to get a right to left reading?

There is clear tape holding it together, but yes, take the tape off, and it slides open so you can hot glue a light inside.

I just need to figure out a way to make a nice scale.
Title: 15v 12v
Post by: Brizco on January 19, 2005, 03:25:40 PM
hello to everyvody @ this healp thread


my problem is: i dont get these 15v and 12v

- i use a dagnall 18v trafo (measured output 20v)
- i allready checked the bridge rectifier
- i replaced new 7815 and 7915
- i checked soldering on pcb
- i replaced the 1000u caps
- i measured components during assembling


... but no 15v!!!

what can have i forgotten to check?
where could the problem be?

thanks for your help!
Title: SSL HELP THREAD!!!
Post by: gyraf on January 20, 2005, 05:56:31 AM
Briz,

Check that you have the right voltage at the 1000uF caps, going into the 7815 regulator. Have you read this thread from the start? IIRC, there are similar problems solved in the past.

Jakob E.
Title: voltage?
Post by: Brizco on January 20, 2005, 10:55:55 AM
ive read it, but maybe i havent understood it, becuase of my bad english :sad:

what voltage should there be?
wich points of the 7815?

thank you very much!
Title: SSL HELP THREAD!!!
Post by: gyraf on January 20, 2005, 11:05:50 AM
Briz,

Find a data sheet for the 7815, and try understanding what the component does. This will explain all, I think

Google, and you'll find plenty of pages like this:
http://www.ee.latrobe.edu.au/internal/workshop/datasheet.html

that points to the datasheet:
http://www.ee.latrobe.edu.au/internal/workshop/store/pdf/7815.pdf

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dukasound on January 20, 2005, 11:40:05 AM
Hi
I found some different specifications about mains transformer.
What is enough VA?
Thanks in advance
Duka
Title: thanks
Post by: Brizco on January 20, 2005, 11:44:28 AM
thank you jakob, for all your help!

you even help such newbies like me! i will read it, but cant promise if i understand it.

thank you.
Title: success
Post by: Brizco on January 20, 2005, 01:26:38 PM
after reading the specification and measuring the voltages it was clear:
i had to check the pcb again!! and i found one tiny short!!

shame on me! :oops:

the unit has now the 15 and 12 volts!

thanks for your help!!
Title: SSL HELP THREAD!!!
Post by: The Landlord is Dead on January 20, 2005, 08:11:53 PM
Just finished my SSL and everything is working but the meter. I'm also using the jewel/modutec meter from Mouser. I've lost the hookup pamphlet that came with it, maybe I'm missing something. I hooked up the - to the - minus on the board and the + with a 2k resistor to board. How did you guys hook it up to the control PCB?
Title: SSL HELP THREAD!!!
Post by: xsou on January 20, 2005, 10:18:50 PM
Hello,

I've been looking at this very helpful forum (you guys all rock!) for months berfore making my SSL clone.And today I can announce that I've finished the project but need your help!
Her's the situation:
when I switch on the clone, the meter begins trembling around the same value (Thrsld set arroud/below 0dB), and this happens with or without incoming audio signal.
I've tried to find the problem by changing the voltage regulators, checking components values, shortcuts, if I had the right voltages (I get +14,91V & -14,95V ; +12,15V & -11,87V) but nothing changed...(maybe have I forgotten sthing!)
With audio signal incoming, it goes out, I can adjust the treshold and the makeup gain, but the meter does not moves as if audio modulates it (and I can't ear any compression).
I hope that you can understand my problem (excuse my english...) and try to help me solving it .

In advance thank you for your response,
Best regards,
Alex
Title: SSL HELP THREAD!!!
Post by: Hulk on January 21, 2005, 11:27:17 AM
I'm working on my first SSL - does it matter what direction I turn the IN4148 Silicon Diodes on the PCB??
Title: SSL HELP THREAD!!!
Post by: radiance on January 21, 2005, 11:41:45 AM
Quote from: "Hulk"
I'm working on my first SSL - does it matter what direction I turn the IN4148 Silicon Diodes on the PCB??


YES, it matters.

Check this (http://www.americanmicrosemi.com/tutorials/diode.htm) diode tutorial....
Title: SSL HELP THREAD!!!
Post by: Hulk on January 21, 2005, 11:55:20 AM
Thanks radiance just the help I needed!!
Title: SSL HELP THREAD!!!
Post by: tubejay on January 21, 2005, 12:01:36 PM
I just want to one last time warn against the Behringer meters.  THEY SUCK!!!  My second one went out on me last night!!!  AHHHHHHHHHHHHH!!!!!

I could have bought a nice vu for the amount I've spent on these things, and now I need to buy ANOTHER ONE!!!!  DAMN!!  Well, I think I'm going to have my front panel redone professionally now, and buy a good meter.

That said, I used my SSL comp as drum throw on kick and snare last night, and squashed the ever living pi$$ out of them.  It sounded so damn sweet in a rock mix.  They were smacky and loud without being harsh.  Really really smooth sounding.  This guy really makes drums pop in the mix in a really pleasing and utterly satisfying way.
Title: SSL HELP THREAD!!!
Post by: The Landlord is Dead on January 21, 2005, 09:07:00 PM
I think the needle in my meter is busted. The - lead of the meter seems to read fine with a voltmeter, a - few hundred mV at light compression settings too -5v or so for extreme compression. The voltage fluctuations move according to program material. I can't see anything physically wrong with it but the needle just won't budge.

I did open it up to switch out the meter scale to VU. I guess I banged something up accidentally? Any ideas or do I need to get myself another meter?
Title: SSL HELP THREAD!!!
Post by: tubejay on January 21, 2005, 09:32:06 PM
Does it bounce around if you shake your SSL compressor, or is it just totally stuck?  If doesn't even move when you shake it up, then something is probably wrong.  Have you tried to take off the front to see if it worked?  If the needle is rubbing against the front plastic piece or your scale, then it won't work.  I had that problem too.

These meters just suck.  They're really cheap.
Title: SSL HELP THREAD!!!
Post by: The Landlord is Dead on January 21, 2005, 10:27:29 PM
Just for the record, I'm using the "mouser 541-ME-DMA-001 dc milliammeter. edgewise". I can move the needle with my finger, feels fine, bounces back to it's set position. I've slid the top off so the needles been unobstructed, still no movement to the voltage fluctuations.
Title: SSL HELP THREAD!!!
Post by: Hulk on January 22, 2005, 04:19:49 AM
Could someone help me identifing these components for the SSL - I have tried the net but I didn't find anything:
(http://home1.stofanet.dk/jb65/SSL_Componenets_564x424.JPG)
1: The long arm is the posetive one right??

2: Don't know that one either :? (Is that one of the 25 100n 5mm 63V polyester capacitors(it says .1K 63 on top) for the -||- (.0) symbol on the PCB??

3: On these ceramic's it says: 10 then a little distance and then a 1 - they also have the letters MQK - are these the 10 ceramic's called (100p 100V 5% Monolithic) for the -||-(100p) symbol on the PCB??

4: On these ceramic's it says: 33 - are these the four 33p 100V 5% Monolithic for the -||-(33p) symbol on the PCB??

5: On these ceramic's it says: 220 and HQ J - are these the two 22p 100V 5% Monolithic for the -||-(22p) symbol on the PCB??

6: On this one it just says: 10 - is that the 10p 100V 5% Monolithic for the -||-(10p) symbol on the PCB??

Sorry for the stupid questions :roll:

I would be very greatfull if someone could help Thanks!!
Title: SSL HELP THREAD!!!
Post by: Mundox on January 22, 2005, 06:11:01 AM
Mouser meters, I think Modutecs, are not great either. They tend to be slow. I compared them to a meter I found in a surplustronics shop. It was a big 1ma edge wise meter that said TORR!
It's amazing the difference a simple meter makes in using the gear efficiently. :cool:
Title: SSL HELP THREAD!!!
Post by: Hulk on January 22, 2005, 09:26:05 AM
Quote from: "Hulk"
Could someone help me identifing these components for the SSL - I have tried the net but I didn't find anything:
(http://home1.stofanet.dk/jb65/SSL_Componenets_564x424.JPG)
1: The long arm is the posetive one right??

2: Don't know that one either :? (Is that one of the 25 100n 5mm 63V polyester capacitors(it says .1K 63 on top) for the -||- (.0) symbol on the PCB??

3: On these ceramic's it says: 10 then a little distance and then a 1 - they also have the letters MQK - are these the 10 ceramic's called (100p 100V 5% Monolithic) for the -||-(100p) symbol on the PCB??

4: On these ceramic's it says: 33 - are these the four 33p 100V 5% Monolithic for the -||-(33p) symbol on the PCB??

5: On these ceramic's it says: 220 and HQ J - are these the two 22p 100V 5% Monolithic for the -||-(22p) symbol on the PCB??

6: On this one it just says: 10 - is that the 10p 100V 5% Monolithic for the -||-(10p) symbol on the PCB??

Sorry for the stupid questions :roll:

I would be very greatfull if someone could help Thanks!!


Just a few more questions  :roll:

(http://home1.stofanet.dk/jb65/Print_566x425.JPG)

I have used "left over" wire from the resistors between the connections on the SSL PCB (black rings) - is that OK or do I need to use some kind of magic wire :green:
Within the yellow rings there are two different letters, one is called 100P the other is called 100p is there a difference between the capital letter P and the other p.??
Title: SSL HELP THREAD!!!
Post by: tubejay on January 22, 2005, 10:16:06 AM
I used resistor wires to jumper mine too...sounds fantastic.  I can't think of a reason why this would be bad.
Title: SSL HELP THREAD!!!
Post by: Greg on January 22, 2005, 11:10:45 AM
Quote from: "The Landlord is Dead"
Just for the record, I'm using the "mouser 541-ME-DMA-001 dc milliammeter. edgewise". I can move the needle with my finger, feels fine, bounces back to it's set position. I've slid the top off so the needles been unobstructed, still no movement to the voltage fluctuations.


I don't think meters will deflect at all to a voltage fluctuation. They deflect based on current... ie 1ma is full deflection. So I'm thinking your meter probably works.
Title: SSL HELP THREAD!!!
Post by: Hulk on January 22, 2005, 01:12:58 PM
Great tubejay - I'll just use the resistor wire!!

@Greg

I have used your SSL Component list to buy components - can you recognize any of the ceramic parts on the picture above??
Title: SSL HELP THREAD!!!
Post by: Rob Flinn on January 22, 2005, 02:26:17 PM
The 5 caps that are stuck together at the top look like tantalums, so it is probably likely that those are the 0.47uF since there are 5 of them.

The white square cap on the left looks like a polyester cap, & is similar to the ones that I used that were 100nF.  There are about 25 of these.

The rest of the caps look like ceramics.

If there is one that is more like a bead shape & looks like the tants at the top that is probaly the other tant 6.8uf if I recall corectly.
Title: SSL HELP THREAD!!!
Post by: gyraf on January 23, 2005, 05:34:52 AM
And yes, long leg is positive.
Title: +6 db in bypass
Post by: PabloJn on January 25, 2005, 06:10:14 PM
hello!!!

I'm still testing my ssl clone, now the phase is ok! but I have a +6 db in bypass position...

I'm working balanced and I made some tries shorting the pin 1 with the pin 3:

when I short pin 1&3 in the input connector nothing append...

when I short pin 1&3 in the output connector the +6db go away, and in&out have the same level  (bypass!!!)

I used the 15K resistor at the VCA input (the schematics says 15K for balanced; 27K for unbalanced, right?)

I apologize for my english... I wish anyone can understand and give me some help!!!!

thanks

Pablo
Title: SSL HELP THREAD!!!
Post by: gyraf on January 26, 2005, 04:31:31 AM
Pablo,

Don't short output pins when running unbalanced. This design dosen't like that. Just take your output signal from pins 1 and 2 (ground and +)

Jakob E.
Title: +6 dB problem
Post by: PabloJn on January 27, 2005, 07:33:41 PM
I found the solution of my problem in this topic

http://www.groupdiy.com/index.php?topic=1379&start=0&postdays=0&postorder=asc&highlight=

the right resistor for bal mode is 27K !?

I'm going to listen to my diy ssl clone!

thank for all, see you soon.
Pablo
Title: SSL HELP THREAD!!!
Post by: zboy2854 on January 27, 2005, 09:12:36 PM
A couple of basic newbie questions regarding grounding wiring.  Am I correct that when you say that the grounding should only be at one of the input XLRs, the wiring would be from the 0V input terminal on the PCB to pin1 on one of the input XLRs, and ALSO a wire going from pin1 to the bottom of the chassis?  Or is connecting the PCB terminal to input XLR pin1 enough without the need for a separate wire to the chassis itself?

Also, does this mean I leave pin1 unconnected on the other input XLR?  And do I connect both pins 1 from the output XLRs to the 0V output terminal on the PCB?  Thanks.   :?
Title: SSL HELP THREAD!!!
Post by: PabloJn on January 27, 2005, 09:43:42 PM
zboy, pins 1 of your in&out xlr are connected to the 0v (ground) of the pbc (look input&output connection)

if you connect the ground to the chassis you put the ground to earth (the chassis should be connected to earth), in my clone I made a switch that do this. It's like the earth lift switch. sometimes you need to put ground to earth but sometimes no...
Title: SSL HELP THREAD!!!
Post by: PabloJn on January 27, 2005, 10:04:15 PM
Quote from: "gyraf"
Pablo,

Don't worry about that - it's a minor schematic error.

The PCB's are known working.

Jakob E.


This is true!

I redrawn the schematic (just in&out sections) tracing the pcb rev7, I hope this can be usefull for someone...

Bye!

(http://groupdiy.twin-x.com/albums/userpics/10022/rev7%20schem_.jpg)

full size pic: http://groupdiy.twin-x.com/albums/userpics/10022/rev7%20schem.jpg
Title: My first GSSL - right channel distorts
Post by: rstreber on January 28, 2005, 01:47:35 AM
I just fired up my first SSL clone (also, after the great Bloo LA-2A, my first DIY project) and i've got a problem with the right channel. Everything works fine, all controls work, compression on the left channel sounds great, but the right channel has a much hotter output than the left and severely distorts in bypass or when the makeup gain is even slightly raised.  I'm going to try swapping out my 2180s and double check everything, but I just thought I'd see if anyone else has had this particular problem or could offer some suggestions.  

Thanks in advance!
Title: SSL HELP THREAD!!!
Post by: gyraf on January 28, 2005, 04:16:03 AM
Rstreber,

As always: Check for shorts on the pcb. Check resistor values.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: zboy2854 on January 28, 2005, 09:43:24 AM
Quote from: "PabloJn"
zboy, pins 1 of your in&out xlr are connected to the 0v (ground) of the pbc (look input&output connection)

if you connect the ground to the chassis you put the ground to earth (the chassis should be connected to earth), in my clone I made a switch that do this. It's like the earth lift switch. sometimes you need to put ground to earth but sometimes no...


Thanks for the response.  I'm still a little confused about connecting to the chassis itself.  Should I run a separate wire to the chassis, and if so, should I run it from the 0V terminal or from the XLR pin?
Title: SSL HELP THREAD!!!
Post by: Greg on January 28, 2005, 09:47:01 AM
Run a wire from the EARTH (GND), not Neutral, from the IEC to the chassis. Then connect that with pin 1 of the input (and output if you like) XLRs.
Title: SSL HELP THREAD!!!
Post by: Greg on January 28, 2005, 09:50:08 AM
Look Here:

GSSL Wiring Pic (http://members.cox.net/capstanrecording/GSSL/GSSL_Top)
Title: SSL HELP THREAD!!!
Post by: rstreber on January 28, 2005, 10:04:54 AM
Thanks for your response, Gyraf.  I tried swapping out 2180s, and that doesn't make a difference.  So far, all my resistor values are correct and I can't find any bad solder joints, but I'll triple check. I'm using one of Chef's PCBs, so it's very clean.

What's happening specifically is that it seems like the R channel is fine until the the audio goes above a certain level, and then it spikes and clips very hard.  For example, I was running stereo overheads through it and I can set it to a lower level where both channels sound fine until the the snare goes just beyond a certain point, and then the R channel output pops and is totally clipped.  The left channel is always fine.  Compression is happening on both channels, and when I set the level below this "threshold" where R channel clips, the two seem sides seem almost equivalent - R channel is just a little hotter.  When I put it in bypass or turn up the makeup gain to match the bypass level, R channel is totally clipped.  Again, all controls seem normal and the meter works fine. Could it be a bad cap or something?
Any thoughts? Thanks!
Title: SSL HELP THREAD!!!
Post by: zboy2854 on January 28, 2005, 10:05:36 AM
Great, thanks Greg!  :thumb:
Title: SSL HELP THREAD!!!
Post by: Hulk on January 28, 2005, 06:13:35 PM
I just got my toroid (Talema TRT30215, 230V-2x15V) transformer today but I'm having a hard time figuring out how to connect the wires because I don't have any information about the color of the wires - There's two yellow wires with extra insulation, one blue, one red, one green and one brown - I have found the specs for the Talema (pdf)  here (http://www.nuvotem.com/en/products/pdf/0030P1_0209.pdf) but the color codes for the wires in the specs does not match the colors of the wires on my toroid :?

Does anyone know this model and help me identify the wires??
Title: SSL HELP THREAD!!!
Post by: rstreber on January 28, 2005, 08:22:03 PM
I'm still trying to figure out my R channel distortion problem;  I'm tracing signal around, but, being a very new newbie, I'm not confident that I know what's abnormal or what to look for.  
I'm getting very distorted signal at pin 1 and 8 of the R ch. 2180, and no signal at the L channel 2180 - should there be audio here?  I'm also getting distorted audio just after the R unity gain 27k resistor and no audio here on the L ch.  And I'm getting clean signal at pin 8 of the SC 2180 but distortion at pin 7.  If anyone can give me some pointers as to what I should idealy be finding / hearing, I'd greatly appreciate it!! I'm learning a lot as I go through this ciruit, but I still know woefully little about what's actually going on in this thing!!  
Thanks
Title: SSL HELP THREAD!!!
Post by: Zee1usa on January 31, 2005, 03:42:02 AM
Hello,

 I finished my GSSL and it is compressing on both channels, but one is
louder than the other.

 I injected a 1kz sinewave into XLR's and here is what i noticed.

 Left Input: NE5534 pins 2(IN-),3(IN+),5(comp),6(OUT) are the SAME size  waveform. No change at all?!?#$?

  Right Input: NE5534 pins 2(IN-),3(IN+) waveform are same but 5(comp),6(OUT) are DOUBLE in size waveform compared to pins 2,3.

I believe the "Right Input" is correct it is the "Left Input" pins 5(comp),6(OUT) which have not DOUBLED in size as I am thinking they should be.

I checked all my voltages they all look good. I have checked resistors, checked for solderbridges etc. I swapped NE5534's without change. I swapped the VCA's without any change.

All components stuffed are correct around the NE5534 circuits.
I checked all these.


Any insight would be appreciated!

 Thanks,

 Z

 :wink:  :guinness:
Title: SSL HELP THREAD!!!
Post by: t-wurst on January 31, 2005, 03:54:08 AM
Need some help please guiding me in the right direction.

Problem:
I wired and fired up 2 of those nice SSL.
One board came out a bit dirty due to a crappy solder tip and i forgot to wipe off the photostuff with aceton.
The other board looks pretty good. Everything is shiny, got a brandnew tip, measured every resistor before it´s soldered (except of the MegaOhms cause my DMM is too small (!) - uh, maybe there´s the fault?! )
I have all the right voltages +/- 15 +/- 12, the XLR´s are grounded, the unit passes audio. dbx in right direction (used verbos´). I have bridged the Makeup/Bypass conn. on the control board with a jumper because i still miss the switches. (both bypass points and the com/on points) Meter works like it should, threshold drives the meter different, meter follows signal.
BUT
Makeup doesn´t work, there is no audible compression and in my opinion, the voltage regulators getting too hot. It takes maybe one or two minutes, then u can´t touch them much longer than a few seconds. Maybe this is normal, i used 2x18V torroid? So i switch it off and don´t have much time for measurements.. :?
Voltages vary on 074 pin 7, somewhere between +0,15 and -1,9 Volts, i measured 072 pin 8 i think, but there are not the voltages inverted like Jakob suggested.

The same behavior with the other control board.
I don´t had much time last week, maybe today i can spend a few hours...

Any hints? Thanks in advance  :wink:

toby
Title: SSL HELP THREAD!!!
Post by: Zee1usa on February 01, 2005, 12:28:56 AM
Bump...


 I am having OP AMP issues with my XLR in  NE5534 output pin 6.

I really just need to know what the output signal pin6 should look like
compared to the input signals pin 2/3?

Is it amplified or is it soposed to be at unity?

I am getting 2 different results on output and I just wondered which is correct? Please see my post above.

Thank you for any insight you may offer,

 Z :?
Title: SSL HELP THREAD!!!
Post by: Greg on February 01, 2005, 01:39:22 AM
Gyraf:

I've come across a slight problem with my latest GSSL that I'm building for a mastering engineer here in New Orleans. The GSSL itself works great... my question is regarding a metering issue. I decided to go with the Modutec meter from Mouser. I'm trying to scale it so 6dB gain reduction is fully deflected.  In fact, I was actually going to wire in a switch for 2 scales... one from 0-3dB and one from 0-6dB. But for some reason (even with the 2K resistor replaced by a short) I'm only getting 40% deflection. I'm assuming it's a meter issue since I had a spare Weston that I could fully deflect with no problem at 6dB GR. I was just wondering if you had any ideas to get more current to the meter. Maybe a current amplifier I guess, but that'd be a pain in the [email protected]#?

I know I can use a different meter, it's just that I already have the front panel all drilled out for this meter.

Thanks.
Title: SSL HELP THREAD!!!
Post by: Mundox on February 01, 2005, 01:55:55 AM
Hey Greg, I am using the same meter, and I get 30db reduction full scale with a 1k resistor! I think it's the meter. So when the meter barely moves  you get 2-3db reduction. Those meters are a bit slow .
Title: SSL HELP THREAD!!!
Post by: gyraf on February 01, 2005, 05:18:46 AM
Greg,

Put in a trimmer for the 2K resistor, and adjust untill you think your meter makes sense.

Z,

There's either a wrongly-wired XLR, some short, or a wrong resistor somewhere around the input opamps. Check and recheck.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on February 01, 2005, 11:10:23 AM
Gyraf: That's what I did... but even with that 2K replaced with a dead short, it still only deflected 40% (at 6dB GR). My goal was to make 6dB 100% deflected.  So I think, as Mundox suggested, this is not a very good meter.
Title: SSL HELP THREAD!!!
Post by: gyraf on February 01, 2005, 11:59:39 AM
Nope, you'd need a different meter to do this then. Or possibly a second meter buffer, that will output enough current for your meter. Maybe two paralleled halves of a 5532?

What is it? 10mA full-scale? Isn't there an internal shunt resistor you can remove?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on February 01, 2005, 01:21:51 PM
Quote from: "gyraf"
Nope, you'd need a different meter to do this then. Or possibly a second meter buffer, that will output enough current for your meter. Maybe two paralleled halves of a 5532?

I'll talk to the guy I'm building it for and see what he wants me to do.

Quote from: "gyraf"
What is it? 10mA full-scale? Isn't there an internal shunt resistor you can remove?

The specs said it was 1mA full-scale, but it's obviously not. I'll check for an internal shunt resistor.
Title: SSL HELP THREAD!!!
Post by: Zee1usa on February 02, 2005, 01:00:44 AM
Quote from: "gyraf"

Z,

There's either a wrongly-wired XLR, some short, or a wrong resistor somewhere around the input opamps. Check and recheck.

Jakob E.



It appears that the Gustav board layout for input XLR'S is:

 - + 0 + -

The gyraf board layout indicates:

+ - 0 - +


Am I the only one that has run into this issue or if I am wrong please correct me.

Thank you,

Z
Title: SSL HELP THREAD!!!
Post by: gyraf on February 02, 2005, 03:25:00 AM
Gustav's boards are the latest revision. Known good.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Zee1usa on February 02, 2005, 03:46:09 AM
Thank you for the response.

I reversed the XLR's opposite of the Gyraf diagram and now

my signals on pin 6 of both NE5534 look exactly the same.


I traced the wiring on Gustav's pcb and it appears to be opposite of the gyraf
diagram as mentioned above.

I want to believe Gustav's pcb is the same as the gyraf diagram, but it appears not. Do I have an older revesion of his pcb that may have been reversed? or...do i need to take two asprin and go to bed?

 :?
Title: SSL HELP THREAD!!!
Post by: dukasound on February 02, 2005, 07:24:30 AM
Hi
I found this small dual VU. Does anybody know some details and specification and can I use this in SSL. This is DC VU. I measured 603ohm across + and -.  There is nothing inside meter (no resistor, diodes)
(http://www.dukasound.cg.yu/Data/SMALL_VUa.JPG)
Title: SSL HELP THREAD!!!
Post by: cwatkins on February 02, 2005, 02:36:24 PM
Problem:

I had the SSL working, (it ran for hours, I love it!, classic buss compresser) it had this problem at first, so I'm assuming
there is a short, but I'll be darned if I can find it.

Details:

If the control board is disconnected, everything seems to work great,
+6 db great quiet auido passes flawnessly, nothing how runs great.

Plug in control board and not the makeup gain pot, but the threshold pot,
if turned to right, makes the led go dim, now I saw gyraf make a reference to the makup gain pot causing the led to go off, but I can't find
that thread or a similar one that specs the threshold pot doing that.  I've done some voltage traces back and foreth between the tl074 and the control board pins, check continuity on the cable and looked for the short, if the threshold pot is turned all the way down, in bypass mode, it almost works and passes audio, but anything to the right almost immediately causes the a large hum and no audio. and the voltage to drop to about 4v where it was 6.5.

anything sound familar?

on most of the pins and -10 where it was -12 before on the pot.
Title: SSL HELP THREAD!!!
Post by: cwatkins on February 02, 2005, 07:50:05 PM
actually, let me re-phrase that, I've read the entire thread, again, and,
My problem is alot like bladesg's, except that there was no "answer" to
his problem. just kind of a description initially of the same problem,
if it's a cold joint, maybe somebody can point me in the right place, I've
been around the board a bit..
Title: SSL HELP THREAD!!!
Post by: cwatkins on February 03, 2005, 01:12:29 AM
Just becase I looked everywhere and it wasn't what I thought,
it was because I had wired the transformer wrong.. it wasn't in series..
Why it worked earlier I'm not sure..But it definately needs the juice.

So, was those dange transformers again, same thing tripped me up
in the pultec.  You'd think I'd learn..
Title: rotary power switch
Post by: MLM on February 16, 2005, 12:09:32 PM
hi, just a quick question about the ssl power switch, is it ok to use a standard lorlin rotary to switch the 240v, or is it better to put it after the transformer secondary, switching the 15/-15v? (leaving the earth unswitched)
hope that makes sense??! thanks in advance!
Title: SSL HELP THREAD!!!
Post by: gyraf on February 16, 2005, 12:54:03 PM
Quote
is it ok to use a standard lorlin rotary to switch the 240v


For mains switching, you NEED to use a switch rated for this. You can't use a lorlin like the others - you will need a "real" mains switch.

Switching after the transformer is no good idea, as the unit in effect isn't powered down when off..

Jakob E.
Title: rotary mains sw
Post by: MLM on February 17, 2005, 07:25:57 AM
thanks for the extra quick reply jakob! can't express how grateful i am for everything you've done/are doing with your incredible projects, and the forum... hope that one day i'll be able to somehow pay you back, anything you ever need from the uk let me know...

back to the rotary switch - do you by any chance have a source for 240v rotary's? maplin have discontinued theirs and i can't seem to find anything in farnell/RS etc.. (unless i'm being particulary blind).. thanks again!
Title: SSL HELP THREAD!!!
Post by: gyraf on February 17, 2005, 08:10:28 AM
Hi MLM,

In the commercial Gyraf equipment I use the Lorlin rotary power switches - sourced from RS:

RS Part no. 316-800

(http://img-europe.electrocomponents.com/images/C316800-02.jpg)

..at a bit less 1£/pc at 5pcs. They work very well.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: MLM on February 17, 2005, 10:52:20 AM
just placed an order  - thanks again jakob!!!
Title: SSL HELP THREAD!!!
Post by: thedug on February 22, 2005, 02:42:23 AM
I just realized that when I set my ssl to 1ms attack (pos. 3) it stops compressing. The makeup gain seems to still work, but the meter falls all the way to the left, no gain reduction.

Any ideas what to look for?

d./
Title: SSL HELP THREAD!!!
Post by: gyraf on February 22, 2005, 02:56:32 AM
A break or a short around that pin of the switch?
Title: SSL HELP THREAD!!!
Post by: dukasound on February 22, 2005, 05:51:58 PM
Hi
I am finishing my GSSL (missing some small parts and chassis) :grin: .
I have a couple of questions:
-What cap is between two 1K?
(http://www.dukasound.cg.yu/Data/Cap.jpg)
-If I use 100uA, 200uA or 250uA what resistor I can use instead 2K?
-Find only Jamicon caps :sad: . Is it enought good for passing audio?
-I will use THAT 2181LA and  suppose I dont need 47K for distortion trim?
Thanks to Lampas who send me boards and THAT 2181 :thumb:
Duka
Title: SSL HELP THREAD!!!
Post by: Greg on February 23, 2005, 09:51:00 AM
Quote from: "dukasound"
What cap is between two 1K?
(http://www.dukasound.cg.yu/Data/Cap.jpg)
100n I believe... check the schematic to be sure.

Quote from: "dukasound"
If I use 100uA, 200uA or 250uA what resistor I can use instead 2K?
For 100uA, you need to shunt the meter with a 330R... start with the 2K in the board then adjust the 2K if you want to show a different range on your meter.

Quote from: "dukasound"
Find only Jamicon caps :sad: . Is it enough good for passing audio?
I used generic caps on one of my SSLs and it sounds much "darker" than the other one I built with Panasonic FCs. They both have their advantages and disadvantages I guess.

Quote from: "dukasound"
I will use THAT 2181LA and  suppose I dont need 47K for distortion trim?
I removed all components connected to pin 4, as stated in the THAT sheets. Some people have had success with just removing the trim pot, but I went ahead and removed 10K and 68R as well.

And to answer your PM here, I did not use heatsinks.

 :thumb:
Title: SSL HELP THREAD!!!
Post by: dukasound on February 23, 2005, 02:38:59 PM
Quote
100n I believe... check the schematic to be sure.

Thanks Greg :thumb:
On schematic are 100p parallel to 1K :?
What other guys use :?:
Title: SSL HELP THREAD!!!
Post by: dukasound on February 25, 2005, 01:25:24 AM
Hi
Please guys, what cap you used here?
(http://www.dukasound.cg.yu/Data/Cap.jpg)
On shematic is 100p but I saw 0,1u on some GSSSL
Duka
Title: SSL HELP THREAD!!!
Post by: RemcoV on February 25, 2005, 06:36:48 AM
Hi Duka,

I used 100pF on that spot. I put 100n there in the beginning aswell, but then your vca's will start to act funny.


Greetz
Remco
Title: SSL HELP THREAD!!!
Post by: radiance on February 25, 2005, 07:08:21 AM
Quote from: "RemcoV"
Hi Duka,

I used 100pF on that spot. I put 100n there in the beginning aswell, but then your vca's will start to act funny.


Greetz
Remco


What do you mean by acting funny?
I have had a 100n in there for some time and did not notice anything funny. I will change it to a 100pF though.

Regards,

Radiance
Title: SSL HELP THREAD!!!
Post by: dukasound on February 25, 2005, 10:22:44 AM
Quote from: "radiance"
Quote from: "RemcoV"
Hi Duka,

I used 100pF on that spot. I put 100n there in the beginning aswell, but then your vca's will start to act funny.


Greetz
Remco


What do you mean by acting funny?
I have had a 100n in there for some time and did not notice anything funny. I will change it to a 100pF though.

Regards,

Radiance

Any other comments (who made GSSL) :?:
Title: SSL HELP THREAD!!!
Post by: Greg on February 25, 2005, 11:28:54 AM
I have 100n is both of mine... I haven't noticed anything odd. What's the marking on the PCB say? I don't remember.
Title: SSL HELP THREAD!!!
Post by: radiance on February 25, 2005, 11:34:52 AM
Well, al those 100n cap's were marked as ".1".
The cap in question did not has this ".1" marking, in fact it has no marking at all, maybe due to not enough  space on the pcb...
Then there is a 100pf marking which is probably ment for two caps.
Title: SSL HELP THREAD!!!
Post by: radiance on February 25, 2005, 11:55:26 AM
Maybe only certain VCA's are affected by this wrong cap valeu...?
I used a THAT 2180 LB.

@Greg & Remco: which VCA did you use?
Title: SSL HELP THREAD!!!
Post by: Greg on February 25, 2005, 12:53:36 PM
One is built with DBX 2151s and the other has THAT 2180LBs...
Title: SSL HELP THREAD!!!
Post by: BladeSG on February 25, 2005, 07:55:47 PM
The pictures from Kev's Group DIY page have what looks like a 100nF MKT cap there. I used 100nF caps in both of my GSSL's (still need to be racked) with 2180LA and 2180LB VCA's and there's no apparent problem I know of either.

http://recording.org/users/kev/G_SSLclone.htm
Title: SSL HELP THREAD!!!
Post by: daArry on February 26, 2005, 04:25:55 AM
I wish these cap issues got sorted out once n for all lol...

Seems to come up every few months where then a few more discrepancies between the schem and whats marked on the PCB legends come to light...

If you look at the cap in question on the other VCA ckt you can see it's marked as .1 and the one by the side of the 5534 is 100p...
Title: SSL HELP THREAD!!!
Post by: RemcoV on February 26, 2005, 05:43:23 AM
if i look at the schamatic i see (in the 202-emulation part)  2 100pf caps and 1 100n cap. So when there were some weird things going on in my comp so i looked at that, and also did some other things (removing the trimpot and 1M resistor.  So i could very well be that not the caps but the trimmers were causing my troubles.. (if so, i'm sorry for the confusion)
I uses 2180LC vca's in my version.

Greetz
Remco
Title: SSL HELP THREAD!!!
Post by: Rogy on February 26, 2005, 06:02:14 AM
Gentlemen, the cap question is already discussed and clearly answered before in this thread:

http://www.groupdiy.com/index.php?topic=2566

Jacob stated:

"The feedback cap in the emulation circuit is an experiment. It started out as a 100p stabilisation cap (at rather high frequency, admitted), but the 100nF with it's slight integration turned out to make the circuit work in a (subjectively) nicer way. Yes, you could argue that this wouldn't affect the "real" 202 if you use that one, but these will behave a bit different anyway."

So he suggests 100nF although 100p will also work.


As for the usage of That 2181 VCA's (which are NOT pre-trimmed), this document should be read:
http://www.thatcorp.com/desnotes.html#DN133

Changes I made to the SSL schematic for usage of 2181A are:

On the main VCA emulation circuit, omit the 68R resistor from pin 4 to GND.

On the main VCA emulation circuit, replace the 10K resistor from pin 4 to the "Distortion Trim" pin by a piece of wire (= short).

On the main VCA original circuit, replace the 1M resistor from the THD leg of the 202 to the 50K trim pot with a 680K resistor. The trim pot value remains the same (50K).

This is how I built mine; to be tested within a few days when I find the time.

Above values are for That 2181A; different values for 2181 B and C can be found in the That document I linked to above.

Just removing the 68R, 10K, 1M and 50K trim resistors totally defeats the distortion trim, which is not good for 2181 VCA's. This only works for PRE-TRIMMED 2180 VCA's.


Hope this helps!


Regards,

Rogy
Title: SSL HELP THREAD!!!
Post by: radiance on February 26, 2005, 07:10:23 AM
Thanks Rogy!
Title: THAT 2181LA
Post by: dukasound on February 27, 2005, 06:00:20 AM
Hi
I exchange resistors after Rogy's sugestions and after reading That's explanations  about substitute 2150 to 2181 (Rogy, thank you) :thumb:
Is schematic now right for use THAT 2181LA?
(http://www.dukasound.cg.yu/Data/GSSL_2181A.jpg)
Just to know :roll:  
Need exchanging parts  if we use 2181 instead 2150 in sidechain?
Why VCA in sidechain is feeding with 12V?
THAT suggest 5K1 on pin5 (V-) and we use 3K9?
We stoped disscusing about 1K, 1M, 1N4148 and point "A" connections who is difference than original circuit?
Duka
Title: SSL HELP THREAD!!!
Post by: kryckmeister on February 28, 2005, 06:52:03 AM
Any ideas??? I've been messing around with my SSL for a couple of days now, and it seems to be working, but no audio signal runs through it. I used a voltmeter (anyone?) and everything seems to be fine when checking the XLR connectors. I'm really out of ideas now.
Please help.
Title: SSL HELP THREAD!!!
Post by: radiance on February 28, 2005, 12:18:30 PM
@ Viitalahde: I know this sounds obvious but do a thorough search for shorts / solder bridges in the side chain area. Also meassure if al the IC's voltages are correct.
I had a short once that made me crazy for a couple off day's. Only after meassuring all pins off the TL 074 and the TL 072 I found out where it was.
The  pcb layout is very tight at some places...
Title: SSL HELP THREAD!!!
Post by: cipo on March 02, 2005, 06:10:13 AM
Hi, i'm new in this forum. Maybe I mistaked to open a new topic (testing ssl). i think this is the right place.
Just finished my ssl clone with 2180 vca's. It seems to work well but i still have problems on low frequencies compression. If I send a 60 or 80 or 100 Hz sine signal to input and let it compress even just 4 db the result is distorted at fast attack and release. This happen until 400 Hz about. Could somebody help me?
Thank you and best compliments to everybody for the great cooperation.
Title: SSL HELP THREAD!!!
Post by: gyraf on March 02, 2005, 07:17:19 AM
Cipo,

I believe this will happen with just about any compressor you try this with, at similar settings.

Low-frequency content and fast timing dosen't work out neither in theory nor in practice.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: cipo on March 02, 2005, 07:38:59 AM
ok, thank you Jackob.
One more question:about the threshold. Is it normal that in this project if I turn all the threshold up it respond with infinite compression and I can't hear any signal in output? ...or there is something i mistake?
thanks
Title: SSL HELP THREAD!!!
Post by: gyraf on March 02, 2005, 07:54:56 AM
Quote from: "cipo"
about the threshold. Is it normal that in this project if I turn all the threshold up it respond with infinite compression and I can't hear any signal in output? ...or there is something i mistake?


Shouldn't do so. Check for shorts and component values around there, as always.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: radiance on March 04, 2005, 08:46:12 AM
Yes, solder bridges are a P.I.T.A.
Title: SSL HELP THREAD!!!
Post by: Rogy on March 05, 2005, 02:18:54 PM
Answers to Duka's questions:

Quote
Is schematic now right for use THAT 2181LA?


Yes, it's correct.

Quote
Need exchanging parts if we use 2181 instead 2150 in sidechain?


Good question. It works witk the actual component values but maybe some things could be improved. I'll have to take a closer look at that later.

Quote
Why VCA in sidechain is feeding with 12V?


Because the VCA needs a very stable supply voltage. If the supply voltage fluctuates, the control voltage will also fluctuate and the gain reduction as well (VCA = current in/out device).

Even if the +/-15V fluctuates, the +/-12V will likely remain stable and the gain reduction as well.

Quote
THAT suggest 5K1 on pin5 (V-) and we use 3K9?


This resistor determines the current available to the device. Smaller resistor than recommended is not a problem because the VCA only uses the current it needs. If more is available, that's fine but doesn't change a thing. So 5K1 is fine, 3K9 also.

Quote
We stoped disscusing about 1K, 1M, 1N4148 and point "A" connections who is difference than original circuit?


The point A connection is same as the original on the PCB but is indicated wrong in the schematic.

Greetz,

Rogy
Title: SSL HELP THREAD!!!
Post by: gyraf on March 06, 2005, 07:13:55 AM
Thanks, Rogy!

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on March 08, 2005, 11:19:37 AM
On my next two SSLs, I plan to use a toggle switch for my bypass and power instead of the rotary. For the bypass, a DPDT switch is needed, right? And I just want to make sure that the switching needs to be ON-NONE-ON, correct? I think this means there will only be two selectable positions... I've seen the ON-OFF-ON, which I think will have three, and I don't think I want that.

And for power I just need one pole.

I just wanted to make sure because the toggles I'm looking at are kind of expensive.
Title: SSL HELP THREAD!!!
Post by: gyraf on March 08, 2005, 12:08:59 PM
Yes, a double-pole on-on switch. One will have to disconnect sidechain, the other to disconnect makeup gain
Title: SSL knobs
Post by: dukasound on March 17, 2005, 10:20:18 AM
Anyone knows part number of SSL knobs from Sifam?
(http://www.dukasound.cg.yu/Data/XLGComp_knob.JPG)
Thanks
Duka
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 18, 2005, 02:20:47 AM
Well, I just wrapped up my second SSL, plugged it in and flipped it on....wa-la! Nice bright blue lights!.....

......and no sound.  :cry:

I have no idea what's wrong and don't know where to begin looking. It passes absolutely no signal, but gets power all the way through to the control board (otherwise there'd be no power light, right?). Here's what I know:

When I opened it up and compared it to my other one that works stellar, I noticed the (+) and (-) leads from the trafo to the IEC were backwards. So I swapped 'em and tried again....same result. Also, there's a pop when I connect or disconnect a cable from the left input, but not from the right or either output.

Help! Where do I start?
Title: SSL HELP THREAD!!!
Post by: radiance on March 18, 2005, 05:32:40 AM
@Duka:  knobs are   S151.006   grey    
             caps are  C151   blue  

You will not get the same blue as a standard color. It's more greenish blue but it looks ok. I used them on  my clone  (http://www.rolandklinkenberg.com/ssl/sslfront.jpg) as well.
Title: SSL HELP THREAD!!!
Post by: dukasound on March 18, 2005, 06:51:37 AM
Quote from: "radiance"
@Duka:  knobs are   S151.006   grey    
             caps are  C151   blue  

You will not get the same blue as a standard color. It's more greenish blue but it looks ok. I used them on  my clone  (http://www.rolandklinkenberg.com/ssl/sslfront.jpg) as well.

Thanks.
This is nice clone :thumb:
Duka
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 18, 2005, 05:38:06 PM
Ok, so I started testing chips and they're all ok. Then I started testing voltages and found that the Vin on my 7915 was varying between -22V and -24V, and the thing is scorching hot, while the 7815 is good at +14.87V and barely warm. I'm pretty sure that's not good, so I'm replacing the 7915, but will that likely solve my problem, or is the problem somewhere before the 7915 and putting another one in will just get it fried, too?

Any ideas are greatly appreciated.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 18, 2005, 06:42:55 PM
Ok. 7915 replaced, same result. Comparing values with my other SSL that works, I see it's supposed to be around -22V on the Vin, but the Vout should be my -15V, and it's not. It's measuring -33mV. Milivolts! And this is a brand new regulator. Where is my problem? Bad cap before it? Diode? Beuller? Beuller?......
Title: SSL HELP THREAD!!!
Post by: dufo on March 18, 2005, 08:33:18 PM
Quote from: "RemcoV"
Andre:

I found the SSL to be very sensitive as standard, and kicking in quickly aswell.
I solved this with adding an extra resistor with the bottom threshold line (the one that goes to the potmeter from the board) i used i think 56k and that limits the threshold range a bit, but it makes it way more usefull (to my opinion atleast)

hope it helps!
Remco


AHHH!!! VERY interesting Remcov. Is this to counteract the meter banging over at full scale as soon as you start the threshold CCW?? I may have to try this today. Can you be any more specific exactly where you put the resistor and if indeed it was 56 K? Thanks alot .  :grin:
Title: SSL HELP THREAD!!!
Post by: PRR on March 19, 2005, 12:42:59 AM
> I'm replacing the 7915, but...

You do remember that a 79xx has a different pinout from a 78xx? And that the tab is the center leg, and on 79xx usually can't touch Ground?

> It's measuring -33mV. Millivolts!

There is a short on the output.

Study the circuit board (I'm not going to go looking for the plan) and figure out how you can disconnect the output of the 7915 from everything it feeds. Put a 1K resistor from Out to Gnd and check the voltage: should be 15V and not-hot.

If it works with the 1K dummy load, but not when connected to all the -15V loads on the PCB, you have to find your solder-bridge, reversed chip or electrolytic-cap, or other mistake.

> there's a pop when I connect or disconnect a cable from the left input, but not from the right or either output.

If it was just bad -15V, it would be the same on both channels. It isn't, so that's a clue. Unfortunately it may be "normal" to pop when -15V is -0.033V (with full +15V) so we can't be sure if this points to the left or right channel.

> the (+) and (-) leads from the trafo to the IEC were backwards.

Does not matter one bit.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 19, 2005, 01:01:55 AM
PRR,

Thanks for the help. I didn't remember the pinout difference at first, but then saw it laid out on the packaging and remembered. That's when I measured the -33mV.

In the meantime, I've since removed the rectifier and swapped it into the working comp. It was fine, but the other rectifier I took out got broke in the process, so I have to go get another one tomorrow before I can try the 1K resistor test.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 19, 2005, 03:50:26 PM
Put in the new rectifier, disconnected the 7915 output from everything, put a 1K resistor on it and I read -26mV. So, does that mean the new 7915 is bad, or maybe one of the 1000uF caps before it? There isn't much else I can think of. All the 12V stuff works and reads just fine, but I don't think that would affect the 15V anyway....maybe I'm wrong.
Title: SSL HELP THREAD!!!
Post by: alk509 on March 19, 2005, 04:05:55 PM
Quote from: "bubba_b"
I've since removed the rectifier


Since your +15V and your +/-12V supplies are working, and they're all fed from the same rectifier bridge, I doubt that has anything to do with the problem... I also doubt your regulators are bad. Check your solder joints, and after you make sure they're fine, check them again. Go through this process a few times.

Make sure you got the pinout right by downloading the datasheet to the regulator you're using from the manufacturer's website. You're not shorting the tab to ground or anthing, are you? With the regulator out, check for continuity/low resistance between ground and where the output pin of the regulator goes.

Peace,
Al.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 21, 2005, 03:08:39 AM
So I've pulled out the regulator twice, resoldered it, went over all the solder joints with a fine tooth comb and can not find a solder bridge or stray wire strand or anything of the sort. Looking at the schematic, it looks like the only things between the trafo and this regulator is: (1) 1000uF cap, the bridge rectifier and (1) 100nF cap. I haven't replaced the caps yet, but if either of those don't fix it, then it has to be something after the regulator, but I don't understand how that could be. But then again, I am a novice at this.
Title: SSL HELP THREAD!!!
Post by: RemcoV on March 21, 2005, 06:25:03 AM
@ Dufo

If you look at the control board you have the 2 potmeters on either side of the board connected with wires.
If you take the threshold pot, and put the resistor in place of the bottom wire going from the pot to the controlboard.

That should numb you threshold sensitivity.

Hope it helps.

Remco
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 21, 2005, 01:52:12 PM
Now it's really weird, but it may be a sign of what's exactly wrong. I've replaced both caps (1000uF and 100nF) in line with the 7915 and now when I measure the Vout pin on the 7915, it fluctuates between +.5mV and -150.00mV consistently. Any thoughts?
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 21, 2005, 02:36:40 PM
Ok, I took out the 7915 and put in another one and now it's back to reading -33mV steady. I'm almost ready to just take it somewhere and have them deal with it.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 22, 2005, 07:11:34 PM
bump...
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 23, 2005, 03:17:02 AM
After many hours fiddling with this thing, I finally tracked down where the problem was coming from and found a solder bridge on the input side. Grounded itself out. So, I fix it, recheck my voltages and they're normal (about -15.2V on the 7915 Vout). So I'm stoked.....until I plug it in to see if it actually works. No. Won't pass signal and the control board does nothing.

Back to square one.
Title: SSL HELP THREAD!!!
Post by: RemcoV on March 23, 2005, 03:45:55 AM
bubba, did you already check the 12V/-12V rail aswell?
and best is to check first if all your opamps get their power as they should.
So for the 5532 there should be 30Volts between pins 4 and 8.
for the 5543 there should be 30 volts between pins 4 and 7.
the TL074 should have 24Volts between pins 4 and 11, and the TL072 should have 24Volts between pins 4 and 8.

If they are healthy you can check the audio going thru. Do you have access to a scoop? that would make the search allot easier.

hope it helps

Remco
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 23, 2005, 12:58:49 PM
Checked voltages across all my chips and they're all ok, gettin' the right juice. Does that mean they're good, or could there still be something wrong with one of them? If they're good, then where should I look next?

No, I don't have a scope, but I have a friend who works at the Conservatory of Recording Arts and Sciences here in town who can take a look at it tonight and he's got one. I'll let you know what happens.

BTW, I appreciate the help, RemcoV.  :grin:

On another note, the Conservatory has a 4056G series SSL. Is my compressor comparable to the one in that board? I'd like to A/B them, but if they're that much different, it really wouldn't matter.
Title: SSL HELP THREAD!!!
Post by: RemcoV on March 23, 2005, 07:10:39 PM
right, so we need to check to see where the audio disapears.
When you've got access to a scoop check the folowing things(ofcourse you apply some audio to the inputs):
- check pin 6 of the 5534s, those are the de-balancers
- check pin 1 and 7 of the 5532s. those are the output balancing circuits.
Probably it wil have disappears at the outputs ( i recon)

then check the folowing things:
In the sidechain, there should be signal at TL074 pin7, variable with the threshold pot.
At 074 pin 14 there should be a rectified DC voltage following input signal level. At 074 pin8 there should be a replica of this signal, but now timed with attack and release time.

At TL072 pin2 you find this signal again, but added with a variable DC voltage from the "makeup gain" pot. So this voltage follows both input signal level AND position of the "makeup gain" pot. This signal in turn controls both the main VCA's.

At TL072 pin7 you find the signal from 074 pin8 again, but this time mixed in with a variable DC voltage from the "threshold" pot. So this voltage follows both input signal level AND position of the "threshold" pot. This signal in turn controls the sidechain VCA.

With this you can check if there is signal inthe sidechain.

Hope it helps!

Remco
Title: Measuring voltages
Post by: Flundran on March 24, 2005, 10:41:48 AM
I've just been measuring on my SSL trying to find out why it distorts the sound.

It seems the -15V rail and the -12V is ok, but the others (+12v and +15v) is far to low.
I measured on the WO4 bridge and found out I've got -17.8V on one side and only 5.4V on the other. Is the WO4 broken? Is there I way to measure this component with a multimeter?

/Rikard
Title: SSL HELP THREAD!!!
Post by: radiance on March 24, 2005, 12:06:41 PM
Wo4 bridge is basicly 4 diodes so a diode tester will do...
Title: SSL HELP THREAD!!!
Post by: martthie_08 on March 24, 2005, 01:33:27 PM
Hello, I am just finishing my GSSL and have two questions, though first of all: big thanks to Jacob for making all those ressources on the ssl comp available to the public, this is only my second diy project and I am really happy with how it's turning out to be...

1. I would like to use a 6 volt power indication lamp like on those old Fender guitar amps instead of the red diode on the control pcb, what is the best way of powering this? I also need to apply 12 volts to the lamp on the vu illumination - any hints? I have a really beefy PT (80 Watts - don't ask :) so would it be best to hook up to the PT output and set up an extra little board that will give me the correct voltages? has this been answered before?

2. Is it possible to get the gain reduction on the vu set up reversed way, as on an 1176, for example? I got a Sifam AL29 I'd like to use for my Compressor...

I just "completed" the project this afternoon and have done a short listening test, which was very pleasing:) I will comment on sonics in detail  later, as there are still some things to do, I want to change the threshold range, as all the action is happening on only about one-fifth of the pot range. Then I must adjust the ratios, and the frontpanel is still in work, and... there is a lot of work to do!
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 26, 2005, 04:12:20 PM
It seems like every time I fix one thing that's wrong, another one pops up. Here's my newest problem:

I have audio and compression just fine in the right side (yeah!). The left side, however, is considerably lower (-15db) and distorted, but intermittenly seems to work and then instantly clip back down to -15 again (all within about a half of a sec.). It sounds like a short somewhere, but I'm not exactly sure where to look. I checked for shorting on the 5532's between pins 1-2. Right side reads 2.2mV, left side reads 0.2mV. Swapping the chips makes no difference. I've ruled out the 10k resistor and 100p cap coming off pin 1 (the 100p goes back to pin 2).  Any ideas where to look next I'd greatly appreciate.

I know I'm close and it's keeping my spirits up. I just pray that once this is fixed, it'll be all done and ready for rock!  :grin:

p.s. I have a small audio file I can email to anyone if hearing what it's doing would help.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 28, 2005, 12:57:49 PM
bump, please
Title: SSL HELP THREAD!!!
Post by: gyraf on March 28, 2005, 01:12:15 PM
..Check, check and double-check everything. And try swapping ic's between channels, if one channel is fine...
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 29, 2005, 12:39:58 PM
Thanks, gyraf. I checked, checked and re-checked every solder joint on the board and they are all fine. I even resoldered a few that were even slightly close to each other just to make sure. Also, swapping IC's had no effect. The same (left) channel still has the same problem.

It seems to be doing this: 1) on initial start-up after sitting off for awhile, it works in both channels for about 5 seconds, then the left goes down -15db and is fuzzy. It stays that way thereafter. 2) I didn't really notice it at first, but my friend pointed out it sounds "phasey", and it does. Kinda like it was recorded in a small wooden box? 3) controls all work, but meter doesn't move.
Title: SSL HELP THREAD!!!
Post by: radiance on March 29, 2005, 12:55:23 PM
Did you also swap the VCA's?
Obviously you did cause they're IC's as well but just in case....
Title: SSL HELP THREAD!!!
Post by: underthebigtree on March 29, 2005, 01:53:09 PM
Hi folks -

I have an input problem. Perhaps someone else has some insight, 'cause I'm out of ideas. Here goes:

Left input is several DB quieter than right. Everything is fine coming into the 5534 input opamp. Pin 6 coming out is significantly quieter than the same on the right opamp. I've swapped the IC's, no change. I've swapped the dbx chips downstream, no change. I've checked the values of the 22K resistors around the input circuit, and they all seem OK.

A gain problem like this has to be the feedback resistor, right? I'll re-solder for cold solder joints, but if anyone has any other ideas, I'd love to hear 'em.

Thanks,

Nick
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 29, 2005, 02:02:37 PM
radiance,

Yes, replaced both VCA's and no change.
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 31, 2005, 02:23:06 AM
Found a bad 100u cap in the left output channel, but replacing it didn't fix the thing. If anyone could please take a listen to what it's doing and maybe give some insight as to what in the world this thing is doing, I would be eternally grateful. Here (http://us.f2.yahoofs.com/bc/409bf04e_50c/bc/SSL/comp+prob+1.mp3?bfYc6SCBzSX3AMzj) is the file. It starts out compressing, then you can hear what it does when I turn up the makeup gain, then switch to bypass, and then back into compressing mode.

I can't stress enough how many times I've gone over this board looking for solder bridges and came up empty. Something is just plain bad, I just don't know what.
Title: SSL HELP THREAD!!!
Post by: radiance on March 31, 2005, 05:54:44 AM
That's a bad link...
Title: Voltage drop
Post by: Flundran on March 31, 2005, 08:28:34 AM
I have a stange voltage drop right after the W04 bridge. The '-' side is right (-17.8V.. I have a 2x18 trafo) but on the plus-side of the bridge I only get +5.20V. I measured the W04 and it seemed to be ok. What can be the problem?
/Flundran
Title: SSL HELP THREAD!!!
Post by: gyraf on March 31, 2005, 09:01:33 AM
Flun,

Something is shorting the output of the 7815 regulator.

Check, check, and double check..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on March 31, 2005, 10:13:38 AM
I unsoldered the wire to the input of the 202xt, and suddenly the voltage is right. Does this mean something is wrong with the VCA? How do I check it?
/Flundran
Title: SSL HELP THREAD!!!
Post by: bubba_b on March 31, 2005, 01:27:28 PM
radiance,

Sorry about that. Here (https://www.web-a-file.com/guest.cgi?section=3&sessionid=guest01603893119593561110221995868222594559296441414307) is the file, again. If this doesn't work, let me know. Thanks for trying.
Title: SSL HELP THREAD!!!
Post by: bubba_b on April 01, 2005, 03:53:30 AM
bump
Title: SSL HELP THREAD!!!
Post by: Flundran on April 01, 2005, 04:40:59 AM
I have a stange voltage drop on the + side right after the W04 bridge. I only get +5.20V. I unsoldered the +15 pin on the left VCA, a 202xt, and suddenly the voltage was right. I've switched places of the two 202xt:s, and the result are the same.
Jakob said that something is shorting out the +15 rail. Does this mean the sorting out is somewhere after the 202xt:s in the chain, or are the vca's broken?
Anyone got any ideas?


/Flundran
Title: SSL HELP THREAD!!!
Post by: gyraf on April 01, 2005, 04:46:40 AM
If one VCA kills the +15V supply when it's soldered in, there's a pretty good chance that that VCA's broken...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 01, 2005, 05:30:07 AM
In that case both are broken. I switched place and the same problem accours..
 :cry:
Title: SSL HELP THREAD!!!
Post by: gyraf on April 01, 2005, 05:55:57 AM
Does It happen with the same VCA soldered in, or with a VCA soldered in the same place?

If it's a place problem, then check the pcb and soldering. If fault follows one of the VCA's, then this is broken..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: FrankSL on April 02, 2005, 04:19:08 PM
Don't know if this has already been noticed, but looking at the pcb I found that the 100R resistors on output are in fact put after the parallel of the 100n and 100u caps, or connected directly at the output terminals.

I don't think this cause problems, but maybe is possible to correct the schem accordingly, just to have it exactly match the pcb...
If I'm wrong please beat me... :grin:

Frank
Title: SSL HELP THREAD!!!
Post by: gyraf on April 02, 2005, 07:01:08 PM
Frank,

You're right - but the order of those dosen't matter...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dukasound on April 03, 2005, 12:53:55 PM
Hi
I will use 2180 instead 2181 what I have now.
Can I use all of three on place 2150 (without trimer on two). Any changings on sidechain if I use 2180?
Thanks
Duka
Title: SSL HELP THREAD!!!
Post by: bubba_b on April 04, 2005, 04:21:54 AM
So I decided to just start yanking parts off the board and test them for good or badness, since I didn't know where the problem was. I knew it was in the left output section, so I started there. I found a couple bad caps (I assumed they were bad since a good one measured about 8megohms and these measured about 1.5megohms and another was in the 30+megohm range). After replacing those caps and tidying up all the other good parts I took out, I fired it up and now it works fine......except. Yes, there's a butt. The meter does not move. The unit functions perfectly, all controls are good, but no meter and it's not hooked up backwards (I thought that and checked). Brand new 1mA meter, too. $18 one.

Thoughts?
Title: SSL HELP THREAD!!!
Post by: Greg on April 04, 2005, 01:37:53 PM
Is it the Modutec meter?
Title: SSL HELP THREAD!!!
Post by: bubba_b on April 04, 2005, 05:17:15 PM
No, it's an edgewise meter made by Shurite, model 350. It's a 1mA. Here (http://www.primetechnology.com/docs/shurite_docs/stanana.pdf) is a pic and spec sheet for it from Prime Technology's website.
Title: SSL HELP THREAD!!!
Post by: gyraf on April 05, 2005, 04:25:48 AM
Bub,

Look at the schematic. The meter is driven from 1/4 TL074, through a 2K resistor. Check that voltage is changing with compression at the output pin of the TL074. Check resistor value. Check continuity all the way to the meter. Check your panelmeter with your ohmmeter (it should move when ohm'ed in the 200Ohms range)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 11, 2005, 11:30:47 AM
A few weeks ago I put togehter my first SSL and found out a had a voltage drop on the +15V rail. Here I got only +3.7V.
Because of various problems with the PCB (bad drilling etc), I decided to move the components to a new PCB. Today I put i all together. Guess what? Same voltage drop at the +15 rail. I still got only +3.7V.

Is it possible the shortout lies on the control pcb?

How do i check a capasitor with a voltmeter?

/Flundran
Title: SSL HELP THREAD!!!
Post by: gyraf on April 11, 2005, 11:38:07 AM
Check that your regulators are alright - cut the connection to the rest of the pcb and mesure. If it measures right, solder a link back on the pcb where you cut it.

If regulators are alright, then there must be something drawing the rail down - a short somewhere, or a broken component (IC).

Try first with no IC's mounted (this is why it's a good idea to use sockets) - and make sure your DC voltages (including the +/-12V) are good.

Then mount the IC's - OBSERVE ORIENTATION! - one at a time, measuring voltages in between - untill you've found what IC that does the mess..

Change that for a new one...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 13, 2005, 11:55:50 AM
Ok, I have sockets to all IC:s and all IC:s has been taken out. I checked the 7815 regulator and did cut the connection to the rest of the PCB and measured it. It shows +10.6V. The 7915 (still soldered) measure -12V

I've tried with a new 7815, with the same result...


I'm really confused. My trafo is a toroid without ground connection.  When a do measurements on the PCB I connect my voltmeter to the pcb ground. Is this the right way?

/F
Title: SSL HELP THREAD!!!
Post by: gyraf on April 13, 2005, 12:32:35 PM
Quote from: "Flundran"
 My trafo is a toroid without ground connection.


What do you mean by that?

You need three wires from the transformer: 15-0-15V AC - that is 30V with a centre tap, also named 2x15V in Europe..

What is the input voltage to your regulators? Measure at the diode bridge..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 13, 2005, 01:29:10 PM
Here is a picture of my toroid connections I just drew:

(http://www.stocksound.se/bilder/toroid.jpg)

I haven't mounted trafo or PCB's in a box yet, I'm still waiting for the box to arrive..

/R
Title: SSL HELP THREAD!!!
Post by: gyraf on April 14, 2005, 02:22:14 AM
Quote
2x15V 30VA gr-re/br-bu


If this is what is actually written on the transformer, then:

Connect red and brown together to connect to the centre point of the power inlet connector on the PCB. Green and blue to the outer pins.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 14, 2005, 08:09:44 AM
Now I've got correct values at all rails, even with IC's on the PCB. Thanks Jakob!
Title: SSL HELP THREAD!!!
Post by: Flundran on April 14, 2005, 12:41:45 PM
I've traced the problem to the 'THRESHOLD' pot.. I have a loud humming noise from the "-" rail it seems... If I turn the 'THRESHOLD' all the way up OR down the signal dies...

 What does this mean?
Title: SSL HELP THREAD!!!
Post by: gyraf on April 14, 2005, 01:04:33 PM
Look at the schematic. Check that the resistors around that pot are right. Check that the pot's centre connection dosen't short to anything. Last, try with a new TL074.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 14, 2005, 06:53:49 PM
I have done some resoldering and this is the situation now:

I get clean signal on both channels. However, there's no compression going on.
When I search for a short-out I use a multi-meter and set it to 'resistance'. Then I connect one node at the PCB ground and the other at the spot I want to check. If the meter read zero resistance, there's a shortcut. Is this the correct way to do?

/Flundran
Title: SSL HELP THREAD!!!
Post by: neilwight on April 14, 2005, 08:27:00 PM
anyone got any codes for the rotary switches they are using in this build, ones for RS would be nice as im probably going to just get almost everything from them here in the UK.

i had thought 665-203 and 665-219 looked correct but can anyone confirm. theres no mention regarding shaft diameter or the likes and ive not received my PCBs yet so cant check pin diameter and number either.
if anyone can advise id be most grateful.

also, anyone got any favourites for the potentiometers? since im ordering online i cant get in to give them a twist for feel.

thanks,
neil
Title: SSL HELP THREAD!!!
Post by: neilwight on April 14, 2005, 09:41:46 PM
couple more questions,

regarding the external sidechain switch on the SSL G series unit.

am i correct in thinking (since i dont have schematics for original) that this cuts CV to sidechain if activated, allowing only external signal to control?

if so am i then correct in thinking that if i wire a switch in between the 100R (sitting directly below 56KR) coming of the TL072 and the input on the 470R that it goes to i will be creating a replica of this function?

also regarding using an external (off board) transformer. im a little confused as to where i attach my two 15v wires and the 0v wire. do these go to the three pins in the top left corner with 0v in the middle and 15v's either side?
where it says "mount these only if external transformer" surely this doesnt mean i link one 15v input to the +  as indicated by arrows does it. is it refering only to the fact that these pins and that piece need only be used if using an external transoformer.
if using this do i still need to insert the same piece at the other side of the two big capacitors also. it appears that it would now be redundant
actually what are these, am i right in thinking its a bridge rectifier?

finally, any guidance regarding current requirements for a toroidal to use, id looked at a 50va with an output of 2x15v, 1.67A. is this overkill, i think im going to fit lit bypass switches as per original. meter is unlit however.

sorry for all the questions but hope you guys can help out.
neil
Title: SSL HELP THREAD!!!
Post by: gyraf on April 15, 2005, 03:18:54 AM
Quote from: "Flundran"
When I search for a short-out I use a multi-meter and set it to 'resistance'. Then I connect one node at the PCB ground and the other at the spot I want to check. If the meter read zero resistance, there's a shortcut. Is this the correct way to do?


Yes. And some meters have a beeper to indicate (close to) zero Ohms.

If you have no compression, but the unit is otherwise working, then check and recheck the wireing of the bypass switch. Compare to schematic while doing this.

Neil,

If you read through all of this thread and/or the SSL Meta, I'm pretty sure you would have all your questions answered...

But to cut it short: All pcb-mounted Lorlin switches will fit the pcb. Pot quality is not important, as they pass DC only, no audio. The sidechain thingy is for sidechain audio - DO NOT MESS WITH THE DC, this messes up compression ratios very easily. The transformer is mounted with three wires, 15-0-15VAC, when using external transformer (not onboard), mount only the bridge rectifier marked for this. Current consumption is some 2x100mA at the most, but a larger transformer allows for good meter light.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: neilwight on April 15, 2005, 06:49:24 AM
jakob,

thank you for taking the time to reply to me.

i had read through this thread over the last couple of days but had still felt a little unsure of my understanding even though some points seemed to have been raised. apologies if it seemed like i was asking to be mothered a little too much, perhaps in hindsight this was actually the case.

i know feel much clearer though and am really keen to get cracking on my first project.

neil
Title: SSL HELP THREAD!!!
Post by: j180ec on April 15, 2005, 01:12:15 PM
Hi. I just finished building the SSL clone and wanted to say thanks to everyone for their input on this project, especially Gyraf for his patience and Gustav for supplying the professional PCB's. This was my first DIY so I had lots of questions. But because of all you kind people, I was able to find all of the answers in these threads. So thanks again for making this project a total success.

Now, to start planning the next project!  Hmmm, I think the Pultec EQ would make a good addition to my rack.

Cheers, John D
Title: SSL HELP THREAD!!!
Post by: dukasound on April 15, 2005, 06:52:34 PM
Hi
I assembled my GSSL and look at this on my bench :grin:
(http://www.dukasound.cg.yu/Data/DSC08051b.JPG)
First, I measured voltages and I have:
+14,94VDC
-15,25VDC :?:  :?
+11,98VDC
-11,98VDC.
I used 2x18V transformer and I saw 22,6VDC after rectifier.
Because I still didnt receive 2180 I put 2181 with modyfing: 1M to 680K, remove 10K and linked with wire.  Also 68ohm is omited. Because I havent any instrument to measure distortion I set trim 50K to measure min voltage on middle who is connected to 680K.
Than I put some music and set ratio 2:1 and if I set high gain reduction the sound wasnt bad. Gain is different in a relation of attack and release
Also I test with sine wave and watch on my mixer VU. If I had full scale reduction I saw on my mixer ?20db. I tested with Make-up on CCW position. If I put Make-up full CW I saw 0db.
This big meter is 1mA. Next I will try to test ratio and maybe S/N.
I havent any hum.
Does anyone knows input and output specification (sensitivity, impedance, etc)?
Thanks to Vili Lampas who send me boards.
Duka
Title: SSL HELP THREAD!!!
Post by: Flundran on April 17, 2005, 01:07:50 AM
I followed the THRESHOLD signal with my multimeter, and it seems the signal is shorted out right after the 220K resistance.

I looked at the SSL schematic and compared with spec. sheet of the tl072. It seemed to me the tl072 should be mounted the other way around. So I did that and powered up. Nothing happend, no voltage anywhere on the PCB.

I've measured my toroid trafo in every way I can think of. It seems that it's broken. Is toroids fragile in general??? I would think the toroid would be the last thing to break...

/Flundran
Title: SSL HELP THREAD!!!
Post by: gyraf on April 17, 2005, 05:42:41 AM
Flundran,

The '072 should be mounted like shown in the layout .PDF and on the component overlay. Mount it wrong, and it dies.

The 220K's goes to the inverting input of TL072. This is a "virtual ground" point, that will always be at 0V because of the feedback resistor. If you have to measure, measure at the opamp output. Nothe that pin numbers for the two opamps in the 072 are swapped on the schematic.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on April 17, 2005, 09:12:01 AM
Quote
Nothe that pin numbers for the two opamps in the 072 are swapped on the schematic.



This is what's been confusing me...


Quote
If you have to measure, measure at the opamp output.


I have to measure on this compressor to find out what's wrong and why it won't work.


/F
Title: SSL clone threshold problem
Post by: super5-56 on April 18, 2005, 02:39:30 PM
Hi everybody and thanks for a great place!

I´m about to finish my first DIY project, and except for a bug with the threshold control and a minor ground hum, I´m quite happy with myself''

The problem is that the threshold control doesn´t affect the signal at all. The unit is compressing very nice, but the compression is starting when I feed 0.1v into it and when I reach nominal level at .775v I can barely recognize the input signal anymore. I have read about every post around here, and have tried to swap VCA´s, 072 and 074 without any sucsess. The values at the Threshold pot are like they´re supposed to be, and all the power rails show decent values(+15.2, -15.2, +11.97, -12.21).
I have also measured a lot of resistors and looked all over the PCB´s with magnifying-glass for shorts or cold joints but I haven´t had sucsess so far.
So... any bright ideas at where to look?


thanks
/kjt
Title: SSL HELP THREAD!!!
Post by: gyraf on April 19, 2005, 02:10:30 AM
KJT,

Look at the schematic. The threshold pot is a voltage divider that adds a DC voltage to the control voltage going to the sidechain VCA.

The 50K threshold pot is connected between +12V and -12V. So you should have a voltage at point "F" that can be varied from +12 to -12 by turning the threshold pot. Next is the 220K resistor that mixes (adds) this voltage with the CV that comes from the timing circuit, and controls the sidechain VCA.

Try tracking these voltages. Note that pin numbering for the TL072 is swapped on the schematic relative to the PCB.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: super5-56 on April 21, 2005, 02:37:07 AM
Hi an thanks.

I´ve checked the +/-12v at point "F" and also at the 220k resistor and can´t find anything suspecios. But at the other side at the 220k I have next to nothing regardless position of the threshold control. Is this right?
I have of course lifted one of its legs, and I measure it to be 218k.
I have also checked the PCB´S for shorts with my meter, but are not doing any progress.
I happend to put my finger at the left corner backside(Resistors 1M2+1M8 and the other beneath+ the threshold pot wiring points) of the control PCB, and I suddenly got some action on the threshold pot.
Think I have put in the right values on components and really don´t know where to look now:-(


/kjtl
Title: SSL HELP THREAD!!!
Post by: gyraf on April 21, 2005, 02:54:27 AM
Quote from: "super5-56"
But at the other side at the 220k I have next to nothing regardless position of the threshold control. Is this right?


Yes, it's right. You're measuring at the input of a virtual-ground summer. The feedback resistor will make sure that the inverting input is at the same voltage as the non-inverting input - which is grounded.

Measure at the output of the 072 opamp to get useable results.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: super5-56 on April 21, 2005, 05:42:09 PM
Quote from: "gyraf"

Try tracking these voltages. Note that pin numbering for the TL072 is swapped on the schematic relative to the PCB.


:green:

Tracking was the thing. I had populated with a 470K instead of 470R and will probably need glasses before I start another project ':oops:'

Thanks for all your help, now I just have to trace the minor 50hz hum.

/Kjtl
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on April 26, 2005, 09:00:25 AM
Hi all, finished populating my GSSL Board (thanks Jakob fort the project, Gustav fort his quality PCBs) and measured and tested the boards the last three days. Passes audio, sounds great, measuring is good for just a PCB with no housing.

But I have problem / question according the Threshold settings: setting Threshold to 0dB (disconnecting the wiper of the Pod), feeding 0 dBu to one channel (avoiding the addition of coherent sinus signals) I have 14 dB gain reduction. I could fix this modifying the Threshold Pot, but I don?t think this is normal, and I want to understand where my fault is. I checked components, shorts etc for three days now, and I can?t find anything.

It would be interesting what you people measure at some points on your units, because I have some strange values I don?t understand: TL074, Pin 14 (feeding 1kHz @ 0 dBu, Threshold at 0dB) I measure -7,55V in Bypass, -0,93V when switched in. TL074 Pin 10 = -1,69V (unit switched in).

Any experience with your unit or hints would be interesting. I read all 41! Pages of this thread with no result according my problem ? and while I think I have a problem the unit sounds still great!
 :grin:
Title: SSL HELP THREAD!!!
Post by: gyraf on April 26, 2005, 09:12:45 AM
Hi [Silent],

The threshold function in the SSL is threefold:

First, there is the voltage added to the rectified control-voltage by one-half of the ratio switch. This is because the designers wanted to acheive more-or-less the same GR when switching ratios - providing that your mixbus was loaded to around 0dB. We keep this artefact in the clone - just as we keep just about everything else in this well-proven design..

Second, there's the voltage drop of the 1N4148 between TL074 pin14 and Point"C". This is the actual threshold that has to be overcome in order to start compressing.

Third, there's the gain of the sidechain VCA, that is set by adding a voltage from the threshold pot with the actual "feedback" voltage coming from the rectifier.

In all, I think your voltages are in the right range - allthough I don't currently have a prototype to measure exact voltages on..

TL074 pin14 in bypass has no "feedback" path, as the connection between the rectifier and the timing is interrupted by the bypass switch - so wierd sidechain voltages when bypassed is natural, and not necessarily out of order.

Anyone else with an open clone?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on April 26, 2005, 09:31:44 AM
Hi Jakob - this was fast ...

ok, the voltage drop (same conditions, 1kHz @ 0dBu, one channel): I have -0,93V at pin14, -1,69V @ point "C". (is this a drop ???)

I think I have too much gain in the sidechain VCA.
Title: SSL HELP THREAD!!!
Post by: gyraf on April 26, 2005, 09:41:16 AM
Too much gain in the sidechain VCA will show very easily as a ratio that goes beyond 10:1 - often even beyond inf:1, meaning that raised input level will diminish output level. So it's an easy test to do to confirm that everything is alright...

Jakob E.
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on April 26, 2005, 12:41:29 PM
At 10:1 I have a ratio beyond inf:1 (+2dB input dimish 0,2dB output). because of the "SSL ratio measuring" thread I thought I will fix this later that way, but may be it's part of my threshold problem.
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on April 27, 2005, 06:06:20 AM
OK, I fixed the Ratios with Steffens solution. Now I have exactly 1:1.95, 1:4.1 and 1:10.

I think my Threshold is still too low, with wiper disconnected the 1:10 comprression starts at -14dBu input @ one channel.

BUT the compression curves have their crosspoint at ca 0dBu Input. Is this ment to be the Threshold ???

Anyway, I just ordered two other PCB sets to compare. If this is normal I will have to mod the Threshold to start from 0 to + 20dB.
Title: SSL HELP THREAD!!!
Post by: gyraf on April 27, 2005, 06:11:22 AM
I think it's normal behaviour - but if you like, the threshold is easily altered by either changing the series resistor and/or adding a resistor at one of the pot's ends..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on April 27, 2005, 07:54:10 AM
Thanks Jakob.

I think my understanding of Threshold is maybe different from the one SLL uses. But just like "MakeUp" or "Gain", it's just labeling. And for a bus compressor it may even makes sense the way it is.
Title: SSL HELP THREAD!!!
Post by: cannikin on April 27, 2005, 01:51:18 PM
Hey Guys; Well my GSSL is up and running...

THe right channel is working perfectly.. actually sounds amazing!

THe problem I'm getting no Signal through the right channel.  I have checked my solder looking for bad joints solder bridges and incorrect wiring but can't find anything...

Where - what should I look for next....

Help!
Title: SSL HELP THREAD!!!
Post by: gyraf on April 27, 2005, 01:57:37 PM
Same procedure as described several times before..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: chrissugar on April 27, 2005, 02:11:53 PM
Hey cannikin

I wrote a step by step description about how to isolate the problem in two threads, one for Hulk and one for J Hall.
Find those threads and try to do those tests.

chrissugar
Title: SSL HELP THREAD!!!
Post by: chrissugar on April 27, 2005, 02:15:31 PM
This is the thread:
http://www.groupdiy.com/index.php?topic=6338&start=0&postdays=0&postorder=asc&highlight=

chrissugar
Title: SSL HELP THREAD!!!
Post by: cannikin on April 27, 2005, 02:16:05 PM
Thanks Chris!
Title: SSL HELP THREAD!!!
Post by: cannikin on April 27, 2005, 02:48:45 PM
Ok here are my readings with only the 5334's in:

Pin 7  =  -15.00 dcV
Pin 6  =   -0.01
Pin 4  =  15.06

Its the exact opposite?????
Title: SSL HELP THREAD!!!
Post by: chrissugar on April 27, 2005, 05:22:19 PM
Are you sure you didn't reverse the cables from your multimeter.
When you measure voltages you should connect the multimeter COM or Ground to the PSU ground from the SSL comp and measure the voltage you mentioned with the other cable of the multimeter.
What was your ground point on your SSL?

As long as one channel works ok, it is impossible to have reversed voltages.
Check again.

chrissugar
Title: SSL HELP THREAD!!!
Post by: cannikin on April 27, 2005, 06:16:28 PM
Thats exactly what I did.  ANyway the good news is all the voltages are correct, I found the "no SOund in Left issue" it was just an over looked bad solder joint.  Its all working.. thanks for all your help.   I'm sure I'll have a few more questions in the future... but Its running.

 :grin: Cheers Chris
Title: SSL HELP THREAD!!!
Post by: gyraf on April 28, 2005, 02:25:45 AM
Quote from: "cannikin"
..it was just an over looked bad solder joint.  Its all working..


As I said: "Same procedure as described several times before.. "

 :razz:

Congrats on finishing the unit, Canni!  :thumb:

Jakob E.
Title: SSL HELP THREAD!!!
Post by: cannikin on April 28, 2005, 12:09:08 PM
Thanks everyone!  Especially Jakob
Title: SSL HELP THREAD!!!
Post by: gyraf on April 28, 2005, 12:10:40 PM
Looks really well with that meter..!  :thumb:
Title: SSL HELP THREAD!!!
Post by: radiance on April 28, 2005, 01:42:18 PM
Very nice!
I see a lot off people using this IEC power connector. Does this has some kind off power conditioner inside or is it extra shielded?
Title: SSL HELP THREAD!!!
Post by: chrissugar on April 28, 2005, 04:38:11 PM
Hey cannikin,

I'm glad you solved the problem very quick.
Very nice looking box. That meter is sooo lovely. Where can I find them?

chrissugar
Title: SSL HELP THREAD!!!
Post by: Svart on April 28, 2005, 04:41:11 PM
i also have to say "that's a cool meter!"

and usually that IEC connector will have some kind of filter or TVS setup in it.  depends on the model and how much it lightens your wallet as to what features it has..  :green:
Title: SSL HELP THREAD!!!
Post by: cannikin on April 28, 2005, 04:53:30 PM
Thanks Guys!

The Meter is a Phastron

-24 dBm to Infinity
(MTR) 618-20025
Phastron level meter in popular 1-3/4" square case. 1-1/2" mount hole, 1-1/4" behind panel. Sealed.

Found Here: http://www.surplussales.com/Meters/MtrVU.html

The meter has great tracking... Its cool :thumb:

The IEC  is Mouser Part # 562-857-03/17
IEC Conn/Filter 3A, Qualtek RFI Powerline Filters.

The Hamptone Mic Pre uses these IEC and when I started ordering Parts I had no idea which IEC to get, so I just went with something that I already knew about.   They're about 4.50 a pop.
Title: SSL HELP THREAD!!!
Post by: gyraf on April 29, 2005, 03:25:19 AM
David,

Just in case that you get hum or buzz in your clone, you should know that power inlets with integrated noise filters are notorious at being sources of noise in audio units, unless your power outlet is properly grounded.

This because the inlet filters include two capacitors, one from each live to ground. In case of poor grounding, one of these may let through unwanted line noise, that ends up in your Localground/0V

If you experience noise in the clone, try with a no-filter power inlet.

Jakob E.
Title: power on problem
Post by: mattlord on April 29, 2005, 11:05:01 PM
hi!
having a problem with both of the g-ssl's i have built recently which i think is something to do with the power-on led that i have wired directly to one of the 15v secondaries of the power transformer (via a resistor)... both units work absolutely as they should do, and sound great, but occasionally when you turn them on something weird happens - the power led doesnt light, the meter led lights up but is extremely dim. no sound will pass and the meter goes up to half-scale and stays there... as soon as you turn the unit off then on again, everything is fine. it's an annoying little problem which seems to happen about every one in ten times the unit is switched on - not a major problem but if anyone's got any ideas for a fix i would be extremely grateful for any help. thanks again to jakob for an amazing project and thanks to chef for the pcbs! DIY FOREVER!
Title: SSL HELP THREAD!!!
Post by: cannikin on April 29, 2005, 11:15:39 PM
Thanks for tip Gyraf.
Title: power on problem
Post by: mattlord on April 30, 2005, 12:17:56 AM
:oops:  :oops:    ahem, sorry about the post above, please ignore!! just re-read the whole of the thread and found the answer - latching regulator.. will change the offending part... hope that sorts the problem!! once again apologies - should've read more carefully!!!
Title: SSL HELP THREAD!!!
Post by: yan_b on April 30, 2005, 03:12:21 PM
well i encountered similar problem or so i tought, after 15 min that my ssl was working properly, the led turned off and the meter went all the way up.
now since i read the tred i checked the volts and saw that 12 + droped to 6 v
changing the 78l12 fix that matter, but it seems that there is some short cuircit cuase the the 78l12 heats up, the meter still pegs when not in bypass mode.
i coul not find any short cuircit (even with measuring), also changed tl074, and tl072,and  checked voltage in vcc-+ pins.

now to wich parts of the cuircit i can limit my problem?
Title: SSL HELP THREAD!!!
Post by: yan_b on May 01, 2005, 02:33:34 PM
ok more updates.
the side chain vca died on me,when  replaced with one off the audio path vca ,  the circuit works fine (for now).

the regulator 78l12 keep heating up especially when i install tl072, i measured current (only for the 78l12 output) with and without the tl072, it's 36/22 ma wich seems fine and with in the regulator spec's, i should mention that the 79l12 stays cool.

now what essential checks can i make befor installng new side chain vca exept vcc +-?, i do not want to burn another one  :sad: .
any ideas about the regulator heating will be welcomed too (another defective part?)
Title: SSL HELP THREAD!!!
Post by: gyraf on May 01, 2005, 02:45:06 PM
As always - check for correct components and shorts..  :?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: cannikin on May 09, 2005, 04:14:51 PM
Hey Jakob;

I'm building my second GSSL, my friend stole the one I just finished (he liked it too much).  anyway I was wondering if it would be OK to use
1000uf 63v  instead  of 1000uf 35v?

from what You've written before in other threads Voltage values listed in the BOM are a minimum. But I just want to double check.

Thanks.
Title: SSL HELP THREAD!!!
Post by: radiance on May 09, 2005, 06:26:32 PM
Well, I'm not Jakob but let me answer your question. Yes, 63v will do. Just make sure they're not too BIG.
Title: SSL HELP THREAD!!!
Post by: drpat on May 12, 2005, 08:20:23 AM
...
Title: SSL HELP THREAD!!!
Post by: gyraf on May 12, 2005, 08:39:22 AM
Don't worry about that - it's a minor schematic error.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mike_relay on May 12, 2005, 11:51:06 AM
do the .1mfd caps need to me metalized polyester? or can they be ceramics?
thanks,
mike
Title: SSL HELP THREAD!!!
Post by: drpat on May 12, 2005, 04:19:18 PM
...
Title: SSL HELP THREAD!!!
Post by: drpat on May 12, 2005, 06:15:53 PM
...
Title: distortion in bypass
Post by: Nele on May 15, 2005, 09:36:39 AM
Hi,

I've noticed that my ssl-unit is distorting in bypass-mode. it is hooked up directly to my RME-multiface. could the output-levels of the multiface be too high or is something wrong?

thanks!
corneel
Title: SSL HELP THREAD!!!
Post by: on May 15, 2005, 01:27:20 PM
I'm having some meter problems.  I read through the first 25 pages or so, but didn't see anything about this.  If I understand some of the other posts about pegged meters, the meter STAYS at the top of the scale, which mine isn't doing.  But maybe it's the same problem?  With no audio, when I turn the threshhold knob, my sifam meter goes all the way to the top of the scale, and then settles back down to 0.  That happens if I turn the knob all the way up or all the way down.  If I turn it somewhere in the middle, it usually jumps to the top and settles somewhere in the middle of the scale.  My pot is not the right one, however.  I used Greg's US parts list and got the 50K pot on there (Digikey, CT2207-ND), but the bushing and shaft are the wrong size.  The value is right, though, so I wouldn't think that would be a problem.  Anybody have an idea of what it might be?  I've checked my soldering and it looks good.



David.
Title: Re: distortion in bypass
Post by: digichild on May 15, 2005, 02:58:12 PM
Quote from: "Nele"
Hi,

I've noticed that my ssl-unit is distorting in bypass-mode. it is hooked up directly to my RME-multiface. could the output-levels of the multiface be too high or is something wrong?

thanks!
corneel


i had the same problem...try to adjust your rme card,if it has jumpers fot the levels...otherwise-which sequencer do you use?if you have logic you could adjust the levels inside the helper plugin
Title: SSL HELP THREAD!!!
Post by: Coldsnow on May 16, 2005, 10:19:51 PM
HI all.  I built another GSSL and the sidechain (no compression) is not working.   The voltages look good I think.  The weird thing is that quite a few resisters on the sidechain section have changed values since they have been put in the board:
3M3 is now .63ohm
1M is now 293K
10K is now 47ohm (the one next to the other two 47R resisters)
100K is now 64K
the four together
220K is now 42K
100K is now 70K
620K is now 70K
100K is now 70K
Any ideas what is going on?
The resisters in the power and channel sections all seem to shake out well.
Title: SSL HELP THREAD!!!
Post by: digichild on May 17, 2005, 01:38:51 AM
Quote from: "Coldsnow"
HI all.  I built another GSSL and the sidechain (no compression) is not working.   The voltages look good I think.  The weird thing is that quite a few resisters on the sidechain section have changed values since they have been put in the board:
3M3 is now .63ohm
1M is now 293K
10K is now 47ohm (the one next to the other two 47R resisters)
100K is now 64K
the four together
220K is now 42K
100K is now 70K
620K is now 70K
100K is now 70K
Any ideas what is going on?
The resisters in the power and channel sections all seem to shake out well.
if you have measured the resistors on the board,then its clear that they dont have the same values anymore ...you shoud check the colourcode to make sure that you put in the right types...you can try this link:http://www.elexp.com/t_resist.htm...also check your board for shorts very carefully :grin:
Title: SSL HELP THREAD!!!
Post by: gyraf on May 17, 2005, 03:49:53 AM
Remember that you can't measure resistors in-circuit to any degree of precision - other components will load them. You need to unsolder and lift one end of them to measure.

And measuring with power on gives even more deviation from real value..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dufo on May 17, 2005, 04:33:23 AM
Quote from: "twitchmonitor"
I'm having some meter problems.  I read through the first 25 pages or so, but didn't see anything about this.  If I understand some of the other posts about pegged meters, the meter STAYS at the top of the scale, which mine isn't doing.  But maybe it's the same problem?  With no audio, when I turn the threshhold knob, my sifam meter goes all the way to the top of the scale, and then settles back down to 0.  That happens if I turn the knob all the way up or all the way down.  If I turn it somewhere in the middle, it usually jumps to the top and settles somewhere in the middle of the scale.  My pot is not the right one, however.  I used Greg's US parts list and got the 50K pot on there (Digikey, CT2207-ND), but the bushing and shaft are the wrong size.  The value is right, though, so I wouldn't think that would be a problem.  Anybody have an idea of what it might be?  I've checked my soldering and it looks good.


I have the same problem. I am using the right pots. I got no idea what it could be though...


David.
Title: SSL HELP THREAD!!!
Post by: radiance on May 17, 2005, 10:15:00 AM
Quote from: "dufo"
Quote from: "twitchmonitor"
I'm having some meter problems.  I read through the first 25 pages or so, but didn't see anything about this.  If I understand some of the other posts about pegged meters, the meter STAYS at the top of the scale, which mine isn't doing.  But maybe it's the same problem?  With no audio, when I turn the threshhold knob, my sifam meter goes all the way to the top of the scale, and then settles back down to 0.  That happens if I turn the knob all the way up or all the way down.  If I turn it somewhere in the middle, it usually jumps to the top and settles somewhere in the middle of the scale.  My pot is not the right one, however.  I used Greg's US parts list and got the 50K pot on there (Digikey, CT2207-ND), but the bushing and shaft are the wrong size.  The value is right, though, so I wouldn't think that would be a problem.  Anybody have an idea of what it might be?  I've checked my soldering and it looks good.


I have the same problem. I am using the right pots. I got no idea what it could be though...


David.

 :?
Title: SSL HELP THREAD!!!
Post by: rrs on May 28, 2005, 10:41:53 AM
Hi this is my first DIY project (GSSL) an first post on this forum. I have got all the parts I need including a Toroidal 15+15V Transformer part MT2086 from Jaycar here in Australia.
My question is basicaly where to connect the wires. I did a search and found this question addressed but still have questions. http://www.groupdiy.com/index.php?topic=4924&highlight=toroidal+transformer+15v015v+20va
It was stated here that red and white were the centre tap, yellow and purple 15V and the two Orange go to wall socket.There seem to be two places to put these on the board and as I have already put the bridge to the centre of the PCB I guess going of pic's I've seen I should connect transformer wires closer to it and not in corner where it says (mount if external transformer)
Anyway if this is where I am going to put them what goes where?Where does the centre tap go?I seem to have 4 holes to place the 4 different wires but still don't know where they go on the board.
This may be basic to you guys but I am a beginner and know very little but am willing to learn.  :green:
Title: SSL HELP THREAD!!!
Post by: radiance on May 28, 2005, 11:11:25 AM
First off all, check the data sheet off your toroid transformer just in case...
About the wires: Yes, you're right. Since you soldered the bridge rectefier where you did, you should use the four holes intended for the small transformer (on the pcb). The center tap goes to the two middle holes (holes 2 and 3)and one +15 tap goes to hole 1, and the other +15 tap goes to hole 4.
To make sure everything is wired correct have a close look at the pcb.
The two center tap holes (hole 2 and 3) are connected to eachother and to the ground plane off the pcb.
Now follow the two +15 leads. The should both be connected  too the AC leads (~)off your bridge rectefier.
Title: SSL HELP THREAD!!!
Post by: rrs on May 28, 2005, 08:20:03 PM
Thanx radiance now I know where they go on the board  :grin: unfortunetly the transformer from jaycar comes with no information not even on their web site.
The information I am going off is from a similar question posted on this site saying

Yellow=0V
Red=+V

White=0V
Purple=+V

So is red and purple +15?
Does anybody know where I can get info on Toroidal 15 + 15 20V on the web.
Help appreciated. :green:
Title: SSL HELP THREAD!!!
Post by: dirk666 on May 28, 2005, 09:25:21 PM
My ssl type is almost complete, all I have to do is the power supply.

local voltage is 230V 50Hz(New Zealand)

The transformer I got from RS is 347-2565
This should work?

somethings I dont unerstand
0-18V -understand
2,5VA -understand
0,125AT? -this is the magnemotive force(ampere-turns, At)?
VC? 5,0/2/18 ???


I just worked out how to wire up the ac inlet (10A fuse)but which wires go from there to which pins on the primary?

Am sticking with the onboard mounting way.

Cheers, any help graceously accepted.
Title: SSL HELP THREAD!!!
Post by: rrs on May 29, 2005, 03:00:53 AM
HMmmmmmmm

All wired up tripple checked for shorts VCA's right way arround caps and diodes as well have used Jaycar list for parts that Kev Ross has kindly provided but have used different brand caps (same value )from RS here in Australia.
Turned on power and smoke came billowing out of the two NE5534ap in the VCA section.

WHAT HAVE I DONE!!!!!!!!!!!!!

HELP PLEASE.
Title: SSL HELP THREAD!!!
Post by: radiance on May 29, 2005, 07:33:54 AM
Quote from: "rrs"
HMmmmmmmm

All wired up tripple checked for shorts VCA's right way arround caps and diodes as well have used Jaycar list for parts that Kev Ross has kindly provided but have used different brand caps (same value )from RS here in Australia.
Turned on power and smoke came billowing out of the two NE5534ap in the VCA section.

WHAT HAVE I DONE!!!!!!!!!!!!!

HELP PLEASE.


Next time, take out all IC's (also the VCA's) before powering up. Then power up and check if all voltages are correct and next check whether the IC's are getting the right voltages or not.
Title: SSL HELP THREAD!!!
Post by: mnats on May 29, 2005, 08:37:42 AM
Quote from: "radiance"
one +15 tap goes to hole 1, and the other +15 tap goes to hole 4.

Quote from: "rrs"
So is red and purple +15?

Hopefully you didn't hook them up this way.

The transformer you have doesn't have a center tap, just two similar windings for the secondary voltages, each delivering nominally 15 volts. You tie them together in series to create a "center tap" just as you stated in an earlier post by tying red and white together (or in your case soldering them to the two middle holes as radiance suggested).

If you hook up red and purple to the outside pads it won't work. Solder the yellow wire to one of the pads that goes to the bridge rectifier. Solder the red and white wires to the middle pads that are connected to each other and to ground. Solder the purple wire to the remaining pad that goes to the other side of the bridge.

I think the reason no data comes with the transformer is that all the info you need is printed on the side of the transformer itself. But the 2005 paper catalog has a diagram on page 131.
Title: SSL HELP THREAD!!!
Post by: rrs on May 29, 2005, 11:08:10 AM
OK wired as MNATS has suggested.Oh buy the way had NE5534's wrong way arround. :oops: .Checked voltages Pin 4 =-15.Pin 6=+15 but on right VCA SIDE pin's 2 and 7 are showing -3  ???????
Is this allright.
Title: SSL HELP THREAD!!!
Post by: rrs on May 30, 2005, 08:26:02 AM
OK have put in new NE5534's right way.No smoke ran audio through meter working and controls led and bypass as well BUT no audio out.DEAD SILENCE.
Come on guys Im almost there. :?:  :?:  :?:
Title: SSL HELP THREAD!!!
Post by: radiance on May 30, 2005, 08:59:29 AM
Quote from: "rrs"
........
Come on guys Im almost there. :?:  :?:  :?:


There are many "ssl troubleshoot" threads to be found on this forum.
For example  this one  (http://www.groupdiy.com/index.php?topic=6338&start=0&postdays=0&postorder=asc&highlight=), wherein Chrissugar gives a "kick ass" explanation off how too......
Title: SSL HELP THREAD!!!
Post by: Jonathan Hayward on May 30, 2005, 09:48:37 AM
rrs, I did the same as you with the 5534s some time ago :oops:
I had in fact fried the channel VCAs too, there's a good chance you have too,tp find out, I think you can swap the sidechain VCA into a channel, it should then pass audio.
Title: SSL HELP THREAD!!!
Post by: neilwight on June 03, 2005, 05:39:58 PM
just a couple of questions.

"question removed due to stupidity, spent ages looking for resistor spec to show 10db on a 1ma meter, couldnt find and posted but its on schematic.....doh. 1k will be the answer)

secondly...how do i get the 0.1 caps to fit. just bend the legs in, these things are pretty wide compared to the hole spacings...or did i just screw up my specs.

thirdly...for connecting my toroid...do i just connect the 2 0v wires coming off together and attach to the center hole with the two remaining 15v feeds going to the holes on either side. may seem a bit stupid but i just want to check....the stupid thing would be to not ask and blow it all up  :oops:
Title: SSL HELP THREAD!!!
Post by: mnats on June 04, 2005, 12:13:14 AM
The question of how to wire a specific toroid has come up again and again so I'm going to attempt to give some generic instructions that can be adapted for any power transformer.

There doesn't seem to be any standard for colors but usually there will be a symbol somewhere that roughly corresponds to the one in my diagram below (click on it for a clearer view):

(http://img.photobucket.com/albums/v295/mnats/wiring_toroid.gif)
Sometimes the secondary windings on the right side will have markings like 0 - 15 which to me are misleading since we're referring to AC voltages but whatever. The thing you have to do is find the two secondary wires that are closest together in the diagram. Connect these two together. These form the ground, earth, "0" or in the case of the SSL project the center terminal for the "EXTERNAL AC IN" on Jakob's pdf.

The two transformer secondary leads that are furthest apart on the schematic connect to the bridge rectifier which in the case of the SSL are the two outer pads of the "EXTERNAL AC IN" on Jakob's pdf. It doesn't matter which of the two you connect to which pad but you must connect only one wire to each point!

I think some people might expect to see instructions included with their toroidal transformers telling them how to hook them up. There are a few different ways to hook up a power transformer depending on what you are trying to acheive with it so it would be impossible for the manufacturer to tell you how to hook it up without knowing the application.

Hope that helps.

neilwight: there are zillions of different types of .1uF capacitors with different lead spacings. Use a pair of needle nose pliers and bend the leads to fit, making sure you don't stress the lead near the body of the cap (it might break or weaken). And no, you shouldn't hook the two toroid leads marked 0V together for the SSL but rather follow the instructions above.
Title: SSL HELP THREAD!!!
Post by: dirk666 on June 04, 2005, 03:41:30 AM
umm... :oops:

If I pluged my semiconductors in, then soldered the dil sockets in...fried?

I think I did this but I cant remember to which ones if any

 So do I;

A -  throw my circuitboard across the room, put on some leonard cohen and sulk into my bedroom

B -  ask nicely how to check if said components work  :grin:


ive got  all the data sheets for  Tl072 TL074  5534 5532 and VCA's  but if anyone wanted to point my in the right direction I would be most gratefull
 cheers
Title: SSL HELP THREAD!!!
Post by: radiance on June 04, 2005, 06:32:33 AM
The data sheet off the NE5532 AP sais:

"Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds = 260°C"

In your case you had the IC fitted in a DIL socket which will take away some more soldering heat.
I don't know how your soldering skills are but 10 seconds is pretty darn long so I guess you don't have to worry to much about frying....
Title: SSL HELP THREAD!!!
Post by: rrs on June 04, 2005, 06:38:18 AM
Know the feeling dirk666
I've picked up a couple more VCA's (thanx kev) to replace the ones I destroid during the 5534 incident and now all is working well.
Thanx mnats for the wiring guide.
Title: SSL HELP THREAD!!!
Post by: dirk666 on June 04, 2005, 03:28:16 PM
Well I always solder with my fingers crossed so maybe its ok

 :wink:
Title: SSL HELP THREAD!!!
Post by: neilwight on June 05, 2005, 07:46:53 PM
thanks for that mnatts.

it was really helpful.....until i re-read. sorry to sound like a moron but can you clear one last thing up.

my toroid diagram is thus:

230v----------] [----------------Vsec
                    ] [
                    ] [----------------0 V
                    ] [----------------Vsec
                    ] [
0v------------ ] [----------------0 V

(the formatting messed it up, all   ] [   should line up FYI)

from my reading of your explanation, i should connect the middle 0V and Vsec together and solder to the middle imput on the PCB power in. the remaining (outer) Vsec and the 0V go to the other two solder points respectively.

my (limited ) instinct tells me that this doesnt make sense and that surely the two 0V's go to the centre solder point and the two Vsec go to each remaing point giving two 15v feeds into the PCB..
if this is not the case, can you please (or anyone) explain why. id quite like to understand whats going on for other projects if i last through this so that hopefully i need to ask fewer Qs.
Title: SSL HELP THREAD!!!
Post by: mnats on June 05, 2005, 08:04:04 PM
It occurred to me why they put those voltage markings on the secondaries even though they are AC voltages and thus are constantly varying from positive to negative.

Think of the 0V and Positive (12, 15, 18...)V as instantaneous voltages. You want to add the two voltages together. If you had two 1.5V cells, how do you add the two to create 3V? Answer: By connecting them in series.

Bring this over to the transformer - if you connect the two 0V leads what are you actually doing? Answer: connecting them in parallel.

You want them in series.

My ASCII graphic skills are not as good as yours and I'm late for work but if you follow the guide I posted earlier it will work just fine. If you want proof, just leave out all your active components (except for the ones in the power supply) and power it up. Check your voltages with your DMM. Now wire it your way and try again.
Title: SSL HELP THREAD!!!
Post by: neilwight on June 06, 2005, 02:27:59 PM
thanks for the explanation...

it was this very thinking that was throwing me off the trail a little but due to my lack of full comprehension it now seems.

i was thinking that by adding together on top as per your recommendations it would be more than the board needed....

thanks for pointing me in the right direction  :oops:

neil
Title: SSL HELP THREAD!!!
Post by: dirk666 on June 07, 2005, 07:25:22 PM
Does anybody have NE5532 AP op amps in there unit?

just ordering for my second( and third) ssls and my surplier RS has discontinued the N versions which i used in the first unit i built

the AP is 'designed to be interchangable with 5532A'
but the N type is 'internaly compensated for unity gain'
Title: SSL HELP THREAD!!!
Post by: gyraf on June 08, 2005, 03:47:42 AM
All 5532's are internally compensated, I think. I doubt that exact type or manufacturer makes any difference in a low-gain application like the Clone.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: on June 08, 2005, 08:57:30 PM
Thanks to all the very, very cool people on this forum, my ssl works great.  In fact, I can't believe how good it sounds.  The only "issue" I'm having is that when I turn the "release" knob, there is an audible click (in the audio itself) at each position.  Is anybody else getting that?  I can live with it....it's just odd.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 09, 2005, 03:06:38 AM
..that's completely normal. you shouldn't switch with live audio anyway..
Title: SSL HELP THREAD!!!
Post by: dirk666 on June 09, 2005, 04:13:28 AM
I get the same thing man.
its like a jump in in audio vol for half a second as you turn the knob. nothing to worry about I guess. Not the sort of thing you adjust in the middle of a take.
Title: SSL HELP THREAD!!!
Post by: dirk666 on June 09, 2005, 05:23:24 AM
can somone remind me what the pitch is for the holes for the risistors on the graf boards?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 09, 2005, 05:44:39 AM
It's Gyraf - and they're 4/10" - that's around 10.16mm
Title: SSL HELP THREAD!!!
Post by: neilwight on June 10, 2005, 09:07:43 PM
just finishing off the front panel design for my SSL but have noticed on many of the pics on here of peoples units that their threshold goes from -15db to 15db and gain is from 0 to 15.

my pdf of the PCB shows these figures as being -20 to 20 and 0-20 respectively.

am i missing something or are the differing PCB designs carrying different values here?
Title: SSL HELP THREAD!!!
Post by: Lowfreq on June 13, 2005, 10:21:20 PM
Hi Everyone

I'm another newbie who's started building the GSSL clone, with
a few questions. I have had a quick look through the META's, but
it would be really appreciated if someone could point me in the
right direction/link etc

I have just finshed soldering most of the components onto the
board and everything seems to be progressing quite nicely. :grin:
I'm about to place an order for my vca's and while i'm waiting for
them to arrive i want to start looking at getting my power transformer
up and running.

Now for the questions
1. Should I use the Farnell 976635(2x 18v, 4.5VA 0.13A)
    as written on the Gyraf Board,
    or the RS 201-7038(2 x 15v, 6VA, 0.2A)
    as i think Kev used on his instruction page? Do they have any
    effect on performance, or none that i'd notice?
2. I know that the farnell unit is the bare minimum and i wont have
    enough juice to run a meter light, is the 0.2A RS unit gonna be the
    same? or will it have enough xtra to spare.
3. If i go for the RS unit which has an external PCB, what sort of PCB
    do i go for? Do i have to etch my own? Or use a different
    type  of PCB?
    I understand the theory behind the series/parallel idea for
    110/220v, but have had no luck finding out about the PCB itself.    

Any help is greatly appreciated. I've got my head around most of it,
just those little things stump be sometimes.

Cheers
Steve
Title: SSL HELP THREAD!!!
Post by: gyraf on June 14, 2005, 02:38:09 AM
Hi Steve,

Welcome to The Lab..

If you use on-board transformers, you won't have spare power for a meter light. This is why most people build this unit with power transformer mounted off-board.

The easiest and most quiet will be a toroid power transformer - you'll need 2x15V or 2x18V secondary at some 10-20VA. Then you'll have a couple of watts or so for meter illumination without annoying the important parts.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on June 17, 2005, 12:43:42 PM
Hi All...

Posted this querry over on tube jay's "ssl north american parts" thread, so forgive the repetition, but am in need of advice badly on the Lorlin Switch choices...there seem to be conflicting suggestions about which ones to use.

I am using Gustav's board and have gathered all the other parts described on the lists with the exception of these switches :sad:

Can anyone help?

Greg's Mouser List suggest:

-10WA137 (4X3)and 10WA135(2X6)... are both listed at mouser as "NON   SHORTING (brake before make)" variety and both with "p.c. terminals" and "D shaft"
-10WA167(4X3)... is listed the same, but with "solder terminals"


Others Parts Lists here suggest;

-10WA367(4X3) and 10WA365 (2X6)....both listed at mouser as being "SHORTING (make before brake) variety and both with solder terminals and "flat shaft"

ARE THESE DIFFERENCES SIGNIFICANT?

MOUSER IS CURRENTLY OUT OF STOCK OF THE 10WA135.

COULD 10WA365 SUBSTITUTE FOR 135?

any clarity appreciated
t. :shock:
Title: SSL HELP THREAD!!!
Post by: gyraf on June 17, 2005, 12:45:57 PM
Quote
ARE THESE DIFFERENCES SIGNIFICANT?


no
Title: SSL HELP THREAD!!!
Post by: mike_relay on June 17, 2005, 12:48:59 PM
Quote from: "gyraf"
It's Gyraf


let me just say I love you logo!  :grin:
Title: SSL HELP THREAD!!!
Post by: tree on June 17, 2005, 01:13:18 PM
man you're fast, jakob ... do you get tired of folks telling you how thankful they are all the time?
too bad.
 :wink:
thanks.
very much.
Title: Questions about Sifam meters
Post by: moonshot on June 20, 2005, 06:49:24 PM
Hello, After reading the various posts, I see that there are two different models of Sifam meters being used for the GSSL:
The AL19WF and the PPM 14.  

Are there any advantages to either?

Does the PPM 14 have better ballistics since it's a peak meter?  Which is cheaper?  I haven't been able to locate a dealer in north america who has either one of these.   Any suggestions?

thanks---Ron
Title: SSL HELP THREAD!!!
Post by: gyraf on June 21, 2005, 01:45:31 AM
Ron,

As mentioned several times, you need a standard, linear-scale meter, 1mA FSD sensitivity. The actual type has little or no significance. I think the original used a sifam presentor 19wf. in us, try meterdistributor.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dufo on June 22, 2005, 11:16:08 PM
I have a problem where the threshold is not working, it has no effect at all...

I measure correct voltages on the wiper legs, and my rails are ok and stable..., also...any kind of input hammers the meter to full scale and it only moves slightly with the input from there. Any ideas ?
Title: SSL HELP THREAD!!!
Post by: gyraf on June 23, 2005, 01:34:52 AM
look at the schematic. see the threshold circuit? quite simple really. check components and connections as always.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dufo on June 23, 2005, 01:38:11 AM
Thanf Jacob, doing that now..

Though I should have added, it WAS working fine for a long time, then all of a sudden....
Title: SSL HELP THREAD!!!
Post by: gyraf on June 23, 2005, 01:42:41 AM
could be controlboard-to-mainboard connection. check that voltage on pot viper reflects on TL072 output voltage (pin no's in schematic are switched between the two halves)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dufo on June 23, 2005, 02:12:58 AM
Jacob,

Im not sure how to count which pins are which on a IC. Heres how I explain what I found:

Top and bottom viperrs on threshold pot stable at 11.8V

MIddle viper swinging from -11.73V to +11.8V, seems ok there, yet threshold has no effect.

Then I turned the PCB over, now im looking at TL072, from the perspective of the bigger PS caps being closest to me. on the TL072 I have:

pin bottom right 11.8V (dosent vary with threshold)

next pin up -1.17V

next pin up 0.00V

top pin 0.00

moving to left hand side of TL072...

bottom pin from -2.95V to +2.95V verying with threshold

next pin up 0.00V

next pin up 0.00V

top pin up -11.73 V not varying with threeshold


Sorry for the unknowledgable crap description, just learning :0) thanks again
Title: SSL HELP THREAD!!!
Post by: gyraf on June 23, 2005, 02:17:12 AM
Figures looks right - but the pin with varying voltage vs. threshold turn should also carry a DC voltage following input level.

look up the TL072 data sheet for information and an example of opamp pinout. This is important stuff to know!!!!

check circuit around sidechain VCA and between TL072 and sc vca.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: dufo on June 23, 2005, 02:32:13 AM
Ok im looking at the datasheet and have the pins sorted out. the pin I mentioned with varying DC on threshold seems to be the output, pin 1.

It does indeed vary with input level too. up to about 3.5V DC at max input, the fgures I quoted in my other post are at 0db input....

going to check sidechain now.
Title: SSL HELP THREAD!!!
Post by: dufo on June 23, 2005, 02:44:10 AM
ok, I found a short near the VCA, right where on of the poly caps. I forgot that last time I used it (a while ago) I had to replace this cap ,long unecessary story.

Anyway fixed short, solved problem. Sorry to put you through that Jacob, but thanks anyway, much appreciated.  :grin:  :guinness:  :guinness:
Title: SSL HELP THREAD!!!
Post by: gyraf on June 23, 2005, 03:39:02 AM
good...  :thumb:
Title: SSL HELP THREAD!!!
Post by: dufo on June 23, 2005, 04:39:17 AM
One other thing, not a problem in terms of operation, but annoying...

As you increase compression right up with increasing threshold...

As soon as you come back the other way, my meter drops slowly but consistantly back down to zero. While its dropping threshold has no effect. Got to wait for it to get back to zero, or switch bypass out and then back in.

I think I remember reading this can be due to voltage reg's latching up? Is this right? Couldnt find anything in the meta...

thanks again.
Title: SSL HELP THREAD!!!
Post by: gyraf on June 23, 2005, 07:16:47 AM
Quote
can be due to voltage reg's latching up? Is this right?


no. TS7815 regulator latching up occurs at power-up only.. and only half the time, depending on what halfwave comes first when you switch on..
Title: SSL HELP THREAD!!!
Post by: drpat on June 26, 2005, 07:30:40 PM
...
Title: SSL HELP THREAD!!!
Post by: gyraf on June 27, 2005, 02:59:48 AM
Very often you need a bit of load for the 78/79xx regulators to act. Try putting in the 5532's and 5534's for load - they will survive up to +/-22.5V. If still -20V, change 7915.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: drpat on June 27, 2005, 01:54:40 PM
...
Title: SSL HELP THREAD!!!
Post by: drpat on June 29, 2005, 07:44:32 AM
...
Title: SSL HELP THREAD!!!
Post by: drpat on June 29, 2005, 08:02:34 AM
...
Title: SSL HELP THREAD!!!
Post by: drpat on June 29, 2005, 04:41:08 PM
...
Title: SSL HELP THREAD!!!
Post by: gyraf on June 30, 2005, 04:11:29 AM
No idea, sorry. As always, check for shorts and broken connections (cables, soldering)
Title: SSL HELP THREAD!!!
Post by: drpat on July 01, 2005, 02:54:29 PM
...
Title: SSL HELP THREAD!!!
Post by: tree on July 01, 2005, 05:16:14 PM
Sorry- have not seen this asked yet...so i kind of fear it might be a dumb question, but....
In the original schematic (Thanks Jakob!)and on the GSSL board itself (Thanks Gustav!) i see 2
larger caps in PSU section as 1000/35 value.
On the parts list i used (Thanks, Greg!) i don't see these listed,
the closest i have are values 1000u/63v.
Are these the 2 i am to use in this position?
Something to do with 115 vrs 220 perhaps?

a Canadian Question
  :green:
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on July 01, 2005, 05:24:13 PM
you can always use 1000u/63 instead of 1000u/35. /35 is the minimum rating for this cap. but make sure they fit to the pcb (pin spacing etc)
Title: SSL HELP THREAD!!!
Post by: tree on July 01, 2005, 06:37:12 PM
Thanks Silent..
Looks to fit perfect.
 :thumb:
Title: SSL HELP THREAD!!!
Post by: bpatural on July 03, 2005, 05:14:22 PM
Hello, I'm new here and just constructed the ssl compressor.  It works and sound beautiful, but my one question is: how do I calibrate the output on it?  It seems to be about 3db hotter than the signal going in.  It would be great if in bypass it was the same as the input level.
Thanks.
-brian
Title: SSL HELP THREAD!!!
Post by: gyraf on July 04, 2005, 02:57:17 AM
Hi Brian,

Welcome to "The Lab"..!

Look through the ssl-clone meta (you can use the link .:Meta-Meta:. at the top of every page here to get there) - we've discussed this several times. It has to do with running the unit balanced or unbalanced - and involves changing some 15K resistors to 27K.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Lowfreq on July 04, 2005, 10:25:58 PM
Hi everyone

I'm back with another simple power transformer question. (thanks Jakob for helping out with the last one)  :grin:

I went with a toroid for the gssl (jaycar MT2086 15+15 20VA), and i have had a quick look at some of the other threads on this, but i wasn't too sure of what the conclusion of those threads were.

So far: 2 x orange wires - go to iec inlet (cool got that)

Purple:                            to go to pcb
White and Yellow:             wired together to pcb(centre)
Red:                                to go to pcb

is this right? or should it be?

Purple:                            to go to pcb
Red and white:                 wired together to pcb(centre)
Yellow:                            to go to pcb

I'm sorry if there was a simple answer that i missed somewhere, and if someone could point me in the right direction, that would be great.

Cheers

Steve
Title: SSL HELP THREAD!!!
Post by: Lowfreq on July 04, 2005, 10:42:08 PM
Oops sorry everyone,

I think i've just figured it out. I found that .gif file about the tranformers, and that explained everything.  :oops:

I had wired to the two 0v wires together, which is wrong, but i'll go and sort that out now.

dont mind me.........., but thanks anyway  :thumb:

Steve
Title: SSL HELP THREAD!!!
Post by: mnats on July 05, 2005, 06:32:23 AM
After posting my own answer about wiring the transformer I found this (http://www.diyfactory.com/data/transformer_connections.gif) perfect explanation from Mark Burnley hosted at Kev's DIY Factory. Number 3 shows the correct wiring of secondary windings for the SSL.

The same information is also referenced in the meta, proving that even when you're answering a question you should do a search first :oops:
Title: Have a heart; help a dummy. Seriously. I am retarded.
Post by: ReggieReddog on July 06, 2005, 10:42:59 PM
Hey guys,
Been lurking around here for a while and was enticed into starting on the GSSL project even though I don't know jack about electronics and can barely solder.  I have absorbed as much from this site the the Gyraf site as I can handle, but some things go over my head.  I managed to get the PCBs stuffed for the most part, but I am hung up about a few things.  I think they have been explained before, but I am too dense to comprehend; so dumb it down for me. :oops:
   Here is the data on the toroidal transformer I have:  Amveco62063http://rocky.digikey.com/WebLib/Amveco-Talema/Web%20Data/62000%20Series%20Low%20Profile%20Miniature%20Transformers.pdf Wiring for USA voltage.    Now I think I solder the yellow and the red together or maybe solder them to the PCB in like the middle 2 holes on the right side of the transfmr section.  Then maybe I connect the....OK I have no clue.  Everyone seems to do it differently and there are two possible sections to connect to in the first place.  :sad:  I'm also bound to hook up the IEC plug-in wrong, so I would appreciate some guidance there as well.   And where the board is silkscreened +15V above -15V, are just normal jumpers supposed to go there or is that just a test point or what?
   
On a related note:  how does the on/off switch hook in there?  Does an extra wire off the transformer go to it or does it hook to the plug-in somehow?  
   
And on the subject of switches, which way do the darn things go in there?  The ratio and the attack switchers seem to go in right side up (turning the knob to 1, 2, 3, etc is about where it should be), but the PCB holes for the RELEASE switch are flipped around and I'm not sure which way to mount the switch.  There are only two choices I guess, but it would be nice to know the right one without soldering it all up wrong first.

One last minor thing before I quit bugging, I can't squeeze in the 5-pin terminals that go the XLRs without unsoldering some stuff.  Should I just forget them and solder direct to the board, or will that be a regrettable decision?  

Soooo sorry, but I would really like to make this work despite my own stoopididy.  Appreciate any help, and thanks for all the info that has been provided already.  If it helps, I used this parts list: http://members.cox.net/capstanrecording/SSLCloneParts.pdf (thx greg)  Dang already
                               Don't flame?
Title: SSL HELP THREAD!!!
Post by: cannikin on July 06, 2005, 11:51:02 PM
Don't solder the Red and yellow wires to the PCB!!

There a couple of things to think about first:

How to connect the IEC socket to a FUSE & On/Off switch then your Amveco Power transformer?

Primary: (the ones with Yellow Tubing around them)
Twist & solder the Yellow and RED wires together.
Twist & Solder the Black and Purple wires together.

Secondary:
Twist and Solder RED and Brown together.
Green
Blue

That will start you off.. I have to go to sleep now..
PM me if you have more questions.
Title: Re: Have a heart; help a dummy. Seriously. I am retarded
Post by: drpat on July 08, 2005, 01:54:24 AM
...
Title: Re: Have a heart; help a dummy. Seriously. I am retarded
Post by: dukasound on July 08, 2005, 11:34:43 AM
Hi Jakob and others
Before I make front panel for my GSSL tell me what value is for Threshold: -20db to +20db or -15db to +15db (like on original)
and value for Make-up: 0db to 20db or -5db to +15db (like on original).
Thanks
Duka
Title: Re: Have a heart; help a dummy. Seriously. I am retarded
Post by: ReggieReddog on July 08, 2005, 01:56:57 PM
Quote from: "drpat"
Quote from: "ReggieReddog"
   
And on the subject of switches, which way do the darn things go in there?  

                               Don't flame?



I think this has already been covered, but you can mount the switches either way.



K thanks.  I was afraid the switch would work backwards from what my panel will say if I don't get the 2 pins in the correct 2 holes.   I'm still stuck on the power switch.  Because I am too dumb for this.
Title: Re: Have a heart; help a dummy. Seriously. I am retarded
Post by: radiance on July 08, 2005, 02:52:56 PM
Quote from: "ReggieReddog"
Quote from: "drpat"
Quote from: "ReggieReddog"
   
And on the subject of switches, which way do the darn things go in there?  

                               Don't flame?



I think this has already been covered, but you can mount the switches either way.



K thanks.  I was afraid the switch would work backwards from what my panel will say if I don't get the 2 pins in the correct 2 holes.   I'm still stuck on the power switch.  Because I am too dumb for this.


It's always best to first make "whatever you're building" work, and THEN design the frontpanel.
Title: Re: Have a heart; help a dummy. Seriously. I am retarded
Post by: drpat on July 08, 2005, 04:24:01 PM
...
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on July 08, 2005, 07:20:26 PM
I haven't had the front panel cut yet, but I'm just saying it will be goofy if I have to design the front panel backwards because of my poor understanding of switch mechanics.  


And yes, I'm afraid the switches have D shafts, which I would prefer except that it looks like at least one of them will have to be pointing a little goofy.  
I guess I could just design the release settings sideways on the panel......and in backwards order unless I guess the correct way to put it in there......or something.    Or maybe I should just leave my front panel blank so it doesn't look like a mistake, and I'll just memorize what does what.  

Have I apologized for being a nuisance to this wonderful community yet?  
Apologies,

Reggie

PS:   :idea: Hey, let's say that I'm a female, like that other reggie on this board.  Does that get me more help?
Title: SSL HELP THREAD!!!
Post by: drpat on July 08, 2005, 08:34:32 PM
...
Title: SSL HELP THREAD!!!
Post by: dirk666 on July 08, 2005, 10:42:03 PM
How many VA is a good idea for this compressors transformer? Or is the straight amp rating more relevant?

I put a PCB mount 2x 0-18V   .138A  with 2.5VA in my first unit. (it runs a little hot, 15V would have been smarter)

But for my next one i'd like to use a toriod and they all seem to come with a much higher rating. 15VA being the smallest.
So is there a formulla for working out what the min requirement is?
That way I would actually learn something. Ace.



(also the 18V sticks up to high, gonna hafta make a bonnet scoop in the case
 :thumb: )
Title: SSL HELP THREAD!!!
Post by: dukasound on July 09, 2005, 05:04:28 AM
Hi
I saw on schematic one note about changing 15K if we use GSSL unbalanced.
In case if I would use in stereo insert, must I change 15K to 27K?
Thanks
Duka
Title: SSL HELP THREAD!!!
Post by: Greg on July 09, 2005, 12:29:57 PM
hi Reggie:

I got your PM and I will try and help you out.

Wiring the IEC and toriod:
It's kind of pointless to wire in a power switch if you don't have the front panel. So let's just leave this out for now until get power to the main PCB. First do what cannikin said about wiring the toroid. Now, on the IEC. At the top (the one in middle) is the GND. That wires to your chassis. Then there are two more contacts. One has an N by it, so that's the neutral. The other is the hot (ie 115VAC). For the primary, I think red and yellow go to the hot and purple and black to the nuetral, but double check this on the data sheet. For the secondaries, red and brown is the center tap, and that goes the middle point on the PCB, the green and blue go to the two other points (doesn't matter which one goes where). This will give you the AC voltage you need for the PSU.

Here's what I do for the switches:
Put them in so the round part of the D-shaft is pointing towards the bottom part of the daughter PCB. I use knobs made to fit a round shaft, so as long as the round part is facing downward, I can orient the knob so the set screw with hit the round part of the knob.

For the 5-pin connectors, I just use a Dremel and grind off the edge of the plastic until it fits. As long as the pins aren't damaged, it'll work fine.

Regarding test points, when you first power up the GSSL, make sure none of the ICs are in. Then look at the data sheet and it will tell you which pins are the rails. You can test your +/-15VDC and +/-12VDC.
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on July 09, 2005, 11:29:04 PM
Thanks, you guys are priceless.  I think I'm with you pretty much.  
IEC:  check.
Toroid:  check.  (I assume you are refering to using the section at the top of board when you were talking about hooking the secondaries, rather than the original section for the on-board trans.  I never woulda guessed that the other 2 secondary wires could hook up either way :? )
Switches:  Check. (I think...)
5-pin:  Check.  Good idear. (Don't have a Dremel, but I just sawed the 16-pins in half with a hacksaw so I'll manage a way.)
Test points:   Uhhh, I'll do some research on what rails are; but at least I can say I knew to leave the IC's out whilst testing!

Now here's a dumb question for you:  Where is the actual PCB circuit grounded to the chassis?  I know there is the ground loop that connects some stuff on the board to ground, but I can't figure out where it actually is grounded.  I mean, the IEC is grounded to the chassis, and I think the XLR input jacks are grounded directly to the chassis; but I don't see how the board is grounded.  I would think it would be at the screws that connect it to the chassis, but apparently I'm supposed to use non-conductive washers to prevent this.  
Am I so clueless that I'm going to electrocutionate myself?  
I'm real close to "getting it."  I can almost feel it.

Edit:  I think I figured out how the on/off switch is wired, so:
Power switch:  Check
Title: SSL HELP THREAD!!!
Post by: drpat on July 10, 2005, 06:42:55 PM
...
Title: SSL HELP THREAD!!!
Post by: drpat on July 10, 2005, 06:50:22 PM
...
Title: SSL HELP THREAD!!!
Post by: dirk666 on July 12, 2005, 05:46:47 AM
hey!
Was just cleaning up some papars lying around and found a proper schematic for the Gssl. And built the damn thing with only the layout pdf? So were did this come from? The top of the print-out didntnt come through so its not a complete one.
Can someone point me in the right direction?

Just as well nothing went to wrong with my first build but would be nice to have the proper schm to work off in future.

Cheers
          Scott
Title: SSL HELP THREAD!!!
Post by: gyraf on July 12, 2005, 05:57:57 AM
I Don't understand your question, Scott?
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 12, 2005, 06:38:55 AM
Scott,

You have all you need in one place at Jakob's site, schematic, gerbers, PDFs, description, datasheets:

http://www.gyraf.dk/gy_pd/ssl/ssl_sch.gif
http://www.gyraf.dk/gy_pd/ssl/ssl.pdf
http://www.gyraf.dk/gy_pd/ssl/SSL.zip
http://www.gyraf.dk/gy_pd/ssl/ssl_complist.htm

Jakob done an extremely good job.
What else do you need? :?

chrissugar
Title: SSL HELP THREAD!!!
Post by: dirk666 on July 13, 2005, 05:03:35 AM
Yeah that was a bit of a ramble sorry. Long story short, for some reason I never relised there was a proper schematic for the gssl compressor and built it off of the layout diagram.   :oops:  No questions, no problems. As you were
Title: SSL HELP THREAD!!!
Post by: martthie_08 on July 13, 2005, 06:03:03 AM
hey can anyone help me on this, I would like to have a 6.3V Pilot Light instead of the power status led on my gssl and I am not quite sure on how to hook it up.

possibility #1:
get an extra transformer 230V prim / 6V sec

possibility #2:
no extra tranny, take one of the 15V secondaries of existing power trafo and wire a resistor in series with the lamp. The lamp I have around here says it will consume 180mA. Any suggestions?
How do I calculate the correct value for the resistor, is it R = (15V-6V)/0,18A - I have a feeling this is not the way to go, especially since I will be using one of the secondary windings more than the other... any help really appreciated!
Title: SSL HELP THREAD!!!
Post by: gyraf on July 13, 2005, 06:25:34 AM
Quote
is it R = (15V-6V)/0,18A


Yes. 50 Ohms calculated. You may want to run the lamp at under-voltage to prolong life - in that case make the resistor 68R or even 100R. make sure to properly calculate power dissipation and size the resistor for this!

And make sure that your power transformer has the needed 180mA to spare for the light..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: martthie_08 on July 13, 2005, 07:01:29 AM
Thanks Jakob! I will try a 56R / 5 watts, that should give around 5 volts to the lamp (power dissipation will be around 1.8 watts for that resistor, according to my calculations).
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on July 13, 2005, 06:38:41 PM
Quote from: "dirk666"
Yeah that was a bit of a ramble sorry. Long story short, for some reason I never relised there was a proper schematic for the gssl compressor and built it off of the layout diagram.   :oops:  No questions, no problems. As you were



Well I can't even read a schematic (or at least not very well), so at least you're ahead of me.  :green:  I'm building mine off the layout diagram mainly.   Waiting on THATs (ordered 2 weeks ago from Blacklion), chassis, and figuring out drilling on front and back.  Found a place in Kansas that sells a cheap 24mm chassis punch (SESCOM), but man they are hard to deal with.

Maybe someday as a way to contribute to the community, I will try to put together a GSSL For Dummies guide so even novices can build one.
Title: SSL HELP THREAD!!!
Post by: dirk666 on July 14, 2005, 06:50:47 AM
Yeah ReggieReddogman I had thoughts along those lines too! But part of me  also thinks you would learn alot less if there was a 'how to' guide as oposed to a 'why to'. Unless of course you see it as simply a way of getting a highly prized compressor for less dough. Nothing wrong with that of course.
Title: SSL HELP THREAD!!!
Post by: drumtan on July 15, 2005, 05:37:00 AM
Quote
Yeah ReggieReddogman I had thoughts along those lines too! But part of me also thinks you would learn alot less if there was a 'how to' guide as oposed to a 'why to'.


I agree. I'm a complete newbie in the world of diy too , but i really enjoy
learning step by step , sourcing all the parts, find out 'bout different caps
etc..
That's part of the challenge even though a lot of patience is needed.
I like how people build there Gssl's different from each other , that's where the vibe and inspiration is coming from.
Would be too easy to have a step by step instruction :razz:

drumtan
Title: VCA problem
Post by: JD on July 16, 2005, 07:00:36 AM
Guys,

Hi, hope you can help, and sorry if this has been covered elsewhere, I've had a look through the ssl help threads but not found any clues. Okay I'm making my second gssl - the first went fine and sounds great, but the second has a problem in the right VCA. Measuring the voltages on the pins of the 5534 (without the chip) I get ~-2.2V instead of -0.8V for both pins 2 and 6 - inv input and output respectively  when comparing against my known good unit.

I'm checking resistor values and looking for shorts, but I'm a newbie and am a bit stuck so far. Can anybody give any pointers as to where look for the cause of this problem (left VCA voltages seem fine).

Thanks in advance...
Title: SSL HELP THREAD!!!
Post by: gyraf on July 16, 2005, 07:06:21 AM
There's not much that can be said about that other than the usual: check for shorts, proper supply voltage, soldering, component values and component integrity..

Jakob E.
Title: problem VCA
Post by: JD on July 16, 2005, 08:27:45 AM
Thanks Jakob,

I'm thinking a dodgy component, maybe. I don't have a capacitor tester at the moment so I'll probably try swapping a few of those out.

Cheers
Title: SSL HELP THREAD!!!
Post by: matthias_edp on July 17, 2005, 06:30:39 PM
hi there!

I have a question about the TL074 TL072 and the 5532/34.

I have a LF347n instead of a TL074
for the TL072 I received a LF353n

and for the 5532/34 I received ap versions

are these the same chips I need but with a different partnumber? can I use these chips without worry. Or do I have to buy the correct ones?
Title: SSL HELP THREAD!!!
Post by: gyraf on July 18, 2005, 03:39:54 AM
the 5532/34's are correct - only different pakage material. For the 072/4's - the LF's may work, but I haven't tried them, so there's no guarantees..

Jakob E.
Title: Best use for a BBE Sonic Maximizer?
Post by: idylldon on July 18, 2005, 01:15:21 PM
Turn it into a GSSL compressor:

(http://home.mindspring.com/~idyll/GSSLtop.jpg)

(http://home.mindspring.com/~idyll/GSSLfront.jpg)

Thanks for all the work so many of you contributed to make this project possible.

Cheers,
--
Don
Title: SSL HELP THREAD!!!
Post by: matthias_edp on July 18, 2005, 01:58:01 PM
ok i powered up my ssl clone ands working. it is compressing the signal. all switches and pots are working.

only with a very loud hum.

i checked al components again if they placed in the good posistion. and also the values.

someone an idea where i can start looking to solve the problem?
Title: SSL HELP THREAD!!!
Post by: gyraf on July 19, 2005, 01:53:12 AM
Matthias,

You just go through the usual steps, mentioned many, many times in this thread already.

Start out by checking your +-12 and +-15V supply lines for correct voltage and absence of ripple - and for distribution to all opamps.

Make sure that you have grounds connected properly to chassis and in/outs.

Then check for shorts, bad connections, and proper components.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: matthias_edp on July 19, 2005, 09:36:28 AM
i think i found the problem(or maybe part of it) the +12 volt regulator is an 7815 instead of an 7812. rs-components gave me the wrong one. and i probly didn't checked or something.

is het possible that some components are broken now? because of the 3 volt difference?
Title: SSL HELP THREAD!!!
Post by: gyraf on July 19, 2005, 09:50:22 AM
No, it should be fine if you put in a 78L12. But check, check, and recheck all your other components!!!

Jakob E.
Title: SSL HELP THREAD!!!
Post by: matthias_edp on July 20, 2005, 09:01:16 AM
ok I've checked a few things. The voltages from de regulators are ok now I think.

But not the hum is the problem also the very low volume that the clone gives.  When I remove the vca from the sidechain. The volume is normal I think. I tried to replace the vca but that didn't help at all.

I have those dbx c1252 vca's(are there datasheets available somewhere, I can't find it on the internet. Only a japenase version). Maybe that is the problem? I also search for shorts or bad soldering but I think thats ok.

I also checked the values of the components. Thats allright too.

There's only one thing. When I powered up de SSL for the first time the 22u cap nest to the text on the pcb thats says "psu" exploded because of wrong polarity. I replaced it and also the 10r resistor next to it.
is it possible that I also have to replace the .1 cap between de 22u en 10r?
I think not because the voltages are allright. but maybe for the hum problem.
Title: SSL HELP THREAD!!!
Post by: gyraf on July 20, 2005, 09:07:30 AM
the 0.1 polyester cap won't need to be replaced.

Are you sure you're putting in the sidechain VCA the right way around? Note that it is mounted opposite of the audio channel VCA's! Most often, the VCA's won't survive being put in wrong.

How much gain do you have from input to output, compressor bypassed?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on July 21, 2005, 11:57:16 AM
:green:  :green:  :green:
I'm sure this is dumb and am sooo sorry to interupt.
The  pots (threshold and make up) i got from mouser have no terminal markings....been searching meta for wiring info on potentiometers for gsl. Also read related Rod Elliots pages (great)....

If i'm looking at the front (knob-side) of the pot, is it true that farthest left terminal is #3 (+input), middle #2(wiper) and farthest right #1(gnd).

Seems so counter intuitive.

thanks anyone?
 :oops:
Title: SSL HELP THREAD!!!
Post by: drpat on July 21, 2005, 12:55:57 PM
...
Title: SSL HELP THREAD!!!
Post by: tree on July 21, 2005, 12:59:08 PM
um...
just to clarify question;
If turning pot CW, leftmost terminal position = post 3 (input), middle = 2 (wiper) and rightmost = 1 (gnd)?

thanks
Title: SSL HELP THREAD!!!
Post by: tree on July 21, 2005, 04:24:52 PM
thanks. drpat...pictures worth a thousand words.
Title: SSL HELP THREAD!!!
Post by: tree on July 26, 2005, 04:15:23 PM
After much checking and rechecking my solder joints etc, finally got to power up SSL board to check power rail voltages: + 15 reads at about 14.8 and  :cry:  :cry: can't seem to locate  - 15 anywhere.
Transformer checks fine by itself.
The 2 big caps read at about +22 and -22. Is that about right? (using old small analog vmeter hard to get acurate readings)
Am wondering about 7915.  Maybe toasted?

My first build, a bit disappointing...thought i'd been so careful...

Can someone confirm the best places on the mainboard to meter -15... any other suggestions or advice would be really really apprecited.
thanks all.
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 26, 2005, 04:27:49 PM
Before powering up it is a good idea to leave out the VCAs in case something is wrong, at least you will kill only some cheap opamps that you can find anywhere.
If you look at the PCB from the component side, you can locate somewhere in the midle of the board (between the transformer footprint and two VCA rectangles) two bypass wires, one is labeled +15V and the other -15V. Measure voltages referenced to the GND (for example the mid pin of the five pin input connector)
If everything is OK you can put the VCAs into the sockets.

chrissugar
Title: SSL HELP THREAD!!!
Post by: mfdu on July 27, 2005, 01:16:56 AM
just got my boards from CHef @ audiokitchen.  very tidy.  i'll be getting into part stuffing this weekend.  
dont have the VCA's (THAT Corp haven't felt like returning my emails yet) but i also have to finish my fault finding on my pair of 1176's, so i'll be busy enough i think.

cheers.

chris.
Title: SSL HELP THREAD!!!
Post by: tree on July 27, 2005, 02:40:13 PM
Thanks Much Chris...

Yes, those are the points i used for referencing the DC and since my meter showed 0 on the - 15 side, i suspected and replaced reg. 7915.

NOW, with no socketted bits mounted on the card, the -15 rail  reads between -15.30 and -15.32.
On the +15 rail i get between +14.98 and +15.00.

How close to identical should these rails be???

Real glad just to see anything on the -15 side.
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 27, 2005, 05:36:39 PM
Those voltages are OK, you don't have to have exactly 15V.
OK so now you have the good voltages. next logical step is to put one by one the 5532 and 5534 opamps and measure the voltages at the coresponding pins. Add one chip at a time, measure, if OK add next chip, and so on and so on till you find the chip that kills the -15V.
If everything is OK you can add the VCAs and measure the voltages on their pins.
BE CAREFUL! Avoid to make shorts between pins while you measure because in some situations it can be fatal to some chips.

chrissugar
Title: SSL HELP THREAD!!!
Post by: tree on July 27, 2005, 06:09:14 PM
Great. Thanks Chris.
Was just about to plug everything and switch it on to "see" what happens :green:
but appreciate the need for patience to save little disasters.
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 27, 2005, 06:14:16 PM
That is the way to do it with the least amount of dammage. :grin:

chrissugar
Title: SSL HELP THREAD!!!
Post by: gyraf on July 28, 2005, 01:54:11 AM
(Good work here, Christian :thumb:  - Thanks!)
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 28, 2005, 02:25:36 AM
Thank you Jakob for the apreciation, but it is nothing compared to what you do for our comunity. You are the man. :thumb:

chrissugar
Title: SSL HELP THREAD!!!
Post by: tree on July 28, 2005, 04:45:45 PM
Sorry to keep bothering....for a minute there bet, you thought you'd seen the last of my particular greenness, but noooooooo

Been pouring over meta on this, haven't seen anything specifically like it....though there are some threads indicating tlo72 might have something to do with it???

Symptom;
Does not sound as if compressing.
Even with ratio set at 10:1 and threshhld almost full counter clockwise, unit does not SOund as if compressing.

-Meter works.
-Output gain works.
-Bypass works.
-Threshold seems to work - reads hotter on  meter when turning counter clockwise - though reduces apparent output volume more extremely than i would expect.

Does this sound like similar issue as meta thread,
http://www.groupdiy.com/index.php?topic=5324???

Very Very Thankful for All your help.
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 28, 2005, 06:06:00 PM
Quote from: "tree"

Even with ratio set at 10:1 and threshhld almost full counter clockwise, unit does not SOund as if compressing.

-Meter works.
-Output gain works.
-Bypass works.
-Threshold seems to work - reads hotter on  meter when turning counter clockwise - though reduces apparent output volume more extremely than i would expect.


If the threshold works, the meter show activity and the gain is reduced it is compressing. That is how compression works. You should compensate with makeup gain.

Although it is possible you have a ratio problem. If you use for example 2180 you should change the 100K resistor from pin8 of TL074 to pin2 of TL072 (ON SCHEMATIC!!!  There is a difference between the schematic and PCB, the pins of the two opamps in TL072 are swaped on the PCB) to 120K.
That will make the ratios to work correctly.

chrissugar
Title: SSL HELP THREAD!!!
Post by: tree on July 28, 2005, 11:27:56 PM
Hmmm.
Sorry, Christian, still doesn't sound like compression to my ear,... Threshold control seems to be acting more like a counter volume control, if you know what i mean - when set fully counter clockwise and with gain m.u. fully cranked clockwise (regardless of ratio, attck or release settings) almost no signal is present. Also, for instance it doesn't seem to pull UP  drum room ambience much at all compared to my other compressors (smart C1, tubetech laca2b, 1176, etc... i am also a little familiar with original ssl bus comp from mixing on e series desks).
[/quote]
"If you use for example 2180 you should change the 100K resistor from pin8 of TL074 to pin2 of TL072 (ON SCHEMATIC!!! There is a difference between the schematic and PCB, the pins of the two opamps in TL072 are swaped on the PCB) to 120K.
That will make the ratios to work correctly"


Sorry again, i'm very new at this - getting a bit dizzy....
I am using 2180LA s thruout Gustav's board.
If looking at pcb component side, - with 3 vcas accross the bottom- am i right that the 100k on TLO74 pin 8 you are talking about is located directly below TLO74 as the topmost of 4 resistors; 100k, 620k,100k and 220K??
And do you mean i should just take that 100k out and replace it with 120k??
(Its trace doesn't seem to go to pin 2 of TLO72 on Gustav's pcb or am i wrong)

Pin 2 of TLO72 on the pcb seems to go to 100p, 56k and 100R etc., no?

Hope you forgive the green ramble. I must repeat, i really appreciate your help. I'm hoping maybe the unit is compressing but at very low/light ratio or something that i can't quite recognize as compression?

 :?
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 29, 2005, 04:26:00 AM
Quote from: "tree"

If looking at pcb component side, - with 3 vcas accross the bottom- am i right that the 100k on TLO74 pin 8 you are talking about is located directly below TLO74 as the topmost of 4 resistors; 100k, 620k,100k and 220K??
And do you mean i should just take that 100k out and replace it with 120k??


Exactly. Change that 100K resistor to 120K (yes, the topmost from that group of four)
I especially specified that I mentioned ON SCHEMATIC because there is a little error between the schematic and PCB (opamp1 of TL072 on schematic is opamp 2 on PCB, and opamp2 on schematic is opamp1 on PCB).

Quote from: "tree"

Hope you forgive the green ramble. I must repeat, i really appreciate your help. I'm hoping maybe the unit is compressing but at very low/light ratio or something that i can't quite recognize as compression?


No problem, we are here to help each other.  :thumb:
It looks like you have a ratio problem so if you change that 100K to 120K it will work OK.
Do it, and report back to see if your problem is gone.

chrissugar
Title: SSL HELP THREAD!!!
Post by: chrissugar on July 29, 2005, 04:36:11 AM
Here is a thread dedicated to the ratio problem:
http://www.groupdiy.com/index.php?topic=944&start=0

A quote from that thread:
Quote from: "Steffen"

without the mod the 2:1 ratio was something like 3.5:1 and 10:1 was inverse!!! 10 dB input level boost was resulting in 0.5dB level drop on the output! (ratio = 10: -0.5   ???)


I have the feeling that you have that "inverse" problem. I had it with my first SSL comp and after the mod the ratios were correct. Read my posts in that thread, I made a comparison between the two kind of ratio corrections and had a verdict.
Title: SSL HELP THREAD!!!
Post by: drpat on July 29, 2005, 04:52:35 AM
...
Title: SSL HELP THREAD!!!
Post by: tree on July 29, 2005, 11:04:21 AM
Great. Thanks, Chris. Thanks drpat.
I'll report back after re examining threads and testing.
 :thumb:
Title: SSL HELP THREAD!!!
Post by: tree on August 01, 2005, 01:24:06 PM
after much thread reading again... changed the following...

-100k to 120k between 074 and  072
-the noted 15k to 27ks for unity gain mod
-put 47k in series onto positive leg of threshold (series = one leg of res to pot + post, other leg to + wire, correct?)

FINALLY got to do some testing today and am quite sure that although i can at least hear some compression artifacts going on now,  something is still WAY off somewhere. Try as i might, i cannot come close to getting the sound of say,the kik& snare to "pump"  in the slightest, if you know what i mean.
RATIO, ATTACK and RELEASE seem to act only very very subtley when A/B'd to identical  settings and program material thru my alan smart C1. I'm sure that the two should by no means be identical sounding but shouldn't the effect of pumping (16db @ 4:1 on kik and sn, for instance)be audible on GSSL? My GSSL currently seems to almost do nothing in this case except decrease volume via threshold.

The THRESHOLD is acting more like a volume control - when fully counter CW almost all signal is gone and can not be made up for by GAIN pot (even when GAIN cranked fully CW).

Have gone over and gone over the main board - cleaning and resoldering any iffy looking joints etc.
Is there some area i should zero in on as far as rechecking resistor values goes?

Feel like i have about 20db gain reduction on my brain that i'd really rather use on a kik and snare.

thanks for any help or direction you might have.
Title: SSL HELP THREAD!!!
Post by: drpat on August 01, 2005, 01:36:01 PM
...
Title: SSL HELP THREAD!!!
Post by: tree on August 01, 2005, 02:31:27 PM
thanks drpat.
do you mean front panel "control boards"?

Meant to mention also that the 120k (that i put in place of the 100k as suggested)
looked to be about 117k on my meter before i put it in....it was the only one i had. Make a dif?
Title: SSL HELP THREAD!!!
Post by: tree on August 06, 2005, 12:31:10 AM
Have gone over the control board many times redoing any suspicious looking soldering, checking rechecking wiring of knobs and all resistor values (by colour code)everything seems good there, but still no go.

Voltages seem good too, but the only things that seem to be truly doing what they should are volume and bypass. Threshold acting only as a kind of volume control that reduces gain  to almost null when cranked fully counter c.w.- even when gain make  up is cranked fully c.w.

So i guess it's time to start pulling stuff out of the main board and checking voltages? Or?

Considering these odd symptoms, does anyone have any suggestions as to where to start this process or how - bearing in mind my cursed green nature...???

Frustrated but willing. Thanks any and all.
 :?
Title: SSL HELP THREAD!!!
Post by: gyraf on August 06, 2005, 03:52:04 AM
Tree,

Try tracing the sidechain signal all way through to DC control voltage at the vca's..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on August 06, 2005, 11:27:55 AM
Hi Jakob;
i see. will do.

s.
Title: SSL HELP THREAD!!!
Post by: tree on August 07, 2005, 10:51:30 PM
:shock:  :shock:  :shock:  :shock:  :shock:  :shock:  :? etc etc. :oops:
i've beenreading, re reading and metering all weekend, trying to make some troubleshooting sense on my own, but i seem to simply be over my head with this first build...that so far doesn't work....
 
Quote
Tree,

Try tracing the sidechain signal all way through to DC control voltage at the vca's..

Jakob E.

Used 1k test tone @ 0db for unit DCVolt Meter testing...my first dumb question is; Is it possible to "trace a signal" thru this kind of project with only a v.meter?

At Jakob's suggestion and from previous threads it looks like i should first look seriously at TLO74, Pins 1, 7, 8 and 14 in particular?

Pin 1; DC varies with signal level (via thresh) .24-.65
Pin 7; DC barely varies with signal, .01 -.02
Pin 8; DC varies with signal level, .01 to -.52
Pin 14; DC varies with level input, -.48 to -4.9

Pin 14; DC also varies with ratio selection;
1:2 ; -.47
1:4 ; -.14
10:1; +.16

when unit is in bypass
Pin 1; 2.01
Pin 4; 12.46
pin 7; .04
Pin 8; .01
Pin 14; -.45

I can't help think these are mostly awful low as readings?
I measured all kinds of other suggested DC points today, :shock: but since i don't know where i'm at already, thought i best start right at TLO 74 and ask for advice...with the usual apologies.
so...
What kind of trouble am i in so far???!!!!

thanks all.
Title: SSL HELP THREAD!!!
Post by: tree on August 18, 2005, 12:15:15 PM
GOT IT!!!!!!!!!!

I idioticaly managed to put a 47k resistor where 47R belonged!!!!!!
In VCA section.
Didn't even catch it until my SECOND time thru checking ALL values AND after a SECOND time thru resoldering ANYTHING looking remotely suspicious.

The box sounds great, btw and
I've learned a ton along the way.

Thanks Chris, Drpat and of course, Jakob!
Your patience and help truly appreciated.

"CHECK AND RECHECK", indeed.
  :green:
Title: SSL HELP THREAD!!!
Post by: chrissugar on August 18, 2005, 04:48:20 PM
Hey Tree,

Glad your SSL is finally working.

There is one advice I can give to all DIYers and mostly to beginers. Although I build electronic circuits since I was 5 years old, I still do the PCB stuffing with great care. I don't trust my capability to decode colour code from resistors and also don't trust the colours from the resistors (I know, I'm paranoid), so I measure each resistor before I put it in it's place.
Look at the schem, look at the PCB, take the resistor, measure the resistor, put it in it's place and then check, and then check again. I know it is slow and seems crazy, but for me this method works and never had to troubleshoot one of my projects in the last few years.
I have to repair many things for others, and I hate to repair, so I try to do my best to not be in the position to repair my own projects.
Trust me, this method is much more rewarding even if you do it much slower and you are concentrated, than building the thing quickly and then to waste more time for troubleshooting.

chrissugar
Title: SSL HELP THREAD!!!
Post by: Flundran on August 19, 2005, 01:34:17 AM
I'm currently troubleshooting my control PCB, measuring up values.

I'm having some difficulties measureing on some resistors allready soldered to the PCB. The voltmeter show an incorrect value. When I desolder the resistor from PCB and measure it, Voliá! The value is correct. What is the reason for this phenomena?
Title: SSL HELP THREAD!!!
Post by: martthie_08 on August 19, 2005, 04:02:39 AM
you only have to desolder one end of the resistor in question.

in general: when you measure resistance with an ohmmeter from point A to point B in a circuit, you are always measuring "the path of least resistance", when you are measuring a resistor for example and there is another resistor with the same value hooked up in parallel, you will get half the resistance reading of one resistor... not very scientific, but I think you get the idea?
Title: SSL HELP THREAD!!!
Post by: Flundran on August 19, 2005, 04:33:43 AM
Ahh, ok, that cleared it up. Thanx martthie_08  :wink:
Title: SSL HELP THREAD!!!
Post by: drpat on August 19, 2005, 04:40:29 AM
...
Title: SSL HELP THREAD!!!
Post by: Flundran on August 20, 2005, 02:52:58 AM
Ok, I would need some help troubleshooting my first DIY compressor..

It's passing signal thru fine, both channels. Makeup pot work. But no compresson is going on and the meter is frozen in a postition slightly above zero.

Today I made a discovery: When I adjust signal level (on input) to a certain level I suddenly get a VERY gentle compression on the sound, and the meter is bouncing VERY gentle... The frame for the input signal is about 1-2 dB. When the input is above or under, the old symphtoms comes back.

This is an checklist based on something Jakob wrote on page four of this thread:

1.) Check that you have the needed +/-12V voltages present.

2.) Check that you have signal coming to your sidechain, TL074 pin7.

3.) Check that you have DC varying with signal at the output of the sidechain, TL074 pin8

4.) Check that pin 1 and 7 on the TL074 has DC varying with signal level as well as a superimposed DC signal from threshold (TL072 pin1) and makeup (TL072 pin7). These two are your VCA control voltages.

I've checked all above in my SSL, and it all seems correct. Any suggestions on what to do next?
I'm using two DBX 202XT's in this SSL b.t.w.

/Flundran
Title: GSSL not compressing
Post by: higginsrob on August 22, 2005, 10:30:31 PM
Can someone please help me :cry: I've finished stuffing my GSSL, now it lights up and passes audio, but no compression or metering (meter jumps at power on, then back to 0).  The knobs don't do anything.  I've checked the wiring, I have +/- 15V, and TL074 seems to be functioning ok, but where do i check next?

If anyone is in the LA area, I could buy you a few :sam:'s to take a look at it.  I'm new to this so it's probably an easy fix

Thank you

Rob
Title: SSL HELP THREAD!!!
Post by: mfdu on August 22, 2005, 10:38:52 PM
tree

thanks for your summation of points to check on the ssl - good timing.

i am only getting a very low level distorted signal out of my ssl.

have tried swapping vca's around to no avail.  have not yet tracked voltages, but the +12/-12 is hitting the board fine.

in place of the 6.8uF cap of the control board, i used a 6.8uF BP electrolytic.  is the fact that it is not a directional cap causing a problem?

(i used the same on my 1176's and suspect thats the problem there too)

read through the entire thread, but no mention of the fault i am experiencing.

any tips?

chris.
Title: SSL HELP THREAD!!!
Post by: gyraf on August 23, 2005, 04:50:47 AM
chris,

There's only one way to do this: check for shorts, connections, and component values. Use a printout of the PCB layout for reference - and an ohmmeter (in continuity mode) to check for unwanted shorts.

Check that you have correct supply voltage on all appropiate IC supply pins.

Also try to isolate your problem to input- or output stage - you have the output of the input stage at one end of the two 47K resistors summing into the sidechain.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mfdu on August 23, 2005, 05:46:26 AM
its the whole pelasure and pain thing, isn't it?

i do really love diy, but . . . no.  thats it.  i really do love it.

if i can get the weekend off the wife, i'll be up to my elbows in ssl bliss.

sionara.

chris.
Title: SSL HELP THREAD!!!
Post by: drpat on August 23, 2005, 06:32:20 AM
Sounds like a weekend ON the wife would be much more fun anyways!
Title: SSL HELP THREAD!!!
Post by: mfdu on August 23, 2005, 06:01:08 PM
cheeky
Title: SSL HELP THREAD!!!
Post by: dirk666 on August 24, 2005, 01:28:14 AM
An odd fault.

the threshold pot, turned clockwise , fades the power led down?

ive had this unit working before and took it apart to fix the inter PCB connections(wiich were intermitant)

got no sound now either

Just thought id see were to start looking. Any ideas?
Title: SSL HELP THREAD!!!
Post by: gyraf on August 24, 2005, 03:52:37 AM
Quote
the threshold pot, turned clockwise , fades the power led down?


We've had that before - search the archives..

I don't remember the exact problem, but my guess is something shorting to the centre pin of the pot either on the control pcb, at the inter-pcb connection, or at the mainboard. Try tracing pot-centre-pin all way through and check for shorts to nearby things, gnd, and psu lines

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on August 25, 2005, 06:15:12 AM
My SSL is passing signal thru fine, but I can't get any compression. It seems there's something is wrong with threshold signal.

I have a question reg. CV to SC. Shouldn't this vari with threshold level? I've done measurements at TL072 pin 7, and the voltage here varies with audio signal, but is the same regardless of the threshold position.

/F
Title: SSL HELP THREAD!!!
Post by: gyraf on August 25, 2005, 06:34:43 AM
..the two halves of the TL072 is switched on the schematic, pin numbers differ..
Title: SSL HELP THREAD!!!
Post by: Flundran on August 25, 2005, 08:05:02 AM
Ok. At TL072 pin1, I get with threshold set all the way CW: 0.01V, and CCW: -0.01V.

I just discovered the fault when measuring resistances...

The two 47R in the SC section are in fact two 47K on my PCB!! I will run to ELFA tomorrow and buy the right components... Hopefully this will fix it.

/F
Title: SSL HELP THREAD!!!
Post by: Flundran on August 26, 2005, 05:15:08 AM
Ok, now I have compression, and the threshold seems to work. But the compression (and gain reduction) is very gently, even with ratio at 10:1 and threshold at full anti-clockwise.

From TL072 pin1 I've measured the following voltages:

Threshold at CCW: -2.99V
Threshold at CW: +2.99V

Are these values correct?


/F
Title: SSL HELP THREAD!!!
Post by: gyraf on August 26, 2005, 06:11:59 AM
check for shorts, components and breaks, then check again. If you read back through this thread, you'll find that the problems comes in these categories.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on August 26, 2005, 08:05:39 AM
Thanks Jakob.


If there is a 'correct' value of tl072 threshold output (pin1) I would be greatful if anyone could help me with this.

/F
Title: SSL HELP THREAD!!!
Post by: gyraf on August 26, 2005, 08:16:27 AM
I don't have a unit to check against.

Use logic: you feed the IC +/-12V (from the threshold pot) into the inverting input through a 220K resistor. You have 56K feedback resistor. The gain should be 56/220=0.25x - giving you some +/-2-3V at opamp output when the unit is in bypass. If it's not bypassed, there will probably be a lot of interaction due to feedback through the control circuit.

Check that you have -12 to +12V at one end of the 220K resistor when varying threshold. Check that you have approx. 0V at the other end of said resistor (as it's a virtual-ground coupling).

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Flundran on August 26, 2005, 10:30:30 AM
Quote
Check that you have -12 to +12V at one end of the 220K resistor when varying threshold. Check that you have approx. 0V at the other end of said resistor (as it's a virtual-ground coupling).


Checked. Seems right.


I also have a pretty disturbing humming on both channels. It's increasing with makeup pot. Maybe a short-out somewhere?
Title: SSL HELP THREAD!!!
Post by: gyraf on August 26, 2005, 12:32:47 PM
..check all four powersupply lines for correct voltage and noise..
Title: SSL HELP THREAD!!!
Post by: Flundran on August 26, 2005, 12:54:33 PM
All four is rails ok...


When I accidently grounded the -12V rail (next to the threshold pot), the humming stopped...
Title: SSL HELP THREAD!!!
Post by: quadwould on August 30, 2005, 06:02:36 PM
So after having read the whole thread twice...  (my eyes hurt now)  i am wondering abou tthe voltages i observed.

All voltages measured without IC installed.   all voltages above Millivolts are listed.  i didnt write the mV measurements.  all grounds/earths do seem ok though.

(http://i14.photobucket.com/albums/a335/quadwould/GSSLvoltages.jpg)


i do wonder why the voltages for pin 6 on the SC VCA was 3.3v and falling   and why Pin 6 of TL074 was 3.9 and falling
Title: SSL HELP THREAD!!!
Post by: discobloud on August 30, 2005, 09:36:10 PM
hey all.  i wish there was a forum for newbie's to forums and spelling for that matter.  so yes total newbie.  of course questions about the SSL.  

Which wires from the transformer go where?  does it matter blue/red.  I'm looking at other peoples photo's and posts and figured where the leads going to the pcb connection are.  i have a multimeter and will use it if forced.  i'm in north america if that helps.  which autobot can transform?

some photo's ground pin 1 on xlr in.  must i ground?  what about the output?

next question anyone have: part numbers for mounting hardware and  xlr screws, hole sizes for standard neutrik fare, tips and tricks?

much appreciated.  

disco
Title: SSL HELP THREAD!!!
Post by: quadwould on August 31, 2005, 01:52:51 AM
welcome disco


hardware mounting and for xlr jacks  i use #4-40  (that is a width and threading standard) a various lengths and typs.  Slotted head usually, but i get brass, black and silver ones  these can be obtaiend at local hardware stores, Home Depot or through some catalog parts companies like Digikey, Mouser, and Newark


which transformer do you have??  part number

the hole size for the typical neutric XLRs is 15/16 inch   the greenlee hole punch of that size is rather nifty

are you in Canada or the US?
Title: SSL HELP THREAD!!!
Post by: gyraf on August 31, 2005, 04:12:53 AM
Quad,

Quote
All voltages measured without IC installed.

This is only good for initial check, tells us only little about circuit intergety

Quote
i do wonder why the voltages for pin 6 on the SC VCA was 3.3v and falling and why Pin 6 of TL074 was 3.9 and falling


Pin6 on the SC vca is grounded, surely you mean pin8 -
22u Capacitor discharging. Look at the schematic.


Disco,

As quad implies, transformer colour coding depends entirely on what exact make and model transformer we're talking about. There is no standard notation for this, you need to know your transformer AND your circuit. Search the archives for examples of how to find the odds and ends on power transformers - it's been described several times.

And btw: If you post your location in your profile, it is often much easier to help, as many questions are area-specific..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: discobloud on August 31, 2005, 10:30:43 AM
thanks guys.  i'm in canada, montreal to be exact.  ok i think i'm getting this whole internet/messageboard/diy/research thing after reading till my eyes bled.  i'll check the data/spec sheet for the info on the primary...  i'll check the home depot today.  thanks again guys, i'll let you know when i test this bad boy out.  letters to tape-op.

disco
Title: SSL HELP THREAD!!!
Post by: quadwould on August 31, 2005, 03:59:14 PM
Jakob.  as usual you are right.

Yes, it is pin 8 of the SCVCA and pin 6 and pin 7 of the TL074.  so is this ok that the vltage is discharging?

also I was testing without ICs in becasue i dont want to fry any.  so if its all good I will put them in and retest.
Title: SSL HELP THREAD!!!
Post by: gyraf on September 01, 2005, 02:39:38 AM
..all looks good, I think..
Title: SSL HELP THREAD!!!
Post by: quadwould on September 01, 2005, 10:03:36 PM
IT works!!!  .......... Sorta



without the control board it sounds great. granted its just like bypass....

there is No hum at all though...  and thats without grounding anything.. just the pcbs, xlrs and xformer meter and pots on my bench.   So thats a happy thing.

With the control pcb attached..... hings get FUN.,


the meter is SLAMMED/ Pinned all the way up with the slightest amount of programme material.


for this unit i am using a Be*****er meter.  i didnt put the 2K nor the 330.  
 around the meter.  but then i experimented with the 2K in aand the 330 in and other combinations.   Still nothing  Pinned meter.

makeup gain works well....


when control PCB is attached.  and on (not bypass mode)  everything is really really compressed like and 1176 in NUKE... but this is at all ratios, and the threshold seems to not work, har dto tell as the levels are SOOOOO LOW  the release and attack seem fine though.

i will keep poking around, but wonder if i will find the problems...

 :?
Title: SSL HELP THREAD!!!
Post by: desol on September 06, 2005, 11:00:51 PM
What tests should i do before i power up my ssl. Everything's in but the VCA'S...i've tested for 15 vdc and 12 vdc..they look good...anything else i should look at before installing the VCA's?

Thanks :)
Title: SSL HELP THREAD!!!
Post by: discobloud on September 07, 2005, 12:53:25 AM
hello.  more newness.  first off, i turned this thing on and no smoke or white bubbles(yes for me and for you for making this thing available to regular dudes with hair) that burst.  secondly, i want to use a DPDT(the big metal ones that say: "ON/OFF") type switch instead of the rotary type.  how the heck do you wire this thing.  if you wire it wrong will it do strange things?  so far all i got is strange things, some no brainer wiring love is needed.

disco
Title: SSL HELP THREAD!!!
Post by: discobloud on September 07, 2005, 12:53:35 AM
hello.  more newness.  first off, i turned this thing on and no smoke or white bubbles(yes for me and for you for making this thing available to regular dudes with hair) that burst.  secondly, i want to use a DPDT(the big metal ones that say: "ON/OFF") type switch instead of the rotary type.  how the heck do you wire this thing.  if you wire it wrong will it do strange things?  so far all i got is strange things, some no brainer wiring love is needed.

disco
Title: SSL HELP THREAD!!!
Post by: discobloud on September 07, 2005, 12:53:46 AM
hello.  more newness.  first off, i turned this thing on and no smoke or white bubbles(yes for me and for you for making this thing available to regular dudes with hair) that burst.  secondly, i want to use a DPDT(the big metal ones that say: "ON/OFF") type switch instead of the rotary type.  how the heck do you wire this thing.  if you wire it wrong will it do strange things?  so far all i got is strange things, some no brainer wiring love is needed.

disco
Title: SSL HELP THREAD!!!
Post by: discobloud on September 07, 2005, 12:53:59 AM
hello.  more newness.  first off, i turned this thing on and no smoke or white bubbles(yes for me and for you for making this thing available to regular dudes with hair) that burst.  secondly, i want to use a DPDT(the big metal ones that say: "ON/OFF") type switch instead of the rotary type.  how the heck do you wire this thing.  if you wire it wrong will it do strange things?  so far all i got is strange things, some no brainer wiring love is needed.

disco
Title: SSL HELP THREAD!!!
Post by: discobloud on September 07, 2005, 12:54:48 AM
sh*t just posted four times.  newbie's rule.
Title: SSL HELP THREAD!!!
Post by: mfdu on September 07, 2005, 01:54:09 AM
those switches are pretty easy, because they simply are on, or off.
is the switch a dual row of three prongs?  
the middle of each row simply conects to the outer prongs when switched on.  cant go wrong.

but i have.

units not passing audio.  chased all +/- 12 and 15 - all there.  yet to chase 1kHz through the circuit.

got a couple of points where there is -0.85Vdc on the VCA 5534's , 13.67Vdc and 1.64Vdc on the output 5532's and -0.61Vdc on a pin each of the input 534's
tl074 shows 0.22, -0.15, 0, 0,0, 0,  -12.15, 12.10, 0.1, 0, 0.02 , 0, 0, 0
(phew is that all?)

all voltages match each side, the 12V is stable as.  but no signal passes.

tried disconecting the control board but no change.

have not tried changed 5532/5534's because they are showing the same volts and stable.

i know next step is chase the signal to where it stops, but any one (gyraf?) got a tip?

chris.
Title: SSL HELP THREAD!!!
Post by: gyraf on September 08, 2005, 04:25:12 AM
Chris,

Not passing audio at all is a rare symptom.

Make sure that opamps ('32 and '34) are correct types. Make sure that you mounted in and out to the appropiate connectors  :razz:

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on September 09, 2005, 12:40:25 AM
Hey Jakob...
Should i be able to check continuity between the "common" post and "selected position" posts of the lorlin attack switch, when it is installed in the circuit?
My tester shows some continuity between the "common" post and some of the "non selected" post positons as well as the selected position.
Normal?
Title: SSL HELP THREAD!!!
Post by: gyraf on September 09, 2005, 04:29:57 AM
Normal, methinks, when measured in-circuit.

Consult schematic for explanation, or unmount switches to check them. They rarely fail - unless "programmed" wrong (i.e. switch position is "behind" the endstop when this is put in). Always make sure to turn the switches fully ccw (counter-clock-wise) before inserting end-stop.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on September 09, 2005, 09:53:15 AM
thanks, Jakob.
yes, i can see that the various positions share some things a bit.
guess am being over cautious...

am mounting control board away from front panel (running wires from it to switches) and should have ordered sdr mount switches not pcb variety for this ... pcb variety are a real drag to try to solder wires to.
Title: SSL HELP THREAD!!!
Post by: desol on September 10, 2005, 05:33:14 PM
Hi..:) I don't have a meter yet...
Do i need to have the meter in place for the unit to compress?
I was thinking it wouldn't matter if it was there or not...
Can i put a resistor in place where the meter goes...if i need to...for now?

Thank you...:)

D.
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on September 10, 2005, 05:40:44 PM
just leave the meter out, no resistor etc required.
Title: SSL HELP THREAD!!!
Post by: Sender on September 10, 2005, 07:41:37 PM
Are %1 tollerance reisitors really required for the build or will a 5% do well?
Title: SSL HELP THREAD!!!
Post by: gyraf on September 11, 2005, 03:20:24 AM
5% resistors works alright..
Title: SSL HELP THREAD!!!
Post by: desol on September 11, 2005, 12:54:44 PM
thanks for the reply silent arts... :)
Title: SSL HELP THREAD!!!
Post by: gyraf on September 13, 2005, 04:09:27 AM
What type of +4 signal? A classic "from taperecorder" +4 FSD/analouge, or one of the modern FSD=20dB over +4 d/a converter?

Many modern d/a converters seems to be set at stupidly-high output levels. Send out a full-scale 200Hz tone and measure on your multimeter. Result should preferably be less than 3-4V AC in order to be comparable with the levels we used to work with in the analouge world..

Jakob E.
Title: insane
Post by: EEMO1 on September 13, 2005, 12:48:30 PM
im going insane. i've been troubleshooting my ssl for the last 8 hours or so....


 first i had the low signal/distortion thing going on. changed a few resistors, measured voltages etc.

 now im in a situation where the unit passes a nice-loud signal WITHOUT the control pcb attached. when i attach the control pcb, no signal or anything.

 im open to ideas... please? pretty please?
Title: SSL HELP THREAD!!!
Post by: gyraf on September 13, 2005, 12:51:52 PM
Naa.. it should pass audio cleanly without the control board attached. There's obviously an error somewhere in your sidechain..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on September 13, 2005, 02:53:54 PM
Ahhhhhhhhhhhhh!
Finishing my second ssl.
Trying to troubleshoot a problem i've not seen yet in the forum, though i've scoured meta and forum for anything even slightly similar...
PROBLEM:
Compresses identically,  beautifuly, on both L and R sides
BUT..... (ouch!)
9 - 10db BOOST on L side!!
R side fine.
Regardless in bypass mode or engaged.

- Checked, rechecked, re rechecked all resistors in output section
- Voltages at both 5532s seem good....
- All cap labels look right...(don't yet know how to measure caps)
- Checked continuity of output harness and connector, patchbay, xlr cables.....

2 DAYS later (':shock:') only thing i've found is a bit of "crosstalk" in the continuity on that one connector, though the crosstalk appears identical on both L and R outs... is that normal?

Is it wrong to assume prob is most likely at output section?

Anyone, please.  :roll:
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on September 13, 2005, 04:16:10 PM
check the 15K* resistor at the input of the audio vcas
Title: SSL HELP THREAD!!!
Post by: tree on September 13, 2005, 04:27:27 PM
thanks silent.
it checks o.k.
Any other thoughts real welcome.
getting a little bug-eyed from the magnifyin' glass  :shock:
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on September 13, 2005, 04:41:55 PM
the sidechain path is mono, so the problem must be in the audio path - or in the "dbx 2150 to dbx202 emulation" circuit. check and recheck the resistor values there. if you have a scope you can compare the whole path between the left and right channel.
Title: SSL HELP THREAD!!!
Post by: tree on September 13, 2005, 05:07:54 PM
afraid i don't have a scope.
does it sound loke a resistor issue?
i'd checked all those values prior to installing.
what other sorts of failures might cause a boost like this.
thanks again.
i'd sure be up the creek without the knowldge around here  :thumb:
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on September 13, 2005, 05:23:36 PM
Quote from: "tree"
afraid i don't have a scope.

try to compare the audio path with a DMM, with a low freq. sinus at both inputs.
Quote
does it sound loke a resistor issue?

to me: yes
Title: SSL HELP THREAD!!!
Post by: tree on September 13, 2005, 06:24:19 PM
sorry, dont follow...
Quote
try to compare the audio path with a DMM, with a low freq. sinus at both inputs.

what do you mean by, "low freq sinus at both inputs"?
and how would i compare audio path with my mult meter?
silent,
please have patience with my awful lack of knowlwdge with this stuff  :oops:
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on September 13, 2005, 06:34:21 PM
connect a signal generator, synthesizer, test cd - whatever - to both inputs. you need an input signal to measure / compare. measure the voltage at pin 6 of the NE5534s at the inputs, compare. measure the voltage at pin 1 of the NE5532s at the outputs, compare. measure the voltage at pin 7 of the NE5532s at the outputs, compare.
Title: SSL HELP THREAD!!!
Post by: tree on September 13, 2005, 09:22:01 PM
hey silent -
so i sent a 1k tone to a couple of console rails @ 0db
then to both sides of the Gssl via inserts...

Right side of Gssl returns at unity (on consoles master section meter)
Left side at +9db

the db dif stays the same whether comp is engaged or in bypass

mult meter shows both 5534s PIN 6 = 0
                           both 5532s PIN 1 = 0
                                   5532  PIN 7s = 14.85

adjusting thresh or gain makes no dif to the readings.

 :?
should dc at pin (out) of 5534s = pin 1&7 (outs) of 5532s???
i hope i haven't missed the point entirely  :oops:
thanks again, btw.
Title: still no go
Post by: EEMO1 on September 14, 2005, 05:46:25 AM
pulled everything from the sidechain section, still no go. the audio is low, plus a little distorted. the controls don't work.

 yesterday the channel ne5534's got very hot, maybe i fried them...
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on September 14, 2005, 05:48:27 AM
Do a small test: disconnect the "-" (pin 3) at both outputs. all fine now ?
if yes, check all the resistors around the second opamp of the NE5532.
Title: nope
Post by: EEMO1 on September 14, 2005, 07:11:38 AM
nope, that one didn't have much effect.


 umm... does someone have all the correct ic voltages listed?


 -e
Title: Re: nope
Post by: [silent:arts] on September 14, 2005, 08:24:49 AM
Quote from: "EEMO1"
nope, that one didn't have much effect.

sorry, that one was for tree
Title: SSL HELP THREAD!!!
Post by: tree on September 14, 2005, 10:12:29 AM
thanks silent -

2nd 5532 meaning to the right if facing output section?

can do this afternoon and report back.
really apreciate the quick responses....
Title: SSL HELP THREAD!!!
Post by: tree on September 14, 2005, 04:37:19 PM
silent...

okay, lifted pin 3 at connector, fed both sides tone as above.

STILL 9db hotter on left side. :?

ne5534 PIN 6 = 0
ne5532 PIN 1 = 0
           PIN 7 = 0

does this indicate anything to you????
afraid i'm a little lost here.

any thoughts at all.

checked resistor values with meter as i was originally installing and a 2nd and 3rd time time since - tho only by color code, not meter...
Title: SSL HELP THREAD!!!
Post by: gyraf on September 15, 2005, 03:34:25 AM
tree,

Check (compare) signal levels directly after input amps, e.g. right before the sidechain summing resistors. This shows wether input circuits are alright.

If they are, you have a problem in either VCA's or output stage.

The vca's are kinda integrated into the first output driver stage (the one driving +output) so they are hard to troubleshoot individually. Providing same levels from input stages, compare levels at +out's.

Check (compare) DC voltage at the VCA's control pins.

Check resistor values around these circuits.

Jakob E.
Title: voltages
Post by: EEMO1 on September 15, 2005, 08:23:07 AM
ok, i wrote down my voltages.

 my rails are +14.88, -15.00, +12,07, -12,00.

ics:

input ne5534's pin 4 -15.00 and pin 7 -14.88 on both input ics.

vca section, both ne5534's:

pin 2 -14,78
pin 4 -15,00
pin 6 -14,80
pin 7  14,89

left vca  pin3 -14,80, pin5 -14.94, pin7 14,88, pin8 0,07
right vca the same but pin8 was 0.02

sidechain section

tl072 pin8 12,02

tl074 pin4 was 12,02

sidechain vca pin7 was 12,02 too.

 output ics:

right pin 1 0,03, pin2 0,03, pin4 -15,00, pin6 0,02, pin7 0,02, pin8 14,89

left pin 1 0,08, pin2 0,08 pin4 -15,00, pin6 0,08, pin7 0,08, pin8 14,89.


 any help anyone? im gettig a bit frustrated here...

 -eero
Title: SSL HELP THREAD!!!
Post by: gyraf on September 15, 2005, 10:25:11 AM
eemo,

Input opamp specs looks somewhat wrong. Check that it actually IS 5534's..? Check dc voltages at input and output pins (2,3,6) And check for shorts to minus supply lines in that area..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tree on September 15, 2005, 10:45:07 AM
Jakob,
Quote
Check (compare) signal levels directly after input amps, e.g. right before the sidechain summing resistors. This shows wether input circuits are alright.

... not sure, was yer sage advice meant for my troubleshooting issue or EEM01???
in my case, since both sides compress equally - ratio/attack/release-wise, i was assuming input area must be okay.

wrong though?

...my prob being +9 extra db on left side output.

thanks for anything. :?
Title: SSL HELP THREAD!!!
Post by: gyraf on September 15, 2005, 10:53:13 AM
that last one was for EEMO1, the one before that for you.. edited..
Title: SSL HELP THREAD!!!
Post by: tree on September 15, 2005, 11:18:08 AM
thanks for clarifying, jakob.
Quote
Check (compare) signal levels directly after input amps, e.g. right before the sidechain summing resistors. This shows wether input circuits are alright.


apologies, but i don' have a scope, only small mm...do i need scope for checkin signal here?
it's not dc i'm looking for, right?
And...
the fact that both sides independently compress identical, doesn't rule out possible input section prob, right? :oops:
Title: SSL HELP THREAD!!!
Post by: gyraf on September 15, 2005, 12:08:24 PM
Tree,

You could measure AC at the two resistors. Compression would always be tracking, as we have a single sidechain.
Title: SSL HELP THREAD!!!
Post by: tree on September 15, 2005, 04:23:20 PM
thanks jakob;

does this look right to you?

on the 22ks (off PIN 6 of ne5534) L = -.60, R = -.62
on the 47ks (right before pin 1 of S.C. VCA) both L & R show -.17.
on the 15ks (at top of VCA 2 circuits) i get -.60, -.62

relatively normal?
:green:
Title: SSL HELP THREAD!!!
Post by: tree on September 15, 2005, 04:27:06 PM
correction....
those 22ks, not sure which ones L or R  :green:  :green:  :green:
Title: SSL HELP THREAD!!!
Post by: tree on September 16, 2005, 12:19:04 AM
Quote
Check (compare) DC voltage at the VCA's control pins.

Check resistor values around these circuits.



okay, went back at it....

only dif between L & R vcas that i can find seems to be on PIN 3 (Ec-).
L  = -.05 and R = 0 :?
is dif insignificant at all?

swapped vcas, dif remained....and unit  still +9db hotter on L side.
swapped ne5534s while there too...no change.

pulled and measured all resistors in L vca circuit.... all check right.

so - does this leads me back to output section?

should i just pull it all out and start over??? :roll:
but sooo close...


anyone?
Title: SSL HELP THREAD!!!
Post by: gyraf on September 16, 2005, 04:17:39 AM
Tree,

Your input circuit looks fine from here (If the said voltages are AC! - always tell that explicitly for reference..)

Try removing the two sidechain VCA's, and connect the input to the output on the - now empty - socket with a small piece of wire. That would be pin1 to pin8 - the two outer pins.

This rules out the VCA gains - now check your AC levels at the output - measure AC level referred to ground at both + and - out individually. All four outputs should be close to the same level.

If levels are still different, then check component values, shorts, and breaks at the output stages - that would now be the area where you have the problem.

If levels are now the same, then the small DC voltage at the control pin of one of the VCA's is the troublemaker. Check that area (including the related 5534) for shorts and component values

Jakob E.
Title: SSL HELP THREAD!!!
Post by: EEMO1 on September 16, 2005, 04:27:17 AM
Quote from: "gyraf"
eemo,

Input opamp specs looks somewhat wrong. Check that it actually IS 5534's..?
Jakob E.


 umm, what do you mean by check that it actually IS ne5534's? :D

 -eemo
Title: SSL HELP THREAD!!!
Post by: gyraf on September 16, 2005, 04:29:36 AM
..that marking is sometimes very weak, and often VERY hard to see if it says 5534 or 5532..
Title: SSL HELP THREAD!!!
Post by: quadwould on September 16, 2005, 04:37:45 AM
Hello..  great thread of GSSL all knowingness.....

i have a (or many) issue(s)...

first off. in Bypass when sending a -18dBfs tone, i get an output of -12.. i know this is from the +6 there is in the unit. so that does not woryy me.

What does though is this:  it compresses like an 11*76 in nuke mode,on steriods.  When its engaged,  both channels are really quiet, and with different settings, get even quieter.  the right channel is higher in level (95%) of the time depending on what settings there are dialed in.
it varies , on average, from +6 higher to +22 over the left channel in level.  But even with such differences the overall level is still reallllllly low.  Like -36dBfs and lower most of the time.    i have created an MS Excel spreadsheet that i can email anyone.  it has the dB readings for the left and right channel with the makeup gain all the way down, and all the way up as well  for each possible setting combination of attack and release when the unit is at a ratio of 2:1.   i didnt measure the levels for when its was at 4 and 10 ratio because that was too tedious and i think the problem is not with the ratio as it seems to work.

another strange thing i sthat the higher the input level, the lower the output level.. it iss like its ducking exponentially..  :?

also, the threshold does not seem to be doing anything

and also the meter is pinned all the way up. its  BehR****R meter.  i put the 2K in the main pcb but it didnt seem to help. the 330 does not seem to help either.  

what is the sensitivity of the BerDinger meter anyway?


any help would be very usefull.

i can email the excel file with the level readings to anyone upon request

also i have tried swaping the vcas and opamps from left to right and back again and nothing happened.

if you need to know voltages are specific places, let me know where

cheers guys
Title: yup
Post by: EEMO1 on September 16, 2005, 06:14:29 AM
the 5534 was right. seems like i should get something to pins 2 and 6, but im not... tried to trace the lines to pin 2 and 6 but im not getting any readings.
Title: SSL HELP THREAD!!!
Post by: gyraf on September 16, 2005, 06:26:26 AM
Inverted inputs are tricky to measure, as they're often "virtual-ground" points if feedback is applied (which is the case here)
Title: SSL HELP THREAD!!!
Post by: tree on September 16, 2005, 08:44:57 AM
thanks jakob - really appreciated.
will do.

yes - sorry - should have mentioned that those (after input amp, before sidechain) resistor measurments were AC. :oops:

ability to measure signal with mult meter AC setting valuable info for the very green - personally speaking, of course! :green:
Title: SSL HELP THREAD!!!
Post by: tree on September 16, 2005, 01:43:28 PM
jakob, trouble in the hen house!

before doing the VCA bypass test, i took a look at PIN 3 of L side VCA...
though all joints looked good, i followed the circuit off of pin 3 that led to ne5534 and found apparent solder bridge between ne5534 PIN 5 & 6.
took the chip out and cleaned up contacts, put back in... tested with 1k tone... NOTHING on Left side.... looked closer, in my excitment, i had oriented ne5534 wrong way around!
turned off unit.

reoriented ne5534 correctly.
turned on unit.
POOF.  :shock:
smoke over ne5534 area.
turned off quick.

WHAT HAVE I DONE?????
WHAT SHOULD I DO????
Title: SSL HELP THREAD!!!
Post by: [michael] on September 16, 2005, 02:03:38 PM
Deleted, wrong topic I think. :grin:
Title: xlr wiring
Post by: csonics on September 16, 2005, 02:22:19 PM
Ok, this question will totally indicate my inexperience in all of this but I'm just finishing up my gssl and I am not quite sure how the wiring goes to the in's and outs.  I want to connect the in's to a balanced connection and the outs I want to make balanced as well but with an earth lift if need be.
Does anybody know the wiring scheme for that?  Once again I know that this is totally a green question.  Sorry for the ignorance.
Title: SSL HELP THREAD!!!
Post by: tree on September 16, 2005, 03:02:15 PM
jakob....

okay,

i've replaced the ne5534 that i seem to have fried in L side VCA circuit.
no poof.
no smoke.
BUT
now when unit fed 1k test tone, L side output is even hotter than original problem.  15db hotter not "just" 9db.
AND
when compressing signal, thresh and gain make up pots now have only about 3 db effect on L side output, whilst R side seems to respond as it should.

any idea what ELSE this indicates i may have fried here?????

am sooooooo bummed.

where to begin???
Title: SSL HELP THREAD!!!
Post by: quadwould on September 16, 2005, 09:55:18 PM
Squeak Squeak Squeak Squeak  ... (goes the robot with only 1 wheel)

sounds like Tree and I are having similar problems.

read my above post on page 58 for some fun details. and PM or email me for the excel file

cheers



help....?
Title: SSL HELP THREAD!!!
Post by: tree on September 17, 2005, 02:05:07 AM
Jakob;

BINGO!!! :thumb:

GOT IT!!

A LONG DAY OF TRYING, FRYING AND RETRYING, BUT ANOTHER GSSL IS BORN.

Jakob E. wrote:
Quote
Tree,

Your input circuit looks fine from here (If the said voltages are AC! - always tell that explicitly for reference..)

Try removing the two sidechain VCA's, and connect the input to the output on the - now empty - socket with a small piece of wire. That would be pin1 to pin8 - the two outer pins.

This rules out the VCA gains - now check your AC levels at the output - measure AC level referred to ground at both + and - out individually. All four outputs should be close to the same level.

If levels are still different, then check component values, shorts, and breaks at the output stages - that would now be the area where you have the problem.

If levels are now the same, then the small DC voltage at the control pin of one of the VCA's is the troublemaker. Check that area (including the related 5534) for shorts and component values

Jakob E.


because of your valuable suggestions (100X :thumb: s, Jakob!)  followed PIN 3 trace of L side vca circuit, found a tiny solderbridge at the ne5534 socket.
BUT THEN...
wrongly reinstalled the ne5534 in my haste to test repaired socket - after the smoke cleared, i just replaced any suspicious burnt smelling bits with ones that were identical, but smelled better  :wink:
seems that after my careless backwards chip reinstall poofed :green: , the that vca got ugly too, Left output got even uglier than original prob, but as soon as i swapped in a new 2180 and ne5534 etc....
we was rockin again!

Your GSSL is a beautiful thing -

THANKS AGAIN.
Title: Re: xlr wiring
Post by: gyraf on September 17, 2005, 05:48:34 AM
:grin:  Heey..! Glad that we got that one sorted, Tree..!


--


Quote from: "csonics"
I am not quite sure how the wiring goes to the in's and outs.


Csonics,

Look at the schematic. And look at the component overlay in the pcb-artwork .pdf-file. This is the only way to get a grip ow what the unit does.

And that should make it quite clear how to hook it up: In and out's hot and colds are marked + and - , 0/Ground is marked 0 (on the component overlay and in the schematic)

input xlr's female, output xlr's male

0 to pin1
+ to pin2
- to pin3

Jakob E
Title: im getting pissed.
Post by: EEMO1 on September 17, 2005, 06:16:50 AM
im getting really pissed. im going to desolder everything and start over soon.

 can't find any shorts, wrong resistors or anything. im starting to hate to even look at the damn thing. :evil:
Title: SSL HELP THREAD!!!
Post by: quadwould on September 17, 2005, 04:59:27 PM
Jakob!!!    

Great Sounding Unit!!!!

my issues were all down to 2 tiny shorts with hairline solder bridges.   ARGARGAHHHH.. Silly me for not looking closer....


But Damn.. what a great sounding piece of Kit


Now.. on to tame the threshold sensitivity.

and probably  tame the output too.
Title: SSL HELP THREAD!!!
Post by: FrankSL on September 18, 2005, 09:12:39 AM
Hi,
I've just built a mono version of the compressor, by simply leaving out all right channel components.

The unit seems to work fine except for a strange ratio behaviour: the scope trace of the output signal (with a 1V sine on input) with compression enabled show a weaker signal with 1:2 ratio than with 1:4, which is also weaker than 1:10.

Looks something is reversed... Am I missing anything?

EDIT: I've just found a thread where Jakob explains that this behaviour may be correct with a constant sine signal because the ratio setting changes both ratio and threshold, is this correct?

Thaks,
Frank
Title: SSL HELP THREAD!!!
Post by: gyraf on September 18, 2005, 02:05:57 PM
Hi Frank,

Yes, that's right..

 :thumb:

Jakob E.
Title: SSL HELP THREAD!!!
Post by: FrankSL on September 18, 2005, 02:18:46 PM
Thanks Jakob, that problem was scaring me...  :thumb:
Frank
Title: SSL HELP THREAD!!!
Post by: Luny Tune on September 18, 2005, 06:54:00 PM
I thought I'd try to avoid double posting already discussed problems by reading through this thread. Alas, I stumbled across a little thing that I'd like to have clarified although I hope I'll never have any use for it. I'm talking about the fuse!

The schematic I've checked (the fuse wasn't included in my kit) says that I need a 315mAT fuse for the clone, but earlier in this thread there's talk about a 1A fuse. Well, I don't need additional headroom for meter light or anything so am I right in assuming that the 315mA fuse will be sufficient?

Somehow it strikes me as being upside down to put in a bigger fuse to be on the safe side!?!?:wink:
Title: SSL HELP THREAD!!!
Post by: gyraf on September 19, 2005, 04:16:16 AM
Fuse size depends a lot on your power transformer - and as people are using all sorts of sizes here, it's hard to say anything in general.

For the small on-board type transformers, 250 - maybe even 100mA works fine.

For larger, specially toroid types, you may have to go as high as 630mA to prevent the fuse from blowing at power-up..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Luny Tune on September 19, 2005, 06:28:03 AM
Well, I think the confusing part for me is I thought the fuse was for protecting everything after that point in the cirquitry and that the design of that cirquitry would lead to a certain fuse size required.

Anyways, I see your point as there's a lot of different configurations and preferences out there, so...

With a Dagnall D2185 tranformer I gather I'm good with a 250mA fuse.
Title: oh the agony
Post by: EEMO1 on September 29, 2005, 12:24:21 PM
troubles continue...

 should the 79L12 get hot while the unit is powered? like almost not able to touch it -hot?

 -eero
Title: SSL HELP THREAD!!!
Post by: gyraf on September 29, 2005, 12:44:23 PM
If it still gives you your -12V, it should be alright?
Title: SSL HELP THREAD!!!
Post by: Lowfreq on September 29, 2005, 10:23:23 PM
Ok everyone, just a couple of quick questions.

I've had a read throught the 60 pages of this thread and some searches and found some info. Just wanna double check i'm heading in right direction :thumb:

Firstly, when I got mt GSSL goin, I got too excited and forgot to do the earth @ pin1 input, and I also had my tants on the control board backwards. Got distortion. which is to be expected from what I've read with other probs have had. (AC instead of DC etc etc)
I've now reversed the tants and grounded my input pin1. Still distorting I read that tants may not survive bein the wrong way round. correct?

Secondly, when I was changing the pin on the release switch, all my pins fell of the rotary switches. No prob I thought to myself. But................when I put the ratio one back on for three selections, now only one ratio seems to work, and I'm sure it was fine before that. If I take the pin out again, i get mostly no sound on any of the selections, and only two working ratios, in random spots on the switch. I made sure I had the switch all the way counter clockwise before i put the pin in. weird :?
I checked for shorts & bad solder joints. None that I could see. I looked at the pcb. obviously only the first three pins are actually goin anywhere on the curcuit. arrrrgggghhh!!! :evil: Do I have a bad switch? Or have I done something stupid when all the washers fell off the board?

And lastly, I went and got some new tants from jaycar (codes from Kevs list) but when I got home, they looked real different. No + sign or a longer leg. Thats not a tant then is it? or is it? I double checked the code and all. Maybe the assistant gave me a ceramic? I'll prob just order some from farnell to be sure.

Well, thats my rave over :green: Thanks for listening. I knwo the frist prob has been covered before, but I don't think I've seen my second prob anywhere.

regards

Steve
Title: SSL HELP THREAD!!!
Post by: gyraf on September 30, 2005, 03:55:56 AM
Steve,

Yes, tants will probably fail if they've been put in the wrong way in this application, as they are charging DC.

As you may have read, your distortion could also come from having missed the small pcb jumper just above the connector on the control pcb. Somehow this is often missed in assembley.

For your switch, use an ohmmeter to check what happens, referring to the schematic. These switches rarely fail!

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Lowfreq on September 30, 2005, 10:00:23 PM
Thanks Jakob,

I'm assumin you are meaning the jumper next to the meter +/-. Yeah that one is all good. I'm guessing it must be the tants.

I'll give that ratio switch a good goin over too. If all else fils I'll just go to jaycar and grab a new one.

I'll be glad when it's sorted, coz I can actually hear the compression working, and it sounds really good!! :thumb:  :thumb:
Just that pesky distortion........... :twisted:

Someones gonna get swish happy soon!!!!!! :roll:

regards

Steve
Title: SSL HELP THREAD!!!
Post by: zboy2854 on September 30, 2005, 10:49:30 PM
After having to put aside my GSSL project for a few months, I'm back to working on it again, and I have a really stupid newbie question.

I've got the PCB's all finished, and am ready to start cutting and connecting the wires between the PCB's and switches and connectors.  I soldered on the plastic pin header connectors to the main PCB, and I have the plastic housings and little metal pieces that go on the wire ends and into the plastic housings.  My question is, how should I be connecting the wire ends to the metal pieces?  Do I just solder them on, or is this where I should be crimping, or either or both?  Thanks.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 01, 2005, 06:40:24 AM
Just solder them, and then press them a little together with your pliers. This makes them easier to insert.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 01, 2005, 10:09:58 AM
I'm probably doing this right, but I'm double checking everything to avoid as much trouble as possible.

I see in the drawing that the Bypass switch has A1, A2, C1 and C2 written by it's legs. My Lorlin switch has 1-12 by the legs.

I'm fine using legs 2, 7 and 8, right?
Title: SSL HELP THREAD!!!
Post by: gyraf on October 01, 2005, 10:18:35 AM
Yup - that should be right. If you're unsure, measure the switch with an ohm-meter..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 01, 2005, 10:48:37 AM
Thanks, Jakob.

I could of course check it with the meter (and will to make sure the switch is working, like checking resistor values before stuffing the board) but I'm just slightly confused by what's written on the PCB. "On" and "Off". But that means "Bypass On and Off" and not "Effect On and Off", apparently. So when this switch is in the Off position the unit is not bypassed.

No reply needed if I'm right.:wink: It was just to explain why I asked even though I'm checking the switch with the multimeter as well.
Title: SSL HELP THREAD!!!
Post by: Lowfreq on October 02, 2005, 09:07:44 PM
Hi everyone,

Ok I'm now more confused than ever...... :oops: I changed my tants to some nice new ones. and...........................I don't think they were the problem. Still distorting. arrrgghhh!!!!

It has to be something with my ratio which only seems to get signal on the 1:10 setting. I've checked all the resistors around the ratio (pullin one end of the board before testing) and had a good look at the schem. I checked all the tracks too, to see if anything is lifting. all looks good.

One thing I've noticed is that when I switch from the two non-working ratios to the 10:1 ratio, is that the sound takes a few seconds to fade in. weird. I even put in a new switch hoping that by a long shot the switch was at fault. nope seems to be me at fault. :?

I'm pretty new to problem tracing, so if there's some article I should be reading, then directions would be great.

after lookin & lookin, I just can't seem to see why this doesn't seem to work. It's not the most compicated looking part of the curcuit either. :roll:

I'll try again tonight, but man I'm confused...............

regards

Steve
Title: - Voltages are off at the VCA's
Post by: ReggieReddog on October 03, 2005, 09:37:50 PM
I really hate tacking on another plea for help on this dreaded thread, but.....need a little help.  :oops:

My voltages all seem to be correct everywhere except at the VCA's.  I'm using 2181LB's.  My positive voltage is real close, but the negative voltages are WAY off.  I'm talking like -3 V.  Side chain VCA too.    I check the voltages at the 5534 in front of the VCA's and it is fine.  Without anything in any of the sockets, the voltages at the left and right VCA sockets are correct, but the sidechain VCA socket still has a neg voltage of -8.5 .   Maybe I am going about checking this all wrong.  Quite likely because I am an idiot at this stuff.  Any ideas on what might be wrong or where I should test?

Thanks
Title: SSL HELP THREAD!!!
Post by: dufo on October 03, 2005, 11:01:03 PM
Seems like a hell of alot of prblems with 2181's

215x dont seem to have these issues. Maybe its as simple as wacking a set of say, 2151's in?  :grin:
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on October 03, 2005, 11:05:30 PM
Well, no, I am having the problem before I put the 2181's in.  When I have everything but the 2181's in I am getting a goofy negative voltage reading at the socket where they would be.  So it must be something with the rest of the circuit that I screwed up.  But thanks anyway!


Edit:   Hold up, I think I found it.  After hours of searching and tracing (which is something I am new at) I found a 3K9 resistor that seems to be dead.  It is the one just below the big word "SIDECHAIN" at the top  of the board.   On one side of it I am getting -12V, on the other side of it I am getting -8.6V.  I think its inerds are broke.  That's probably it, right?
Too tired to fix now.....must....sleep.....
Title: SSL HELP THREAD!!!
Post by: gyraf on October 04, 2005, 03:28:28 AM
Reggie,

Take a close look at the schematic - that's the easiest way to trace errors:

- you're not expected to have full negative voltage on the VCA pin.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: chrissugar on October 04, 2005, 04:58:43 AM
Quote from: "dufo"
Seems like a hell of alot of prblems with 2181's
215x dont seem to have these issues.


It has nothing to do with 2181. Most of the problems are from people doing mistakes.

chrissugar
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on October 04, 2005, 09:49:41 AM
Quote from: "gyraf"
Reggie,

Take a close look at the schematic - that's the easiest way to trace errors:

- you're not expected to have full negative voltage on the VCA pin.

Jakob E.



Hmm, maybe I am worrying over nothing.  I just don't know certain things like where I should and shouldn't have proper voltages.   I'll fire her up once I get the cables made tonight and see what happens.  I've had power through it with everything connected and didn't have any smoke, so I don't think I am damaging anything anyway.  

Man I wish I could trace things by schematics alone.  I have to use at least 3 sheets (schematic, parts layout, and circuit board positive) + a certain amount of guessing to figure things out.   Here is a cup of mud:  :guinness:
Title: SSL HELP THREAD!!!
Post by: Sender on October 04, 2005, 06:21:50 PM
Out of curiousity, what does the askterik by the one 1k resistor denotate in the VCA section?
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on October 04, 2005, 08:05:24 PM
Check this out:
http://www.groupdiy.com/index.php?topic=47&postdays=0&postorder=asc&start=90

http://www.groupdiy.com/index.php?topic=47&postdays=0&postorder=asc&start=105
Title: SSL HELP THREAD!!!
Post by: Sender on October 04, 2005, 10:15:19 PM
Thanks, one more question. The cap that is to the left of the aforementioned resistor, is that another 0.1 uF cap? I couldn't find it anywhere on the schemo...

EDIT: I guess left and right really doesn'y matter, it's the cap between the two 1Ks in the VCA section
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on October 05, 2005, 12:02:41 AM
Quote from: "Sender"
The cap that is to the left of the aforementioned resistor, is that another 0.1 uF cap?



Yepper.  You got it.  



And hey guess what!!   I just got mine working and it sounds great!   I'll post some pictures when I get a chance.  Thanks to everyone who helped my dumb a$$.
Title: SSL HELP THREAD!!!
Post by: matta on October 10, 2005, 05:18:49 AM
Hey Guys,

I?m about to order a Torrid for my GSSL Comp and according to the SSL PDF a
4.5VA is what is required for a single SSL Comp, so is it safe to assume a
15VA is MORE than sufficient. RE the secondary voltages, would you
recommend a 18V over a 15V, there is no difference in cost, so I can get
either or.

Thanks

Matt
Title: SSL HELP THREAD!!!
Post by: gyraf on October 10, 2005, 06:28:44 AM
..go with 2x15V 15VA - that allows for juice for the meter light as well..
Title: SSL HELP THREAD!!!
Post by: matta on October 10, 2005, 07:52:07 AM
Thanks Jakob  :thumb:

Will do... looking forward to boxing this unit up, it work so well, I've just not had the time to rack it  :sad:

Cheers

Matt
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 11, 2005, 10:40:33 AM
Another one done today!:grin:

I turned it on.
Found that the threshold pot wasn't active and that only the 2:1 Ratio seemed to allow for compression. Furthermore even the weakest signal created heavey compression. Everything thing else worked fine.

I searched this thread and found out where to look. Couldn't find any solder bridges but scratched acouple of places where I was not 100% sure.

That was it! Apparently there was a solder bridge somewhere in the Sidechain section where I "safety scratched".

I fired up again, and it absolutely ROCKS!! Wow!! What a compressor!

I'm amazed at how tight it holds everything together and how transparent it still sounds. What a design!:thumb:

I've already mixed my first song with it now only a few hours after it's done.

I'd like to thank first and foremost Gustav for assisting so much with both getting all the parts and much help, those who helped me with the few questions I had, and special thanks to Jakob for helping and also for making it available in the first place.

This was my first DIY project and I feel very lucky that it went so smoothly. I can't wait till the next project.:razz: It'll probably be another one of these first but then on to other "stuff".
Title: SSL HELP THREAD!!!
Post by: gyraf on October 11, 2005, 12:47:16 PM
Well done, Luny Tune!

 :thumb:

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on October 14, 2005, 09:19:53 AM
The TYCO knobs for the original GYRAf SSL... Where to buy?
Title: SSL HELP THREAD!!!
Post by: Greg on October 14, 2005, 09:50:33 AM
I buy them from Newark here in the states... they're the PKES series.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 14, 2005, 10:16:59 AM
Newark-through-Farnell in Denmark..
Title: SSL HELP THREAD!!!
Post by: bpatural on October 15, 2005, 11:57:38 PM
Hey guys I've searched around but haven't found an answer to my two problems I seem to have left.  Other than these the compressor seems to be working fine although my meter won't be in til monday.  First off, the auto release seems to be acting a little funny.  When I bypass the compressor it takes about 1 to 2 seconds for the gain to ramp up back to normal level.  Also, the output seems to be 6 db too hot, even in bypass.  I know I Can fix this with different resistors but I'm not sure why it's happening.  My friend who built one of these things actually had his output coming out too low at first.  Any ideas?  This is my first big electronics project.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 16, 2005, 10:53:15 AM
Hi bpatural - your questions have been answered before on several occations..
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on October 16, 2005, 01:32:48 PM
I found this very helpful:  http://groupdiy.silentarts.net/martthie_08/gssl/calibration.html

Although, I think he had the resistors for the meter adjustment backwards.
Title: SSL HELP THREAD!!!
Post by: bpatural on October 17, 2005, 08:34:23 PM
Thanks Reggie.  Forgive me Gyraf.  I looked as extensively as I could.  I replaced the 15K's with 27 and that improved the output gain althoug it's still a little hot.  I seem to have a bigger problem now though.  I'm getting some hard clipping and ring modulation at the tip of the TLO74.  some distortion seems to come into the signal ONLY in bypass mode.  I replaced the chip but still the same problem.  As I turn the threshold control IN BYPASS, it seems to add distortion really low down in the signal.  I checked my solder joints 3 times and they all seem to be good.  Any ideas?  The unit appears to be compressing normally when in, although I know it's not yet right because of the ring modulation.
Title: SSL HELP THREAD!!!
Post by: bpatural on October 17, 2005, 10:11:53 PM
Just found out that this cross talk and interaction with the threshold knob seems to be eliminated if I re-attatch the jumper on the make up bypass.  Any ideas?
Title: SSL HELP THREAD!!!
Post by: deveng on October 18, 2005, 10:19:37 AM
Gentlemen,

I'm currently having a front panel made afor an SSL style compressor nd I'm trying to avoid an expensive call to Sifam from the U.S.!
Does anyone know the correct panel cutout dimensions for the Sifam Type 14 PPM meter as used in the original SSL (and Neve) compressors?  I have 2 Sifam documents, one for the Sifam PPM type 14 and the Director Type 14.  The cutout for te Sifam PPM type 14 shows a 39.5mm hole with 2 mounting stud holes 3mm on a 44.5 mm diameter at 45 degress.  The cutout for the Director Type 14 is a 39.3mm hole, 2 2.4mm mounting stud holes on a 44.4mm diameter.  

The difference is only at most .007" for any of these (other than the mounting stud holes) but of course I want the meter to fit perfectly.  I believe the correct meter is the PPM type 14  1ma FSD (and not the Director Type 14).  But, I want to make sure I have the right cutout for this meter!

Can anyone help on this one?

Thanks,
Jeff
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 19, 2005, 11:16:59 AM
I'm currently mixing a hardrock album with the SSL comp across the mix.

I have a bit of a noise problem on my desk, a Soundtracs MIDI PC 24. It's not a lot but with a lot of new equipment in the studio recently I need to go over everything and ground and balance it all properly. What I do in the meantime is to take down the masterfader a bit and hit the mix buss a bit harder that suppresses some noise and it works just fine. The mixes sound great and the GSSL squeezes like the thighs on a red head I once new. It's all cool! BUT I discovered that when I'm compressing and turning up gain makeup I reach a point where it just won't get louder. On the meter that is. It's like a brickwall limiter or a soft-limiter where you can push it up to give it more loudness.
My question is: Is there a limiting function after the gain makeup? Or is it just me hitting the return of my insert point too hard?
I would think that it's me overloading the return of the insert point, but it doesn't create distortion, it just sounds like it's limiting the signal. And actually doing the job quite well...! That's why I'm asking...

If it IS the returns that are overloaded, could it be that there's a limiting function there?? Maybe it's intentionally in the design because there's no overload indication otherwise at that specifik point. Or what?
Title: SSL HELP THREAD!!!
Post by: deveng on October 20, 2005, 12:09:58 AM
Diyr's

Just in case anyone else has this issue in the future, I made the call to Sifam.  The information I recieved is that the 39.3mm with two 2.4mm mounting stud holes on a 44.4mm diameter at 45 degrees is the correct panel cutout for the PPM Type 14 meter.   I also found out the that the "Director" PPM type 14 and the Sifam PPM type 14 are the same meter.

For those interested, I have designed my own PCB for a SSL style compressor.  It operates as dual mono or stereo.  I made some initial tests using the the Rightmark Audio analyzer through an RME Multiface. The results were good.

Freq. Response: -0.5dB @10Hz and [email protected] 30kHz
Noise Level, dB(A): -105.2
Dynamic Range, dB(A): 105
THD %: 0.052
IMD + Noise %: .419

These were all taken with the compressor "in", 2:1 ratio, 5dB of gain reduction and 5dB of makeup gain.  Not much use to me to test in the bypass mode!  I hope to test again using the Audio Precision Test set to get rock solid measurments and also get rid of the A weighting.  The only one I'm concerned about is the IMD.  Not sure what it should be using THAT 2151 VCA's and 5534AN input, 5532AN output opamps.  In my listening tests the unit sounded very good.

I also designed a hearty power supply PCB to go along with this device.  All works perfectly (so far).  Once I get the panel completed I'll post some pics.  



Regards,
Jeff
Title: SSL HELP THREAD!!!
Post by: deveng on October 21, 2005, 02:46:04 AM
Diyr's

I just recalled that I have not adjusted the symetry pots for the 2151's!  This may explain at least some of the distortion.  I built the circuit boards and didn't touch the pots and I have no idea where they're set to.  So, I'll give a try at adjusting to see if the THD goes down a bit.   This weekend!

Regards,
Jeff
Title: $400 pile of junk
Post by: csonics on October 24, 2005, 07:43:36 PM
Yeah, so I just finished my gssl board, got all connections together, plug in a signal and all I get is a nice distorted farty noise with a litte bit of signal.  I get this on both channels!  I sounds like it gets more distorted and farty when it compresses more!

I got nothin!  Where do I start?  Anybody got any suggestions??

Thanks,

Csonics
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 24, 2005, 08:07:29 PM
Have you checked for solder bridges and orientation of components? And double checked?

If memory serves, there was already someone with a similar problem earlier in this thread. Could have been something with VCAs with wrong orientation...I'm not sure....but check the thread...

I'm a novice myself so I won't even attempt to help you further than that, but I'm sure that's the first thing any of the experienced guys will ask you. So make sure that's done and then post if there's still something wrong with a remark that you did double check the above first. That way they can skip that obvious first somewhere to look and dig into it if the problem is more serious than that.
Title: SSL HELP THREAD!!!
Post by: ReggieReddog on October 24, 2005, 08:09:52 PM
Check the usual stuff like solder bridges etc.  Make sure you have the Sidechain VCA installed correctly (opposite the other 2 VCAs).    Go back through the building process and make sure you put every component in correctly.  If you can't find the prob, just put a pretty front panel on and it can at least look pretty in your rack.   :green:


Hey I have a question of my own:   What are you guys using to measure THD or whatever to know how to adjust the trims?  I downloaded that DazyWebLabs Oscillator, but I can't seem to figure out what I need to do.
Title: SSL HELP THREAD!!!
Post by: csonics on October 24, 2005, 08:59:12 PM
Luny Tune,  thanks for the advice.  I pretty much went over the whole thing.   No solder bidges, and the vca's are in the right direction.

For what its worth, my meter does show the side chain compressing.  And you can here it happening in the audio but what should be a smooth compressed signal is a whole lot of distorted gurgly (sp?) junk.

Any one have any other suggestions?
Title: SSL HELP THREAD!!!
Post by: csonics on October 25, 2005, 10:21:58 AM
Ok, I feel like a moron but I found a jumper that was missing.  I get a LOT more clean signal now but I still get that farty distortion when it compresses hard.  Especially when I set the attack to fast.

Now we're getting somewhere.  Does anybody know what that could be or where I should start?

Thanks again
Title: SSL HELP THREAD!!!
Post by: gyraf on October 25, 2005, 10:34:00 AM
Csonics,

Best advice is probably to read through this thread - e.g. your missing jumper (at the control board, just where the cables come in) has been seen several times before..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 25, 2005, 10:50:05 AM
It does sound like something that's been discussed already I think.

Having said that it should be noted that very fast compressors are actually capable of creating a "farty" effect on some material when you, in case of the GSSL, turn both the attack and release switches fully CCW. It's not a faulty cirquit, but faulty operation for that particular material. With the release mod mentioned elsewhere on this forum you create a release time on the sixth position which i think can create a near-invisible but very effectful compression for a vocal singing, but completely useless for speech because of the farty effect that kicks in at lower frequencies.

I discovered this first with my RNC comps and the SSL comp actually has an attack time twice as fast as the RNC....and that's fast! :shock:
Title: SSL HELP THREAD!!!
Post by: csonics on October 25, 2005, 11:08:18 AM
Gyraf - Your my hero!!  Thanks man.  I will check it out tonight.
Luny Tune -  Thanks for the input thats good to know.

You guys rock!
Title: SSL HELP THREAD!!!
Post by: csonics on October 25, 2005, 07:03:57 PM
Well, the bad news is that I already have that jumper in place.  And...well I guess theres no good news.  I've pretty much surfed through this entire thread and I can seem to find anything.

What else could cause that sort of effect?  Any ideas?


Thanks,
Title: SSL HELP THREAD!!!
Post by: Luny Tune on October 25, 2005, 08:05:05 PM
My limited expertise stops there. Sorry!:?
But I'm sure help is near.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 26, 2005, 02:56:14 AM
Are you absolutely sure that you actually have a malfunction still?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: csonics on October 26, 2005, 09:46:28 AM
Gryaf-  Actually I'm just a dumbass...turns out that the one thing I didn't check was to see if I wired the ins and outs correctly.  I had them reversed- right going to left and left going to right!  It seems to work great now (besides the hum...but I don't have it properly grounded yet).

Out of curiousity now that I have a clear signal to judge, it seems like my gssl has some coloration.  I've never used the original so I can really say what sounds normal.  I notice that the signal looses some of its high frequencies after passing through the unit.  Is this normal?  Is it supposed to have a darker sound?

I'm guessing that the humm could be affecting the signal output too so maybe thats it.

Thanks guys for your patience with me!
Title: SSL HELP THREAD!!!
Post by: csonics on October 26, 2005, 10:18:05 AM
rf,

Thanks for the suggestion.  I don't really mind it that way.  I just want to make sure that it sounds like it was designed to.

Thanks,
Title: SSL HELP THREAD!!!
Post by: csonics on October 26, 2005, 11:23:40 AM
I am using THAT vca's.  Hmmm... something to think about.  The one thing that I noticed is that its dark both with the bypass on and when its compressing.  I would think that there would be little to no effect if the bypass was turn on.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 27, 2005, 04:02:45 AM
..If you take a calculation on the HF stability ceramic caps, you'll see that they're far beyond the audio range. No lack of top-end from this, surely.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: csonics on October 27, 2005, 10:21:16 AM
Guys,  thanks for the info.  I'm taking carefull notes here for future builds.  So from what it sounds like I am thinking I might have a bad cap or something.  I don't notice a lack per se of "hi's" but I do notice a darker coloration to the audio.

Thanks again.
Title: SSL HELP THREAD!!!
Post by: Greg on October 27, 2005, 10:30:53 AM
What type of electrolytics did you use?

In general, I would not describe either of my GSSLs as transparent, so mine have coloration as well. But I don't see that as a bad thing.
Title: SSL HELP THREAD!!!
Post by: gyraf on October 27, 2005, 10:39:36 AM
Yep, I'm pretty sure about the 100p in the emulation part (btw, this is for control-voltage only!)

And the 100p//15K at the current-to-voltage opamp following the VCA gives us a bit over 100KHz bandwidth, which should be sufficient..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: csonics on October 27, 2005, 09:07:08 PM
Just wanted to say thanks guys for all the knowledge you've shared with me.  I've managed to figure out a few more things including some miss wiring.  But I've still got this ongoing problem on my left channel.

When I have the compressor in or on standby the left channel makes this crazy popping noise now. Like when your listening to a thunderstorm on an AM radio without a signal coming though.  Could it be a bad Cap in the signal path?

Thanks,
Title: SSL HELP THREAD!!!
Post by: gyraf on October 28, 2005, 03:07:39 AM
If the problem follows the bypass switch, then look for the dc path from the TL072 through the 202-emulation-5534 and into the CV input of the VCA.

Maybe scope the CV pin of the two VCA's to compare.

Maybe switch VCA's and/or emulation-5534's to exclude broken silicon

Jakob E.
Title: SSL HELP THREAD!!!
Post by: caps on October 31, 2005, 08:28:20 AM
Ok...

Could anyone put me on the trail of where this problem might be coming from..

I have a 1 -2 db difference in the stereo output of the gssl. Strange...

Maybe adjusting the VCA trimmers? Something else ?  :shock:
Title: SSL HELP THREAD!!!
Post by: gyraf on October 31, 2005, 08:47:52 AM
Quote
Maybe adjusting the VCA trimmers


Nope - those are for THD, not level..

That is a large difference (are you sure that it is in the clone?) - you could check tolerances of resistors around the VCA's

Jakob E.
Title: SSL HELP THREAD!!!
Post by: caps on October 31, 2005, 08:50:15 AM
Yeah, going by my soundcards meters , its going out correct levels on left and right, but a difference coming back in!!

Shameful thing is I have had it for ages, though not used alot, and I have only just discovered it. hmmmm.
Title: SSL HELP THREAD!!!
Post by: csonics on October 31, 2005, 12:06:57 PM
Figured it out!  Thanks Gyraf and RogerFoote!  It ended up being a bad connection on the left channel vca.  Both channels seem to work fine now.

Sweet.  On to making the frontpanel.

thanks again!
Title: SSL HELP THREAD!!!
Post by: gyraf on November 01, 2005, 02:51:48 AM
:thumb:
Title: SSL HELP THREAD!!!
Post by: Sender on November 01, 2005, 03:16:16 AM
Quick question. I've noticed my rotary switches fit in two ways. Which way is the proper way.

Thank you.
Title: SSL HELP THREAD!!!
Post by: caps on November 01, 2005, 07:52:09 AM
any reason why gan reduction at a given threshold would be affected by attack times. I.E longer attack results in less GR, is this normal ?
Title: SSL HELP THREAD!!!
Post by: gyraf on November 01, 2005, 08:18:37 AM
Longer attacks results in less coming through to the release circuit, so yes..
Title: SSL HELP THREAD!!!
Post by: Greg on November 01, 2005, 08:26:00 AM
Sender: Either way is fine. The rotaries are symmetric.
Title: SSL HELP THREAD!!!
Post by: Sender on November 01, 2005, 04:53:30 PM
One more quick question....

On the control board there are some things im confused about. On the bottom right corner, there is something silk screened that kinda makes a triangle, what is that and where does it go? Right by that there is somehing else silk screened "ON" "OFF" and "COM" (right below the make up gain pot). What are those three holes for (the holes make a triangle shape, not the silk screened lines).

Thank you.
Title: SSL HELP THREAD!!!
Post by: Luny Tune on November 01, 2005, 05:41:26 PM
I know how you can get confused about the funny lines there. I was too. But have a look at the schematic and PCB layout you can find at gyraf.dk.

There you'll discover that the lines are actually "intentional leftovers" from the description and drawing about how you can either solder in a short right there or leave it open when you connect the bypass switch. (See the mentioned documents for explanation!:wink:)

The On, Off, and Com holes are for the bypass switch to be wired to. And since you got confused over the same thing I did, I might as well tell you the answer to the next thing that confused me a bit.:oops:
Remember that "On" means no compression, and "Off" means compression since we're talking about the Bypass switch being on or off.
You probably got that already, but just in case...:wink:

To give you an idea about exactly HOW those switches work symmetrical, take a good look at the way the bypass switch is wired in the PCB layout .pdf file. Note how the 4x3 switch is described as having A1, A2, A3, B1, B2, B3, C1... pins but on your actual switch the pins are labelled 1-12. The 1-12 is what throws one off as the other way gives you a much better idea about how they're constructed. When in position "1" the middle pins A, B, C, D are connected to A1, B1, C1, D1 respectively (which will on your actual switch be pins 1, 4, 7, 10)... Get the picture?

Understanding these things to some degree gives you power to alter the DIY projects to your likings. You'll find that when you get a good grasp on it, it will also be easier for you to find replacement parts for one project or another, as you will know what functionality to look for.
Title: SSL HELP THREAD!!!
Post by: caps on November 01, 2005, 10:42:28 PM
Quote from: "caps"
any reason why gan reduction at a given threshold would be affected by attack times. I.E longer attack results in less GR, is this normal ?


Intersting! I have only noticed this since taming the threshold in my unit. Id rather it have the full range available at all attack settings, but hey, cant complain.  :grin:
Title: SSL HELP THREAD!!!
Post by: caps on November 02, 2005, 02:53:39 AM
SORRY to ask again, and if Jakob says its normal, that should be enough !!  :grin:


But it just dosent seem right that for a given threshold, the attack AND release times when adjusted in any combination will effect the amount of GR showing on the meter.

Like I said, Im asking once more to see if everyone elses unit does this. Then Ill shut the hell up and accept it !  :grin:  :grin:  :grin:
Title: SSL HELP THREAD!!!
Post by: gyraf on November 02, 2005, 03:23:15 AM
If you take a closer look at the schematic, you will find that the  attack/release resistors - other than effecting the timing in cooperation with the tantalum caps - will also form a potential divider that will affect the absolute level of the signal that passes through. And this in turn affects absolute ampunt of gain-reduction.

This will happen on ANY A/R circuit with passive timing..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: caps on November 02, 2005, 03:47:54 AM
Quote from: "gyraf"
If you take a closer look at the schematic, you will find that the  attack/release resistors - other than effecting the timing in cooperation with the tantalum caps - will also form a potential divider that will affect the absolute level of the signal that passes through. And this in turn affects absolute ampunt of gain-reduction.

This will happen on ANY A/R circuit with passive timing..

Jakob E.


great thank you Jackob. And I learnt something to boot .  :grin:
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 02, 2005, 11:24:54 AM
:?:

I discourvered some weird with my clone today. I have allway used it in a unbalaneded system but today I will try to but it in with some balanced cabels...

After that I powered it up and a lot of noise and hum was running in the system.. Hmmm...

Someone had that experience?????
Title: SSL HELP THREAD!!!
Post by: Sender on November 02, 2005, 11:53:01 AM
Quote from: "Soeren_DK"
:?:

I discourvered some weird with my clone today. I have allway used it in a unbalaneded system but today I will try to but it in with some balanced cabels...

After that I powered it up and a lot of noise and hum was running in the system.. Hmmm...

Someone had that experience?????


Where is Pin 1 (XLR I presume) going. I've heard of people completely lifting the ground or running the ground to earth instead of to PC Board.
Title: SSL HELP THREAD!!!
Post by: Sender on November 02, 2005, 11:59:13 AM
Quote from: "Luny Tune"
I know how you can get confused about the funny lines there. I was too. But have a look at the schematic and PCB layout you can find at gyraf.dk.

There you'll discover that the lines are actually "intentional leftovers" from the description and drawing about how you can either solder in a short right there or leave it open when you connect the bypass switch. (See the mentioned documents for explanation!:wink:)

The On, Off, and Com holes are for the bypass switch to be wired to. And since you got confused over the same thing I did, I might as well tell you the answer to the next thing that confused me a bit.:oops:
Remember that "On" means no compression, and "Off" means compression since we're talking about the Bypass switch being on or off.
You probably got that already, but just in case...:wink:

To give you an idea about exactly HOW those switches work symmetrical, take a good look at the way the bypass switch is wired in the PCB layout .pdf file. Note how the 4x3 switch is described as having A1, A2, A3, B1, B2, B3, C1... pins but on your actual switch the pins are labelled 1-12. The 1-12 is what throws one off as the other way gives you a much better idea about how they're constructed. When in position "1" the middle pins A, B, C, D are connected to A1, B1, C1, D1 respectively (which will on your actual switch be pins 1, 4, 7, 10)... Get the picture?

Understanding these things to some degree gives you power to alter the DIY projects to your likings. You'll find that when you get a good grasp on it, it will also be easier for you to find replacement parts for one project or another, as you will know what functionality to look for.


Excellent response, thank you very much. I love when people give me a response that I learn theory from instead of just 'how to do it'! Thank you very much.

So to further elaborate, can I use a DPDT switch in the situation? In the bypass state I should have "ON" and "COM" shorting and in the compressing state I should have "OFF" and "COM" shorting? Is this correct?

One more question about switches, this time the powerswitch. Do I just put a SPST switch in series between the transformer and PCB (on POS volt?) or do I need a DPDT (both POS and NEG)? Or does the switch go between the IEC and transformer in one of the previous fashions? And what size fuse should I be using?
Title: SSL HELP THREAD!!!
Post by: Luny Tune on November 02, 2005, 07:23:16 PM
Quote from: "Sender"
can I use a DPDT switch in the situation?

I don't know what DPDT stands for. However, it's just a switch. If you'd like the bypass switch to bypass the gain makeup pot too then you need a switch with double action though. That's why the design suggests a 4x3 switch. I'll suggest wiring the suggested switch and then experimenting with the gain makup pot in and out in bypass mode to see what best suits you.

Quote from: "Sender"
In the bypass state I should have "ON" and "COM" shorting and in the compressing state I should have "OFF" and "COM" shorting? Is this correct?

Quote from: "Sender"
Do I just put a SPST switch in series between the transformer and PCB (on POS volt?) or do I need a DPDT (both POS and NEG)? Or does the switch go between the IEC and transformer in one of the previous fashions?

Quote from: "Sender"
And what size fuse should I be using?

These questions all have very clear answers in the schematics, and you can find info here by searching the topics. You'll find this forum an absolute treasure of information just waiting to be absorbed. Just search for the info you need. This is meant in the same sense as what you referred to when you said:
Quote from: "Sender"
I love when people give me a response that I learn theory from instead of just 'how to do it'!

But I'm not sending you away empty handed though so the answers are:
1. Correct
2. NEVER put any components before the power switch. Not even the fuse.
3. I'm using the 315mAT fuse suggested in the schematics. I'm also using the suggested transformer so that's should be fine. When I raised the same question not too long ago (because I didn't check the schematics properly either!:oops:) Jakob informed me that it depends mainly on the transformer, and so I gather that in example if you can draw 250mA from the secondary windings on a suggested transformer in a design, then 250mA should be sufficient even if a different transformer is used for the same design. Somebody please correct me if I'm wrong.:wink:
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 04, 2005, 01:05:10 AM
Quote from: "Sender"
Quote from: "Soeren_DK"
:?:

I discourvered some weird with my clone today. I have allway used it in a unbalaneded system but today I will try to but it in with some balanced cabels...

After that I powered it up and a lot of noise and hum was running in the system.. Hmmm...

Someone had that experience?????


Where is Pin 1 (XLR I presume) going. I've heard of people completely lifting the ground or running the ground to earth instead of to PC Board.


XLR 1 is going to the board and are also connected to a starpoint where the earth from the IEC also is.
Title: SSL HELP THREAD!!!
Post by: csonics on November 06, 2005, 01:18:23 PM
Hey guys,

I'm just finishing up my clone and I wanted to run a few things by you guys.

1.  Can someone verify that this wiring is correct for the in's and out's (balanced):  0 -> pin 1, + -> pin 2, - -> pin 3.

2.  I notice that when I switch ratios my behringer meter doesn't quite show the compression taking place accuratly.  I think...  Well maybe this is normal:  On 1st position (lowest ratio), the meter shows reduction taking place is a bit higher than 2nd position.  3rd position seems right where its supposed to be.
When I listen to the gain reduction everything seems fine.  It just doesn't seem to be reflected as accuratly in the meter.  I checked and double checked all the resistors in the ratio circuit.  They all checkout fine and that is reflected in what I hear.

Is this normal?
Title: SSL HELP THREAD!!!
Post by: Greg on November 06, 2005, 02:23:35 PM
csonics:

Your arrows confused me a bit, but hook up the I/O as follows:
GND: Pin 1
Hot (+):  Pin 2
Cols (-): Pin 3

Regarding the ratio compression... The operation you describe is normal. Jakob has described how the ratio works in the SSL. I'm sure it's in this thread somewhere. I don't remember, and I don't have a schematic handy.
Title: SSL HELP THREAD!!!
Post by: caps on November 06, 2005, 11:01:45 PM
Guys,

I am still having the problem of a inbalance in the level output from my GSSL. I have checked and double checked resistor values etc, all seems correct. The difference between left and right is about 7db!!! :shock:


What could be causes of this, and where can I start to look ? thanks.
Title: SSL HELP THREAD!!!
Post by: csonics on November 06, 2005, 11:19:33 PM
Thanks Greg...

Just wanted to be sure.
Title: SSL HELP THREAD!!!
Post by: caps on November 07, 2005, 12:36:59 AM
Quote from: "caps"
Guys,

I am still having the problem of a inbalance in the level output from my GSSL. I have checked and double checked resistor values etc, all seems correct. The difference between left and right is about 7db!!! :shock:


What could be causes of this, and where can I start to look ? thanks.


actually, its 8.5 db!!  :shock:  :shock:
Title: SSL HELP THREAD!!!
Post by: Jim50hertz on November 07, 2005, 05:41:01 AM
Got my GSSL working yesterday, left channel works a treat, no problem.  
The other channel sounds like it has a phase effect on it and is almost feeding back at higher make up gain settings.

Any ideas guys?
Title: SSL HELP THREAD!!!
Post by: drumtan on November 12, 2005, 03:32:19 PM
this is my version of the gssl , finally managed to take a picture:

(http://www.magix-photos.com/mediapool2/0C/55/85/F0/53/AD/11/DA/8B/6D/D0/F3/D5/06/CF/2F/10/67FF55A053AF11DA8DBF2454D506CF2F.jpg)

(http://www.magix-photos.com/mediapool2/0C/55/85/F0/53/AD/11/DA/8B/6D/D0/F3/D5/06/CF/2F/10/6A8193B053AF11DAB770D0FFD506CF2F.jpg)


it was my first diy project ever and i'm still thrilled about the sound.
it's just fantastic how this thing handles transients and adds punch .
i have no problem with the treshold-range or past-infinity-compression  at all, it starts working at  9 am and shines at 1 pm ,using 2180LB's too.

Added the thrust filter on one of the gssl's and do like it a lot ,especially on the 2bus :twisted:

What i have learned so far:
1. diy is fun
2. metal work is not
3. patience
4. waiting on parts sucks
5. wiring lorlins and pushbutton switches is quite challenging for    somebody with zero knowledge
6. those sifam meters are expensive
7. diy is fun

thanks a lot to gyraf , gustav and everyone on this forum and a BIG BIG thanks to jensenmann
who did spread the diy-virus on me and really helped me with this project ,i appreciate it a lot.

drumtan
Title: SSL HELP THREAD!!!
Post by: [silent:arts] on November 12, 2005, 03:50:22 PM
very nice work drumtan :thumb:
which Sifam meters do you have in ?
Title: SSL HELP THREAD!!!
Post by: drumtan on November 12, 2005, 04:02:23 PM
ppm 14, still with the 1-7 bbc-scale , i didn't bother to change the
scale yet cause i think it's just fine as it is.
Silentarts ,  thank you for the nice "thrust"mod  :grin:

drumtan
Title: SSL HELP THREAD!!!
Post by: caps on November 13, 2005, 08:16:37 AM
The voltage regs get very hot. Any one heatsink them ?
Title: SSL HELP THREAD!!!
Post by: caps on November 14, 2005, 12:36:34 AM
Quote from: "RogerFoote"
Quote from: "caps"
The voltage regs get very hot. Any one heatsink them ?


No. Mine are cool... What secondary voltage do you have on your power transformer?


Cool hey? hmmmm..

15V secondaries here...
Title: SSL HELP THREAD!!!
Post by: gyraf on November 14, 2005, 07:55:19 AM
you'd rarely need heatsinking on the GSSL regulators. yes, they get a bit hot, but I never had them shut down on me.

But don't load the powersupply with current to a meter light - take that before regulation (or best: directly on AC from transformer secondary)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 14, 2005, 04:24:52 PM
What is it with the last letters N, A, AP after the opamps NE5532 and NE5534. Does it mean anything in the projekt?

Best regards
Soeren
Title: SSL HELP THREAD!!!
Post by: smallbutfine on November 14, 2005, 09:44:31 PM
Yes Sören,
the 'A' types are selected NE5532/5534 with garanteed specs. Much preferred in the audio path.
I think AN have even better specs but don't nail me on this... AP? don't know, anyone?

drumtan,
AWESOME design :guinness:  :thumb:
(are you german :grin: ?)


caps,
try changing opamps in the audiopath (test by simply changing from one channel to the other, does the imbalance move?)...i got a similar problem in my alesis comp. is the signal on the low level channel clean or distorted in any way?


Kind regards

Martin
Title: SSL HELP THREAD!!!
Post by: drumtan on November 15, 2005, 05:27:25 AM
i've been told that AN and AP are identical  except for the manufacturer
i guess  P comes from phillips , don't know where the N stands for.

martin alter namensvetter, ja  :razz:  münsterland

drumtan
Title: SSL HELP THREAD!!!
Post by: toffifee on November 15, 2005, 05:49:55 AM
Münsterland, soso! :wink: Münstercity here!
Toff
Title: SSL HELP THREAD!!!
Post by: drumtan on November 15, 2005, 06:31:06 AM
nice to meet another münsterländer !
what a small world we're livin in.
yes , monsterland is the place of the living undead  :wink:

drumtan
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 15, 2005, 09:06:05 AM
Okay... So the letters dont mean anything... This time i ordered some parts i got some opamps with the letter N behind so I thought it mayby would be wrong...

thanks.

Best regards
Soeren
Title: SSL HELP THREAD!!!
Post by: smallbutfine on November 15, 2005, 09:36:21 AM
If N or P are manuf. codes, then N should be National.

Oh mein Gott, das Münsterländer Treffen. Bitte macht jetzt keine münsteraner Volxmusik... :wink:
Title: SSL HELP THREAD!!!
Post by: Sender on November 17, 2005, 11:34:27 AM
I have a quick question about the power transformer. I have the Amveco Magnetics torid from Digikey. I saw what greg posted earlier, but it doesn't make sense. I have tied Purp and Black together, Red and Yellow, Red and Brown together. He said to tie red/brown to the middle of the three, which is ground, which doesn't make any sense. Shouldn't the middle pin of the IEC be running straight to ground? And I'm still a little confused about where all of it goes. Any help would be great, thank you.
Title: SSL HELP THREAD!!!
Post by: Sender on November 18, 2005, 12:04:01 PM
Anyone?
Title: SSL HELP THREAD!!!
Post by: gyraf on November 18, 2005, 12:48:03 PM
We've been over this many times..

I don't know that particular transformer, but somewhere around here thare's a general description of how to figure out transformer wireing (NY-Dave?)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mnats on November 18, 2005, 03:03:11 PM
It's here:

http://www.diyfactory.com/data/transformer_connections.gif
Title: that 9180lc
Post by: ability on November 19, 2005, 04:51:19 AM
Any one ever used a that 9180lc in the design?? i have four of them and three 2150a, but i cant find any specs on the 9180lc. They were shipped to me as a replacement of the 2150a, atleast thats what i remember since it was 2 years ago.

got more time now so i am really going to build it, alreay ordered the pcb's!!

Thanks

 :?:
Title: THAT 2180LB IC sockets? help
Post by: panda on November 21, 2005, 11:58:44 PM
hi! i just started building my Gssl. this is my first! DIY project.
http://www.pliink.com/mt/diy/

anyways. i got some THAT 2180LB VCAs. but i appear to not have any IC sockets for them. i would like to put in some sockets for the THATs. but i can't figure out what i need well looking through the digi-key catalog. :oops:

does anyone know what IC sockets i need?

also, if i understand correctly. since the 2180LBs are "pre-trimmed" i don't need to bend the last connector out of the way? am i right on that? i can just stick them in the IC socket?

thanks!

panda
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 22, 2005, 01:28:24 AM
Quote
does anyone know what IC sockets i need?


Welcome to the DIY world.. great site you have made...

You need a 16 pins socket and then cut it on the middel. Then you got two 8 pins...:wink:

Great luck with the project
Title: sockets, and wire
Post by: panda on November 22, 2005, 03:47:39 AM
wait! i got that.. some 16DIP sockets.. i can just cut then in half? down the center? no problem?
craziness.
thanks..

Quote from: "Soeren_DK"

Welcome to the DIY world.. great site you have made...

You need a 16 pins socket and then cut it on the middel. Then you got two 8 pins...:wink:

Great luck with the project


oh, also can't sleep, thinking about it. i put more pictures up on my site. of my PCBs pretty much fully populated..
http://www.pliink.com/mt/diy/

oh! what kind of wite should i use to wire everything up?
i honestly don't know anything. just jumping in head first here..

thanks!

panda
Title: SSL HELP THREAD!!!
Post by: gyraf on November 22, 2005, 04:22:44 AM
Any wire - though keep away from the heavy ones, as they can be a pita to work with. A split Kat5 network cable works fine..
Title: SSL HELP THREAD!!!
Post by: drumtan on November 22, 2005, 07:36:08 AM
wow...1000 replies in the ssl help thread :shock:
i think jakob just hit the jackpot :grin:
Title: SSL HELP THREAD!!!
Post by: Greg on November 22, 2005, 07:56:33 AM
hi panda:

Nice site, and I'm glad my parts list was able to assist you. As Soeren_DK stated, the 16 pin DIP sockets are to be cut in half and used for VCA mounting !

Regarding wire, I like to use Teflon insulated wire made by Alpha. I buy from Mouser 22 guage.

Keep us updated on the build  :thumb: .
Title: pots and pots
Post by: panda on November 22, 2005, 11:50:29 AM
your part list is/was indispensable! hell, its in front me me right now.

ok, so i was going to spring to for some of this wire. and guess what?
as i was getting parts ready for the pots. i found i never ordered any
50k trim 5x10mm pots! yeah me. anyways. now digi-key doesn't have them in stock, and i can't find them at mouser. can anyone help me out?
i mean im stuck waiting on wire anyways. but digi-keys back order says "1/06" what!?

also, don't i need to some how change some of the switches off your list?
like the 2 x 6 switch? how do i do that?

ps. i cut my sockets, had to file some to get them to fit into place.
but they are in. yeah! i assume i should bother snapping in the ICs and VCAs until everything is together?

thanks again. you guys rock.

panda



Quote from: "Greg"
hi panda:

Nice site, and I'm glad my parts list was able to assist you. As Soeren_DK stated, the 16 pin DIP sockets are to be cut in half and used for VCA mounting !

Regarding wire, I like to use Teflon insulated wire made by Alpha. I buy from Mouser 22 guage.

Keep us updated on the build  :thumb: .
Title: SSL HELP THREAD!!!
Post by: matta on November 22, 2005, 12:16:04 PM
Hi Panda,

Well done on your progress so far. We met over in the Tape Op Forum, and I'm glad to seeing you following through. Great little Blog as well!

Yes, don't bother snapping in the IC's and VCA's till you are done. Actually when you are done you might want to fire up without them socketed just to check all is well. Things happen and if you wires something wrong between to loose a caps or resistor than your VCA's or opamps.

Keep us up to date on your progress.

Cheers

Matt
Title: SSL HELP THREAD!!!
Post by: Greg on November 22, 2005, 01:02:15 PM
Panda:

I read on your blog that you're using the THAT 2180LB VCAs. This means that you don't need the 50K trim pots, as well as some other resistors. There's a thread about it somewhere I think with a diagram of what to remove, but I can describe it to you quickly.

Basically, you want to remove everything connected to pin 4 of VCAs. For the channel VCAs, that's the 68R, the 10K, and the trim pot. For the sidechain VCA, you'll need to remove the 47R.

That should do it !!!  :thumb:
Title: SSL HELP THREAD!!!
Post by: panda on November 22, 2005, 01:13:39 PM
great! so im here looking at my board.. and the gyraf layout file.

witch 10k on the VCA? the one next to the 3k9?

and both 47Rs from the side chain? or just one? if just one. witch one? the one in the next to the 10k? or the other one?

hmm. maybe its the "other one" as its next to the 4th pin.
slowly, i will learn.

pre-emptive thanks!

trevor.

Quote from: "Greg"
Panda:

I read on your blog that you're using the THAT 2180LB VCAs. This means that you don't need the 50K trim pots, as well as some other resistors. There's a thread about it somewhere I think with a diagram of what to remove, but I can describe it to you quickly.

Basically, you want to remove everything connected to pin 4 of VCAs. For the channel VCAs, that's the 68R, the 10K, and the trim pot. For the sidechain VCA, you'll need to remove the 47R.

That should do it !!!  :thumb:
Title: SSL HELP THREAD!!!
Post by: Greg on November 22, 2005, 01:23:08 PM
This should clear things up. Remove the circled components.

THAT 2180 Modifications (http://members.cox.net/capstanrecording/GSSL_PCB_THAT.pdf)

But try to do some circuit tracing on the boards and understand that everything connected to pin 4 is being removed. Also, note the orientation of the channel and sidechain VCAs. The channel VCAs have pin 1 at the top and the sidechain VCA has pin 1 at the bottom.

 :thumb:
Title: SSL HELP THREAD!!!
Post by: panda on November 22, 2005, 05:31:21 PM
thanks for that link to those mods.. i'll do that next.

i have another question. i have 2 2x6 "Rotary Switches"
[mouser: 10wa135]
but the release is suppost to be 2x5. how do i convert one of the 2x6's to a 2x5. i don't get it. remember. i don't know anything.

thanks!

panda
Title: SSL HELP THREAD!!!
Post by: panda on November 22, 2005, 05:50:58 PM
wait. i think i got it.
if i take it appart.. there is like an indented ring inside. that it looks like i could just move to the "5".. its on the "6" right now. so thats probably what it is.. i would wadger!

panda

Quote from: "panda"
thanks for that link to those mods.. i'll do that next.

i have another question. i have 2 2x6 "Rotary Switches"
[mouser: 10wa135]
but the release is suppost to be 2x5. how do i convert one of the 2x6's to a 2x5. i don't get it. remember. i don't know anything.

thanks!

panda
Title: SSL HELP THREAD!!!
Post by: matta on November 22, 2005, 06:04:07 PM
Panda,

Just remove the nut and washer from the 6x2 way switch, Underneat it you will find a stopper, just remove the stop and place it back on the number of stops you want. You can make it a 1 x2 if you want, just find the correct stop (normally numbered).

(After posting this I see you already got it!)

Cheers

Matt
Title: SSL HELP THREAD!!!
Post by: panda on November 22, 2005, 06:16:33 PM
yeah, but wait! more questions. i can't find anything on them.

on the switches.. for the attack and release. how do i know, how to connect the to the PCB? are pins 1/12 let's say.. the "top" ?

then also, on the power supply. i've noticed there are 2 ways of hooking it up. one in the big empty part of the PCB, and other other from the corner connection.. whats the difference?

thanks. if these, or questions like these have been asked and answered. sorry.. i can't find them. this thread is hugh! and the search doesn't seem to work for me.

panda

Quote from: "matta"
Panda,

Just remove the nut and washer from the 6x2 way switch, Underneat it you will find a stopper, just remove the stop and place it back on the number of stops you want. You can make it a 1 x2 if you want, just find the correct stop (normally numbered).

(After posting this I see you already got it!)

Cheers

Matt
Title: switches???
Post by: panda on November 22, 2005, 09:50:22 PM
so i'm working on this switch placement/connection thing. so i made this niffty image. IT COULD BE TOTALLY WRONG!
so the question is.. is it right?

http://pliink.com/gssl/gssl_switches_how.jpg

(http://pliink.com/gssl/gssl_switches_how.jpg)

anyone? i don't wanna solder them down till i know they are in the right place if possible. or if it makes any difference! [witch it seems like it would]

thanks!

panda
Title: SSL HELP THREAD!!!
Post by: Greg on November 22, 2005, 10:11:49 PM
It doesn't matter how the switches solder in the boards. The switches are symmetric. Just put them in there so the set screw doesn't hit the "D" part of the shaft.

I know this thread is huge, but if you read it you will learn ALOT !!!
Title: SSL HELP THREAD!!!
Post by: panda on November 22, 2005, 10:25:05 PM
ok, so what i go there would work?
don't even know what the "d" part of the shaft is.. haha at me.

thanks

panda
Title: SSL HELP THREAD!!!
Post by: Greg on November 23, 2005, 10:47:46 AM
What you drew there will work, but I'm not sure what your numbers mean. The "D" part of the shaft is the flat size of shaft. Look at the switch from the top... notice that it looks like a "D" ... hence, "D" shaft.

Regarding your PSU question... hook the incoming AC at the top right with the 3 pin connector.
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 23, 2005, 11:26:51 AM
@Greg

Thanks for the pdf drawing about the Vca 2180 Lb... I was just thinking about that question today at work... hehe... great.. I ordered 12 stocks from Profusion 3 days ago and the arrived today, Thats quite fast I think...

Soeren
Title: that 9180lc
Post by: ability on November 24, 2005, 04:30:54 AM
i did ask this before but got no reactions, anyone???

Any one ever used a that 9180lc in the design?? i have four of them and three 2150a, but i cant find any specs on the 9180lc. They were shipped to me as a replacement of the 2150a, atleast thats what i remember since it was 2 years ago.

got more time now so i am really going to build it, alreay ordered the pcb's!!

Thanks
Title: SSL HELP THREAD!!!
Post by: kruz on November 24, 2005, 06:03:49 AM
Hi ability,
I'm sorry i do not have any more info about those chips..
but i think you'd beeter send an email to that corp and ask papers about them.
I'm quite sure they would help you out easily.
Title: SSL HELP THREAD!!!
Post by: ability on November 24, 2005, 09:54:48 AM
Thanks, but i did,  :

i mailed that corp with this question :

I started 2 years ago with this project and collected the vca's then i ran out of time so i am starting really now on the project. The thing is i have that 2150a and that 9180vca but the design is for 2150a and then some company shipped me 9180lc. I cant find the specs on them and thinking back there was a story about them that they were not to be sold. can you tell me if they are interchangable with the 2150? Are they pretrimmed and what is the thd of it? I know its better to use them not in a new design (both) but they might make a difference in sound. and if the 9180 can be swapped easily then its worth to try and check out how that one sounds.

Thanks a lot for your time!


 THE ANSWER WAS:

Thanks very much for your inquiry.  The 2150-series of VCAs is being discontinued after over 20 years of production.  We make a pin-for-pin equivalent line called the 2181-series (2181LA, 2181LB, 2181LC) which we recommend for new designs, and which we expect to continue making for many years to come.  This series is available pre-trimmed -- called the 2180-series (2180LA, 2180LB, & 2180LC).  The 2181-series is also available in surface mount (though the pre-trimmed 2180-series is not).

I recommend that you consider the following documents:

2180-series data sheet at http://www.thatcorp.com/datashts/2180data.pdf,
2181-series data sheet at http://www.thatcorp.com/datashts/2181data.pdf
Guide for substituting 2180/2181-series for 2150-series at http://www.thatcorp.com/datashts/dn137.pdf.

This should provide most of the information you need.



I would say thanks for telling me what i already knew, too bad they dont talk about the 9180....... Ques i will be using the 1250 instead!!!
Title: SSL HELP THREAD!!!
Post by: ability on November 24, 2005, 09:56:04 AM
i mean 2150...
Title: SSL HELP THREAD!!!
Post by: mhelin on November 24, 2005, 11:10:49 AM
Quote from: "ability"
THE ANSWER WAS:

Guide for substituting 2180/2181-series for 2150-series at http://www.thatcorp.com/datashts/dn137.pdf

This should provide most of the information you need.



So is there also need for using a smaller capacitor in the I/V converter (the 100 p caps below the 15 k resistors in OUTPUT section on PCB)? The output capacitance of 2180 is 8 pf vs. 30 pf of 2150, and the GSSL uses 100 pf? It's on safe side but shouldn't have any effect on sound, right? The recommended values in datasheets are 22 pF for 2180 and 47 pF for 2150.
~Mikko
Title: SSL HELP THREAD!!!
Post by: tubemonkey35 on November 24, 2005, 12:29:45 PM
I'm starting mine this weekend with 2180LA's I have 2180B's and C's too.
Title: SSL HELP THREAD!!!
Post by: panda on November 25, 2005, 01:18:13 PM
hey,
so monday when i get my power supply, i'm going to hook it up, and hopfully power up! i currently though do not have a meter. do i need to have a meter wired in for it work correctly? i emailed the guy about one of those behrigner VUs, but he never replied. probably cause of the holidays.
same problem with par-metal. damn holidays! ;)

thanks

panda
Title: SSL HELP THREAD!!!
Post by: Greg on November 26, 2005, 06:08:26 PM
You can power it up without the meter. It'll still work fine.
Title: SSL HELP THREAD!!!
Post by: tubemonkey35 on November 27, 2005, 11:26:47 AM
Here's a dumb question....

I understand there is a side chain circuit onthe PCB, but I see that almost everybody only has 2 XLRs in and 2 out? Where or what is used to input the sidechain signal? Or is that most have opted not to use the sidechain feature?

BTW I have a SMART C2 sitting here too! It has 6 xlrs; 2 for sidechain (in dual mono).

I can't wait to a/b the uints.
Title: SSL HELP THREAD!!!
Post by: gyraf on November 27, 2005, 11:39:14 AM
A sidechain is an integral part of any compressor - it's the part that converts audio to control voltage. What you have on some compressors is sidechain ACCESS, allowing you to manipulate signal to the sidechain.

Don't confuse the two things.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tubemonkey35 on November 27, 2005, 11:49:30 AM
Ah... ok kewl Jakob thanks for setting me straight!

So have some of the others here added the input access to it? Just by adding a male XLR on the rear and attaching it to the correct spot on the PCB?

Also what is the latest Rev ofthe PCB? is it Rev 7? I have Rev 7.
Title: SSL HELP THREAD!!!
Post by: radiance on November 27, 2005, 12:50:36 PM
Quote from: "tubemonkey35"
.................So have some of the others here added the input access to it? Just by adding a male XLR on the rear and attaching it to the correct spot on the PCB?
............


Yes, some of us have. Here's how.... (http://www.groupdiy.com/index.php?topic=177)
Title: power supply hookin' up.
Post by: panda on November 29, 2005, 12:25:11 AM
hi,
so i hunted through everything i could on this, here. and my questions may be of sorts that they don't even so much apply to the GSSL. but, if you know someplace else for me to look up the info. that would be great.

i don't know how to hook up my power supply. "."
all my parts are from greg's part list. [US].

what i think i know is. the red and brown wires go togeather into the center hole of the PCB [where the power goes in] and the blue on the "outside" of that. [towards the edge of the board] and the green to the inside. then the red and yellow wires [on the other side of the power supply] go to the jack for my power cable. [and where the fuse is kept]
soo. how do / where do these wires hook up to the jack? and there are 3 places to hook up wires. feel like i missing something.

then the purple and black wire go to the switch? its a rotary switch. where do the wires [witch lugs] connect on that? and do i need to run a wire from the switch to the jack? maybe for the 3rd connection.

maybe if someone has a close up picture. i've been doing alot of monkey see monkey do. but no one has close ups of this part of their builds.

thanks.  :guinness:

panda
Title: SSL HELP THREAD!!!
Post by: Greg on November 29, 2005, 10:49:54 AM
Panda:

Before reading this post, get two things:
1. Schematic
2. Toroid Datasheet - look at diagram
http://rocky.digikey.com/WebLib/Amveco-Talema/Web%20Data/62000%20Series%20Low%20Profile%20Miniature%20Transformers.pdf

First the primaries need to be wired in parallel for 115VAC.
1. tie Yellow and Red together and this goes to the tab label "N" (for neutral) on the fused IEC.
2. tie Black and Violet together and this goes to the 115VAC on the IEC. I think it's the tab just below, or above, the one labeled "N". It's not the tab in middle seperated from the other two. Look at the datasheet for the IEC connector and it should explain it. And don't worry about the switch right now if you're just testing. You can add that later when you put it in a chassis.

Second the secondaries need to wire in series with a center tap:
1. tie Red and Brown together and this goes to the middle pin... this is the "center tap"
2. connect Green to one outside pin and Blue to the other (it doesn't matter which)... remember we're still dealing with AC here so the voltage across the center tap to Green and the center to tap to Blue will be the same, about 15-18VAC. The voltage from Green to Blue will be twice that, somewhere in the range of 30-35VAC.

Presto, that should do it !!!  :thumb:
Title: SSL HELP THREAD!!!
Post by: panda on November 30, 2005, 01:55:17 AM
greg is a hero!
anyways. so i hooked up my power supply. i think. plugged it in.. no smoke [or smells]. so i unplugged it, and i put in all the ICs. and plugged in some cables. [mic outs of my mixer, [balanced TRS i think] into the GSSL. then a mic cable out to the mixer. and plugged it back in. needless to say i got no sound. other then i popping sound when in moved a switch.
the VCA don't really seems to be to much, what i would call, "locked down". they are really wobbly. i could make it pop and click some if i wobbled one. if i hit the XLR connectors it made a cool sound. but then some of the ICs started to get pretty hot. so i unplugged it. have to figure out how to check my power, and then look for solder bridges. i'm sure there is atleast one. but probably more. so, it didn't work. but there are a tons of things i can try. just didn't fire up on the first go. the hot ICs is my first concern, then wobbly VCA, then solder bridges, then was i feeding it a real signal! [i'm pretty much all unbalanced in my studio].. luckly i like trouble shooting. so sleep, work, and back to it!!
thanks everyone so far.  more soon.. pictures of my failure tomorrow night on my blog.

panda
ps. not so much looking for a reply, just a here's what happened report. i know most of these issue's are addressed in this thread already. now for the fun, but not as fun part. well, maybe a, whats up with the wobbley VCA. do i need to trim down the connectors?
Title: SSL HELP THREAD!!!
Post by: matta on November 30, 2005, 02:20:39 AM
Panda,

If you read through this LONG list of posts you will fine you are not the
only one who has trouble. I do feel maybe you were a little hasty in your
power up.

Did you check your Voltages out of your secondaries of the power transformer
before connecting it to the SSL?

Also bear in mind that just because you don't see sparks and flames that you
didn't damage a component or 2, often they short out and die and don't
smoke.

I would go back and check your secondary voltages before you plug into the
board then check the voltages on your regulators, and then also the voltages
on your IC pins, without the IC's. If all checks out well, go back and check
all your wringing, to the board and switches.

All the information on how to do all of the above and what typical reading
are in this thread, you just have to read up some more.

Just work slowly and carefully, double/triple check everything. Odds are it
is small mistake that can be rectified.

Welcome to you first troubleshoot, now the real fun begins and you will
learn a heck of a lot as you go along. Hopefully it ends witha big 'Ah!' as
you figure out the problem.

Cheers

Matt
Title: SSL HELP THREAD!!!
Post by: Soeren_DK on November 30, 2005, 04:41:59 AM
:?:

How is the SSL connected to your setup?
Title: SSL HELP THREAD!!!
Post by: Greg on November 30, 2005, 08:08:22 AM
As matta said, check the secondary voltage on your toroid (this is AC). If that's fine, connect it to the 3-pin and measure the voltages at the IC sockets with the chips removed (this is DC). Look at the data sheet for pin numbers, you can get that from the Digikey site.

Also, the VCAs fit into the sockets nice and tight... if the VCA is wobbly, make sure it's mounted in the socket properly... that is of course, after you know your power supply is working fine.
Title: SSL HELP THREAD!!!
Post by: panda on November 30, 2005, 01:24:00 PM
yeah, i get excitable like that. wanted to run more tests.. but there it was.. i had to put in the ICs, hook up sound and go!! i might have blown something, thats OK. i have a electrical engineer friend coming over to check it out. haha.. i couldn't sleep though.. so i had to!

so i was going to make a custom case for this thing. i was thinking of making the face out of wood. like a par-metal case, just the face replaced with wood! there is no reason that wouldn't work.. and look total cool with the right stain, knobs n' sh*t.. i dont' wanna just put some wood over the metal front.. cause i want it to still be flush in my rack.
though i'm thinking to far ahead. my unit may already be dead!  :shock:

anyways.. now its time to once again read through this thread. i'll find my answers in your guys previous words. exciting times. [ i like trouble shooting for some reason.. maybe its that.. d'oh/ah!! at the end ]

panda
Title: SSL HELP THREAD!!!
Post by: panda on December 02, 2005, 01:03:18 PM
so i have a friend coming over to help out with this thing. yeah me.
i finally do have audio passing. through 1 channel. and the controls seems to do nothing. anyways. i'll figure it out. one thing is weird, that i haven't read anyone mention.

i am blasting through fuse's. now i'm sure it just m touching the wrong thing to the wrong thing with my meters. but like bam, 2 fuse's in one night of tests. could there be a real problem somewhere that i'm not away of. my PS seems to be giving off all the right power. i'm thing i might have some reversed things, or blown ICs.. but the fuse's,, just pop,pop,pop..
is that normal? should i go out and buy like a bag full of fuse's? anything more specific on the fuses beyond 5 x 20 mm?

gonna hook my edgewise meter i got today up today too.. maybe that will do something fun also? like burst into flames!!  :shock:

sadly this might be more fun then actually using it. i know how to use a compressor, and record things.. but this.. it's all new.. like a new GF or something. got figure out the inner workings.

panda
Title: SSL HELP THREAD!!!
Post by: Greg on December 03, 2005, 11:00:09 AM
If you're popping fuses, check for shorts !!!
Title: SSL HELP THREAD!!!
Post by: Flundran on December 03, 2005, 07:16:48 PM
I have no compression on signal. Passing signal thru fine and make-up pot work. Same behavior on both channels. Meter responds when I turn threshold CCW by moving up a bit, frozen in the same position. Output signal then becomes slightly weaker.

TL072 measurements:
Voltage at pin1 at TL072 varies with threshold, and voltage at pin7 varies with make-up pot. However, when I vary the input signal, these voltages is hardly affected at all. +/- 0.05 V at most.

All voltage rails is ok.

/Flundran
Title: SSL HELP THREAD!!!
Post by: panda on December 04, 2005, 03:39:52 AM
ok, so i spent all day on this.
learned allot. but haven't moved forward. i think i found the problem, but can't figure out whats causing it.

on my left channel on pin 4 of the 5534. i get nothing. no 15v. zip. [think / thought it was a short]
so thats just to start in that channel. so of coarse nothing goes right from there.. i have that 2180LB pre trimmed. so i have the 10k and 68r gone, no trimmer. i have been tracing the rails all day. and its just not at the 5534 right. i replaced the socket, and i've tried all my 5534s. i replaced most of the componets in the left channel. other then the 100p thing.
the right channel. has all it power flowing correctly.. so i know my 5534 and VCA are in the right way.

when i do hook it all up. run audio in and out.. of coarse i only get one channel. but its really low singal. and scraggly. and no compression or anything of any sorta, knobs and switches appears to do squat.

so, if the left channel doesn't work. would that effect the right channel?
i have the XLR connected with just hook up wire.. could that be a problem? [for the low / bad signal problem?]
how do i test my ICs to see if they are blowen / damaged?

my rails are cool all the way untill they hit the 5524 on the left. and they appear to be fine everyplace else.

?? lost to the point of.. should i just get some new PCBs and try again? they [the pcbs] are taking some damage from replacing the parts on the left channel..

thanks.  :oops:

panda
Title: SSL HELP THREAD!!!
Post by: emtee on December 04, 2005, 07:09:26 AM
Panda, I'm no expert at this having just finished my 1st Gssl, but one thing that caught me out was missing one of the wire links that carries the +15 rail from one part of the board to another.  I found this when I metered out the Power before installing any of the socketed components. I'm wondering if you've fried a few things when you powered the board up at first as well.

I was very careful to follow the BOM for all the other components, but these links are just shown as lines on the PCB and are easy to miss. I also missed the very small link on the control PCB which turns the compressor into a really crappy fuzz box...

Stick with it, it's definately worth it! :green:
Title: SSL HELP THREAD!!!
Post by: tdstotler on December 04, 2005, 10:39:26 AM
Hello All,

 I just finished my first SSL. Tested all voltages on the main board before
installing the ICs, voltages were good all around.
Double checked for any solder bridges, shorts etc...
Tested everything with ICs.
Unit passes audio perfectly, no hum or buzz, signal is
about the same on output levels.
The main issue I am having is the entire control board seems
non functioning. None of the switches seem to work, even the bypass
and output. The Led faintly glows, and the voltage at the LED is
-2 volts. No meter functions.
 Can anyone give me some pointers on what to trace/check and
if there any spots on the control board that I can check for
some reference voltages.
If I missed something in the posts please forgive me.
 
 thanks

 Todd

www.echoesrecording.com
Title: Hello all
Post by: loz on December 04, 2005, 12:11:03 PM
Just a quick post to say hello to all you techy nutters.
Thought id better introduce myself.
I found this web page a few days ago and i am amazed to see everyone being so helpfull to one another.

I would like to attempt to build the gssl comp as my digi 001 rig would be most happy with some high end gear. all i got at the mo is a tla valve eq.
Not sure where to start really i wanna take it slow and learn exactly what it is im dong while i go along but i dont know where to get the Pcb boards from.

i feel a bit rude in asking for help right away  :? sorry


Loz
Title: SSL HELP THREAD!!!
Post by: panda on December 04, 2005, 12:47:16 PM
tdstotler, have you checked that all your wires going from your main board, to you controls are in the right place? i had mine flipped!
if not all i can say is try to trace your power to and through you board. this is all i am doing.. it may not answer your question. but it might atleast help you pinpoint where the problem may be [though no so much what the problem IS]. sorry thats all the help i can give. since obviously. mine is working less then yours.  :shock:

panda
Title: SSL HELP THREAD!!!
Post by: Greg on December 04, 2005, 01:07:12 PM
hey Panda:

First things first. Get all ICs out of the board until the PSU is working and power is being distributed properly !!!

When you say the left 5534, I assume your talking about the one in the VCA section, not the debalancing one. I'll try and help you this one. Do you have the jumper installed next to the two 47K's... this jumper provides power to pin 4 of the left channel 5534.
Title: SSL HELP THREAD!!!
Post by: panda on December 04, 2005, 02:13:23 PM
Quote from: "Greg"
Do you have the jumper installed next to the two 47K's... this jumper provides power to pin 4 of the left channel 5534.


i totally did that early this morning and cleared up my problem. i just didn't want to already jump in with more problems. so that seems totally fixed. all my rails seem right on now. so popped back in my ICs. and was checking away. and the 5532 in the output.. nearest the edge of the pcb. started to get really hot. so i powered down.. and check the rails again. seemed fine, so i pulled my other 5532 into the socket, and powered up. and IT proceeded to get really hot! so i have no left channel.. at all.  just noise.
but the problems appears to be at the output stage.

my gain and bypass knobs/switches now work. but no compression.
i've tried different VCAs in the side chain. no difference. all my power seems to be running into the controls OK. any idea where to look?

thanks thanks and thanks!

panda
Title: SSL HELP THREAD!!!
Post by: panda on December 05, 2005, 01:50:56 PM
Quote from: "RogerFoote"
Panda

Sounds like the output 5532 might be plugged in backwards?


won't i fry the 5532 is i put it in backwards?
i'm pretty sure it is not though. as its the same direction as the working channel. i just must have a short someplace pulling down the signal.
bla.. talk about lessons in volatage tracing.  :shock:

 :guinness:

panda
Title: SSL HELP THREAD!!!
Post by: Greg on December 05, 2005, 02:26:01 PM
Look at the PCB layout and Jakob put a little "o" that corresponds to pin 1 of the ICs. Also double check the VCA orientation. The sidechain is opposite from the channels.
Title: SSL HELP THREAD!!!
Post by: Flundran on December 06, 2005, 12:42:34 PM
I have no compression on signal. Passing signal thru fine and make-up pot work. Same behavior on both channels. Meter responds when I turn threshold CCW by moving up a bit, frozen in the same position. Output signal then becomes slightly weaker.

TL072 measurements:
Voltage at pin1 at TL072 varies with threshold, and voltage at pin7 varies with make-up pot. However, when I vary the input signal, these voltages is hardly affected at all. +/- 0.05 V at most.

All voltage rails is ok. Have checked resistor values. Is there an easy way to check a capasitor if broken?

/Flundran
Title: SSL HELP THREAD!!!
Post by: Sender on December 06, 2005, 12:43:22 PM
I'm not using the fused IEC so i just bought a regular fuse holder. Do I put the fuse on the 115VAC or the common?
Title: SSL HELP THREAD!!!
Post by: Greg on December 06, 2005, 01:09:45 PM
The 115VAC !!!  :thumb:
Title: SSL HELP THREAD!!!
Post by: Greg on December 06, 2005, 01:19:23 PM
Flundran:
It seems the TL072 is behaving properly, so take a look around the TL074... perhaps a diode in the wrong way?!? And maybe also double check the 10-pin continuity from the main to daughter PCB. Make sure all pins are connected properly.
Title: SSL HELP THREAD!!!
Post by: tdstotler on December 06, 2005, 03:46:27 PM
After doing some testing I am pretty sure my problems are lying
somewhere around the TL074.
Everything up to there seems ok, voltages on the tl 072 and before.
Here is what I am getting from the Tl074

Pin 1 -.43 constant
Pin 4 +12 Volt
Pin 11 -12 Volt
Pin 14 +12 Volt

 I am going to double check all the components around that area,
resolder some connections. Also I notice when I was testing the
TL074 with my tester I would get intermentent sound. I then
lightly tapped the top of the TL074 and got the same thing, sound going
in and out, maybe a bad solder joint?

 One thing I am a little unclear of, where the Bypass switch hooks
into the control board (I am using a Lorlin just like in the
schematics) and I notice a area that shows a jumper line, but I am
unclear if this is to be bridged or not?

 Also does anyone know the correct voltage from Pin 1 on the TL072,
Mine is .45 - 3.09 with the threshold change, is this correct?

 Thanks again for all the help.

 Todd

www.echoesrecording.com
Title: SSL HELP THREAD!!!
Post by: Sender on December 06, 2005, 04:18:14 PM
So I powered up my SSL for the first time. I was getting proper voltage off the transformer. The problem that I'm having is that I'm getting AC instead of DC all over the board, which is very problematic! Is it possible that I have that rectifier mounted incorrently? I have it mounted flat side up with the + in the upper right corner.

Any suggestions?
Title: SSL HELP THREAD!!!
Post by: tdstotler on December 06, 2005, 04:28:29 PM
Yeah  it sounds like rectification at least to my ears. I would double check
the schematic of the rectifier placement. Double check the
AC inputs and outputs of the Rectifer to make sure they are in the proper place, again refer to the schematic.  Also  measure
the voltages at your rectifer, you should be getting AC on 2 pins and DC
out the other pins. If your getting AC everywhere on your rectifier your
rectifier might be bad.
 Try putting in a new Rectifer and see if that solves your problems.
Remember your voltages before the regulators will be alot higher
then normal, which is fine.

 Todd

www.echoesrecording.com
Title: SSL HELP THREAD!!!
Post by: Sender on December 06, 2005, 05:19:28 PM
It appears to be installed correctly. The AC inputs are going where they should be, and the DC outputs look correctly placed, and polarized. So do I Just have a bad rectifier?


Also, is the long lead on a LED the pos?
Title: SSL HELP THREAD!!!
Post by: tdstotler on December 06, 2005, 06:46:52 PM
Yes the long end of the LED is the + postive (anode end),
The shorter is the Negative (cathode end).
If your measurments at the Rectifer are not right  (No DC output) I would
defintly try replacing the rectifier, it cant hurt anything.
If you have a bread board you can take your removed
rectifier and test it there and rule out any problems with the board.
Be EXTREMLEY carefull when working with AC voltages. The
one hand in the pocket rule is a good one to follow.   I make
sure all my AC connections have shrink tube around them and I
wrap some electrical tape around the IEC socket and on/off switch
for good measure just in case.
Title: SSL HELP THREAD!!!
Post by: Flundran on December 06, 2005, 09:10:58 PM
Tonight i did some measurements at the TL074. Are these values somewhat correct? My values at pin 8 seems very "lame"?

With audiosignal fed to left input with threshold pot full CCW:

TL074
pin7
peaks: -0.3 V
silence: -8.0 V

pin8
peaks: -0.28 V
silence: -0.15 V

Some time ago I mounted a TL074 the wrong way. I changed the TL074. But maybe some other components got fried at the same time during this? I haven't replaced any components besides the TL074.
Title: SSL HELP THREAD!!!
Post by: Flundran on December 07, 2005, 12:25:07 PM
I've checked the 10 position connection and it seems allright. I've used ordinary different colored wires soldered directly to the board. I will look up the Flex Strip.

/Flundran
Title: SSL HELP THREAD!!!
Post by: tdstotler on December 07, 2005, 01:57:34 PM
I hear you, I personally try to avoid the molex stuff and go straight on
the board.


 Todd

www.echoesrecording.com
Title: SSL HELP THREAD!!!
Post by: BR on December 08, 2005, 01:14:03 PM
Hey guys,
I asked this on another thread, as some of you may have already seen.  And read through a bunch of pages here but no luck.  So, I repost here to see if anybody remembers anything about this problem without having to search for hours on 70ish pages of threads.
thanks guys.
here it goes:

I read through the meta and couldn't find some that explains the problem that I'm having.
I recently built 2 of these clones (SSL Comp) and both are giving me a little noise followed by a swelling sound after I change Attack and Release settings. I sounds like if the comp is taking some time until adjusting to the new settings.
I thought i might be due to shorting rotaries, but the one's I used are non-shorting.  Should I have used shorting instead??
Did anybody experience the same problem? If so, did you find the answer and the fix for it??
thanks guys

Gil
Title: SSL HELP THREAD!!!
Post by: gyraf on December 09, 2005, 03:35:23 AM
Is it an actual problem? Our 4000E desk does that also to some extent - you'll never change the settings while recording anyway...

But yes, it may have to do with shorting/nonshorting switches.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BR on December 09, 2005, 09:36:24 AM
thanks again Jakob.
I'll try some shorting switches just for guits and shiggles.
Gil
Title: SSL HELP THREAD!!!
Post by: Flundran on December 10, 2005, 09:21:33 PM
I've done some measurements on the TL072 and the TL074 and they both seem right. Should I measure the sidechain VCA also? I have two dbx 202xt as main vca's. How do I measure these for faults?

I would be thankful for a tip or two on this.

/Flundran
Title: SSL HELP THREAD!!!
Post by: Greg on December 12, 2005, 09:52:04 AM
Flundran:

How's the compressor? Let me summarize to make sure I understand your problems. The compressor is passing signal, but you're getting no compression and your meter starts to move but then sticks ?!?

First, since your SSL is passing signal, I wouldn't suspect the channel VCAs to be the problem. I'd expect it to be somewhere in the sidechain. And you stated you feel the TL072 and TL074 are working properly.  And just for clarity, your testing for compression by scoping the output, measuring between pins 2 and 3, not just looking at the meter.

Just something that popped in my head... did you place the small jumper on the daughter PCB? And what VCA are you using for the sidechain?
Title: SSL HELP THREAD!!!
Post by: Flundran on December 12, 2005, 10:22:59 AM
Greg:

The compressor is passing signal thru fine, and the meter is stuck in one position. When I turn the threshold CCW, the meter responds by slowly moving up. When I stop turning the threshold, the meter freezes in position.

I have a jumper next to the make-up pot on the daughter PCB.  I'm using is a dbx 2151 for sidechain.

I haven't actually measured the output, I've listened to it and checked the meter. I'm planning to take the compressor to a friend who has equipment to scope. I only have a multimeter as it is for now.

Should I measure the sidechain vca for faults?
Title: SSL HELP THREAD!!!
Post by: gyraf on December 12, 2005, 11:25:16 AM
there's a short jumper just above the cables on the control board also - common to forget..
Title: SSL HELP THREAD!!!
Post by: Greg on December 12, 2005, 12:56:53 PM
I was referring to jumper that Gyraf stated. It's just above the 10-pin cables on the daughter PCB. Make sure that it's in place. Also, you definitely need to take a look at the output with a scope, with a sine and square wave if possible. If you plan to continue doing DIY projects, a scope is a must-have... X-mas is near, so it's time to treat yourself with an o-scope !!!  :green:

Also, if you keep the jumper for makeup in your unit, your makeup gain will always be active, even when the unit is in bypass. If you want to disable the makeup gain in bypass, take a look at the PCB overlay that Jakob has provided, and it shows how to wire the bypass switch to disable makeup gain. I think this is very important.

But first let's get the unit compressing.
Title: SSL HELP THREAD!!!
Post by: tdstotler on December 12, 2005, 03:20:11 PM
After some troubleshooting I finally found my problem. There is a small
jumper leaving the positive power from the sidechain going into
the control cable + symbol. There was a bad solder joint here and
once correct blammo that thing fired up like a charm.
Compression seems to be fine all around, meter works well.
I feel pretty lucky after reading some of the messages on here
that mine got going pretty easy.
 The main things I tried to do was:
(1) Measure ALL resistors before stuffing in the board
(2) Triple checking all components configuration
(3) Powering up WITHOUT any IC's in the sockets
 
 And finally just tracing the problem to its source.

Ok I am off to play with my new toy! I want to try a 1176 next.

 Todd

www.echoesrecording.com
Title: SSL HELP THREAD!!!
Post by: Flundran on December 12, 2005, 03:47:17 PM
Quote from: "gyraf"
there's a short jumper just above the cables on the control board also - common to forget..


This jumper (next to the meter connections) is in place.


Quote from: "Greg"
If you plan to continue doing DIY projects, a scope is a must-have... X-mas is near, so it's time to treat yourself with an o-scope !!!  :green:


Definitely!  :razz:

Quote from: "Greg"
Also, if you keep the jumper for makeup in your unit, your makeup gain will always be active, even when the unit is in bypass. If you want to disable the makeup gain in bypass, take a look at the PCB overlay that Jakob has provided, and it shows how to wire the bypass switch to disable makeup gain. I think this is very important.


I agree. I'm planning to have a switch on it later on.

/Flundran
Title: SSL HELP THREAD!!!
Post by: BR on December 15, 2005, 07:04:38 PM
Hey guys,
came across another issue with my unit..
The unit is passing signal just fine.  Make-up gain and threshold and meter are working fine as well.
The problem is on the ratio.  It seems as if 2:1 is much higher than 10:1.  It is almost like they are swapped, but not quite.
Besides, checking all the resistors values and checking for shorts and bad solder (all in the control section), what else would you guys recomend checking??  I'm kind of stuck on this.
I did all the testing on keith's Neutrik A2 and Steve's AP, so I know the testing gear is good.
thanks in advance
Gil
Title: SSL HELP THREAD!!!
Post by: Greg on December 15, 2005, 08:54:34 PM
BR:

What you describe is normal... Jakob can give a detailed answer in great detail, but here's the idea. The ratio do some type of averaging or attempts to maintain an average compression when switching between ratios. So, at the same threshold, the 2:1 will have a higher gain reduction than 10:1.  If you want to check your ratios, there's a thread in the META. That is the way to check the ratios.
Title: SSL HELP THREAD!!!
Post by: BR on December 16, 2005, 05:44:45 PM
Cool Greg,
I remember Jakob mentioning something like that, but I wasn't sure how that would affect my testings.  I'll look for the meta and see if I can figure out what is going on.
thanks
Gil
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on December 20, 2005, 01:24:14 PM
Hey guys,

This may have been mentioned here, but I can't seem to find the info I need.

I'm looking for a proper size 100nF Poly (MKT) for the GSSl - the ones I've used previously were always too big and made soldering them in kinda nasty and messy.  Does anyone have a part no for Digikey or elsewhere for the ones I need?

Thanks so much!
Siegfried
Title: SSL HELP THREAD!!!
Post by: gyraf on December 21, 2005, 03:07:56 AM
Use 5mm-types, "2-modules", e.g. the Wima MKS05 100nf/63V
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on December 21, 2005, 12:47:36 PM
Thanks for the reply.  1 question.  What exactly do you mean by "2-modules"?  Do you have a Digikey part no.?  I can't seem to find these.

Thanks!
Siegfried
Title: SSL HELP THREAD!!!
Post by: Greg on December 21, 2005, 04:48:01 PM
I don't think Digikey carries WIMAs. I used some WIMAs on one of my GSSLs, but they were big and some of them had to be glued to PCB and fed with wires. It was a more tedious job, but of the two I have, the one with the WIMAs is my favorite. I also used Nichicon PW caps and DBX 202 for VCAs.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 22, 2005, 03:38:43 AM
Quote
What exactly do you mean by "2-modules"


"Modules" are size-measure for electronic stuff - 1module = 1/10inch = 2,54mm = the distance between two pins in a DIL-pakage IC.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on December 22, 2005, 10:24:35 AM
Gotcha!  Thanks!

Siegfried
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on December 22, 2005, 06:27:02 PM
Does anyone know the exact font that SSL uses on their front panels?

Thanks!
Siegfried
Title: SSL HELP THREAD!!!
Post by: Flundran on December 25, 2005, 12:41:31 PM
Hello all!
I would like to know the normally used input level in volts.

How do I use the trimmers with dbx202 vca's?

I also have a problem with 50Hz noise on outputs when I open the dbx202xt output with make-up pot. (Inputs are shorted while measuring.)

/Flundran
Title: powering up...
Post by: ability on December 27, 2005, 04:47:40 AM
Well i got my hole pcb wired up everything is on it checked all but the only thing i have to do is connect the trafo. Just to be sure i ask this ,

I have 2 outputs with 18 v and 2 with 0 v, now do i connect the two 0v together and put them on the middlle of the three points used for the external power and then the two 18 v on each side?

Do i need to connect the ground of the outlet to that 0v connection point to?

I will start offcourse with emty ic sockets!!!

THANKS

( used a 2 * 18v 15va ) :?
Title: SSL HELP THREAD!!!
Post by: BR on December 28, 2005, 01:08:50 AM
Hey ability,
yes to question 1.  But I'm not quite sure if the 18V will give you problems with the regulators.  All mine were running fine with a 15V traffo running right under that.


Connect the primary to Hot and neutral on the outlet and ground xlrs to chassi ground on the connector.

Hope it helps.
and if it doesn't, its your fault for trusting me...  :green:
Title: SSL HELP THREAD!!!
Post by: BR on December 28, 2005, 01:19:23 AM
OK...
I just did the Ratio measurents on my comp using Keith's step by step directions and got very wackie results.
I made sure I had 20dBs of reduction to get away from the knee and this is what I got:
@ 2:1 -  In= +20dB   Out= +9.2dB ,  gives me a 2.17:1  (good enough)
@ 4:1 -  In= +20dB   Out= +7.7dB ,  gives me a 2.6:1  (crasy)
@ 10:1 -In= +20dB   Out= +6.8dB ,  gives me a 2.95:1 (huh??)

The test was done on a Audio Precision and I'm pretty sure I did it right.
I do have a trimmer in place of the 1K resistors going to the VCA which I trimmed to get the best result on the 2:1 ratio as you can see above.  I was expecting to get at least close to the other ratios, but these are crasy.

Where should I start looking.  I'm running out of ideas.
Any help is extremelly appriciated.   I was trying to finish this one by the end of the year, but it's not looking very good.

thanks again
Gil
Title: SSL HELP THREAD!!!
Post by: gyraf on December 28, 2005, 05:12:33 AM
Gil,

When you change ratio, you change the threshold as well. So it's not easy to measure ratios by simply flipping the ratio switch.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BR on December 28, 2005, 01:43:14 PM
Hey Jackob,
When I was doing the test I didn't just switch the ratio.  I brought the AP level back down (to 0dBu)  and brought the threshold all the way up to 0 reduction and then switched the ratio and brought the threshold down until I was getting 20dBs of reduction again, and then I bumped the AP +20dbu and wrote down the readings that you see above.  
I other words, I made sure that I ran the test like if I was testing 3 different units at the different ratios.
I'm going to recheck all my resistor values, specially around the ratio rotary and the side chain VCA and see if there is anything funky..

In the mean while, anything else I should be worried about?? bad VCA?? Just guessing at this point.

Thanks
Gil
Title: SSL HELP THREAD!!!
Post by: Greg on December 28, 2005, 03:25:19 PM
I would run the test again to make sure. This might not be the problem, but it seems to me that increasing the input by 20dB is a bit much. Try it next time with an increase of 10dB and post your results. I actually used the VU meter on my console for the basic test. Then I went back and took actually voltage measurements to tweak it for more precision. Just to make sure, are you using 20*log10(V2/V1) to get the dB value? If you want, you can just post voltage readings.

If you get the same results, I'd check resistor values around the ratio control.
Title: SSL HELP THREAD!!!
Post by: BR on December 28, 2005, 05:15:56 PM
Hey Greg
thanks, I'll try that in the next few days, I'll post the results then..
In the mean while, I'll check the resistors.

Gil
Title: SSL HELP THREAD!!!
Post by: BR on December 28, 2005, 06:54:41 PM
Just checked all resistor color bands and they all match right to the pcb silks.   So, I really don't know what I did wrong.
I was going to try switching the orientation of the rotary, but I don't think that should matter, since its just changing posts.

One thing is that I'm using the DBX 2001 cans and I didn't populate the 1M resistor and the distortion trim, but I don't think that should matter at all. Since its just for distortion.  Should I short it??

Thanks
Gil
Title: SSL HELP THREAD!!!
Post by: Greg on December 29, 2005, 07:49:08 AM
No don't short it. I'd suggest putting the 1M and distortion trim in the circuit.
Title: SSL HELP THREAD!!!
Post by: FMS56 on December 30, 2005, 04:25:50 PM
This is a little off the subject, but...
I just ordered a Behringer BE46 meter for the GSSL project. Does anyone have any size information on these things? I'm designing a panel with Front Panel Express, and need to know the size and shape of the mounting hole. And whats up with Sifam these days? I was trying to place an order with them, but got no response. Maybe they're off till the new year...

Cheers! :grin:
Title: replacing 2180 with 202c
Post by: mcfate on December 30, 2005, 05:18:30 PM
Hey all,

This has probably been covered elsewhere in the thread, but I couldn't find the exact info.  

I'm a basically non-techie recordist who built an ssl clone monkey-follows-recipe style, and I've used it for about a year and its great.  I recently got ahold of some 202C vcas, and I'd like to swap the existing 2180s.  Can I simply remove the 2180 and 5534 and physically install the 202C over the existing components? Or do I need to unstuff all the existing 2150-related components first?  Also, what about the distortion trimmer - do I leave it or remove it or what?  Thanks a lot!

Gideon
Title: SSL HELP THREAD!!!
Post by: gyraf on December 31, 2005, 02:54:29 AM
Complete Unstuffing is needed..

Why not simply build a new one?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mcfate on December 31, 2005, 05:43:55 AM
And what about the distortion pot thingy?

Building another one is definitely on the agenda.
Title: SSL HELP THREAD!!!
Post by: gyraf on December 31, 2005, 06:17:33 AM
Quote
And what about the distortion pot thingy?


What about it?

If you're asking if it should be removed, then no.

It's not in the under-the-202-area, and you'll need to trim distortion with the 202 as well.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mcfate on December 31, 2005, 02:03:45 PM
Tusand Tak, sir.
Title: SSL HELP THREAD!!!
Post by: shaddai on January 02, 2006, 12:00:10 AM
Found some 50v 3.3pf Ceramic disc caps:

http://www.opamp-electronics.com/~opamp/catalog/index.php?cPath=21_37&sort=4a&page=5

Will they work for the 3.3pf caps on the 9k project? :roll:

Todd
Title: SSL HELP THREAD!!!
Post by: gyraf on January 02, 2006, 05:02:55 AM
Todd,

This is the ssl-compressor-clone thread.

But yes, I think ANY 3p3 will work for the 9kMicPre.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: shaddai on January 02, 2006, 02:12:33 PM
Oooppps. My bad..just saw SSL..
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on January 02, 2006, 03:34:13 PM
I'm looking for a single inline ribbon cable(10 in total) and connector to join the main and control board PCB's for the G-SSL.  Unfortunately, I've only been able to find the dual pins (20 in total).  Does anyone have a part number or know where I can locate in the US or Canada?

Thanks.
Siegfried
Title: -16,8 volt
Post by: ability on January 03, 2006, 06:53:24 AM
After hooking up my trafo, i got a nice 12.1 v/ - 12.0 v and a nice 15.1 V however the - 15 volt was -16,8 V !!!

Now i already replaced the 7915 for 3 times now but the value stays about the same. When i measure after the bridge rect. i get on both sides 26,3 Volts. I dont get it , CAn the 1000Uf cuase this? its the only thing between the 7915 and the bridge.

Or is my input voltage way too high for the 7915, i bought a 2 x 18 V wich when i measured gave me 2 x 20 Volts

Any one??

I did measure this without any ic in the circuits, that doesnt matter right?
Title: SSL HELP THREAD!!!
Post by: gyraf on January 03, 2006, 07:55:37 AM
Mounting IC's could matter - regulators behave best under moderate load. Chip in, and recheck.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: ability on January 03, 2006, 09:38:30 AM
Thanks that made the difference!!!!!

 i have put the ic ;s in and voila there was my -14.9 V. Hooked everything up and audio is passing, not sure if all is working like it should be but i have to listen on speakers later, i am now on headphones!

only a litlle itchy hum is in the back but i did not connect any earth to the board yet so it will go away...

Going back for testing. THANKS AGAIN!!!
Title: SSL HELP THREAD!!!
Post by: gyraf on January 03, 2006, 12:35:45 PM
:thumb:
Title: VU Meter
Post by: Siegfried Meier on January 04, 2006, 01:19:21 AM
I can't seem to find anyone that is selling the Beh*inger meter.  Does anyone have any they are selling?  DBM Pro Audio doesn't seem to be replying to any emails.

Also, anyone know of a ribbon cable and connector I can use for the G-SSL?

Thanks,
Siegfried
Title: SSL HELP THREAD!!!
Post by: BR on January 04, 2006, 10:16:56 AM
Hey Siegfried,
Just try to call them if you can...

As for the ribbon cable, I just bought some Molex and wired it myself.  Work out pretty well.  Specially for removing the control board for checking for problems.
 take care
Gil
Title: SSL HELP THREAD!!!
Post by: khstudio on January 05, 2006, 11:17:21 AM
I'm sorry to jump to the end but this thing is looooooooooooong.

Is there a US parts list yet & who has the PCB's in stock now?

Are there any differences in the PCB's offered? I noticed a few guys are making them.


Thanks, Kevin
Title: SSL HELP THREAD!!!
Post by: Greg on January 05, 2006, 11:25:23 AM
Check the SSL Meta... there's a direct link to a parts list in the US. And all the boards are the same, as far as I know. I've built from the Chef's as well as Gustav's.
Title: SSL HELP THREAD!!!
Post by: khstudio on January 05, 2006, 11:34:23 AM
Cool :thumb:

Whoever has boards in stock let me know!
Title: SSL HELP THREAD!!!
Post by: BR on January 05, 2006, 11:35:37 AM
Hey Kevin,
I have a parts list laying around, but I used some pretty fancy switches and stuff.  change it to your liking.  Just PM or email me.
gilparente AT yahoo DOT com.

Check this thread for pcbs
http://www.groupdiy.com/index.php?topic=10776

happy diy
Title: SSL HELP THREAD!!!
Post by: trancedental on January 07, 2006, 02:18:13 AM
Hi Guys, Newbie alert :oops:

I'm just trying to put an order together for a GSSL clone.

Can you answer a few questions?

1. Which THAT2180 should I get? Are they all compatible?
https://www.profusionplc.com/product-frame.htm I assume the LC version is OK?

2. Which NE5534 ? there are no AN's available?
http://uk.farnell.com/jsp/endecaSearch/searchPage2.jsp?Ntt=NE5534&newSearch=true&Nto=sifam+meter&Nty=1&showImages=true&N=401&Ntk=gensearch#results

3. Is this the right meter? Does it fit in a 1U 19" rack case?
http://uk.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=969746&N=401

Also is there a up to date UK or Europe BOM as the one I tried to use (Rapid SSL) has a lot of parts missing due to changing stock codes?

I would like to know what you recommend for a 1U rack case as well?

Sorry for being a pain :green:
Title: SSL HELP THREAD!!!
Post by: radiance on January 07, 2006, 08:42:53 AM
1)  I took the THAT2180LB and it works very well for me. It's pre trimmed so you don't need a distortion meter to set it up. The THAT2180LA has better specs but is also more expensive. The THAT2181LA /B/C are user trimmable and have even better specs than the pre trimmed versions.

2)the NE5534AP will do....

3)I think it does. You can find the exact measures in the data sheet.
Title: SSL HELP THREAD!!!
Post by: therecordingart on January 07, 2006, 05:53:17 PM
Sorry guys....I just posted this in "The Lab" without even thinking to ask in here....

Here is my issue....my SSL powers up, passes audio, the makeup gain works, and the bypass is defeating the make up....things are looking good.  BUT, all of the other functions don't work, and neither does the meter!  

On the layout I was confused with the bypass switch and there are two wires that go to A and A2 on the bypass switch.  On the board it looks like I'm supposed to place a jumper between these two connections, but I was confused so I didn't do it.  

Could this be the issue? Should I connect a jumper?  Did I place my rotary switches in backward or something?
Title: Stupid question- Led's in series or parallel?
Post by: peeceebee on January 09, 2006, 10:03:02 PM
I'm going to use several led's to light my meter and also as the power on indicator-
I assume I can pull them all off the feed for the pilot led on the daughter board-

BUT- do I wire them in series, or parallel, between the two PC points?
AND would any extra resistors, etc. be needed to be inserted in the circuit?

(Sorry if this is a stupid question- I'm more of a solder jockey than an electronic theorist...)
Title: SSL HELP THREAD!!!
Post by: CJ on January 09, 2006, 10:25:13 PM
you will add up the forward drop voltages of the LED if you use them in series.

they each chew arounf 1 ½ volts a piece, so you need to limit your
series string to 12 / 1.5  then subtract one LEED so you can replace it
with a series limiting resostor, which will chew up some amount of
volts deoending on which led you use and how much current you
feed it.

my inglsh ok?
Title: SSL HELP THREAD!!!
Post by: W DeMarco on January 10, 2006, 08:29:26 AM
Quote from: "Greg"
Tubejay:

My toroid is actually an Avel from Parts Express, but yours will do just fine. Here's what you need to do to wire it.

On the primaries:
Tie yellow and red together and that goes to your common (not GND).
Tie black and violet and that goes to the hot (115VAC/120VAC).

On the secondaries:
Tie red and brown together...
Then measure between green and blue and you should have approximately 30VAC.

When you go to connect to the Main PCB, the red/brown (which are connected together), go to the middle point of the three. Connect green to the outside and blue to the one on the inner part of the board.

Basically we're connecting the primaries is parallel and the secondaries in series.

Let me know if anything is unclear.


Just wondering what is actually happening when you tie different leads together.  Could you explain that.  I used the same transformer so this post helpful to me.

Love the forum, my addiction has begun!


Will
Title: SSL HELP THREAD!!!
Post by: Greg on January 10, 2006, 10:38:44 AM
Take a look at the datasheet for the toroid and it will make more sense. The primaries can wired in series or parallel. IIRC, series is for 240VAC and parallel is for 120VAC. Similar thing on the secondaries...  they can be wired in series or parallel. In series, double the voltage and half the currect. In parallel, you get twice the current. I think that's basically it.
Title: SSL HELP THREAD!!!
Post by: khstudio on January 11, 2006, 11:35:51 AM
I'm down to my last few components to order & need help.

I'm using this build as a reference:
http://groupdiy.com/index.php?topic=12612&sid=2ecf3d6f09012820eb9bfe67fa05769c

Not only does it look cool but seems to be laid out very well with the addition of the side chain. As you can see there's not much room for large Power & Bypass switches.

In the pics he uses some sort of mini toggle... but what type & does anyone know where to find them. I'm really confussed about:

Power switch:
   # of poles = ?
   # of throws = ?

Bypass switch:
   # of poles = ?
   # of throws = ?

The parts list I'm using is Greg Steins & it recommends 4x3 for both :?
WHY 4x3...are that many polls or throws needed & for what?

Thanks, Kevin
Title: SSL HELP THREAD!!!
Post by: gyraf on January 11, 2006, 11:54:59 AM
- Only two poles needed.

- The Lorlin type signal wsitches can be "programmed" to reduced number of steps - do a search here.

- Use a REAL mains switch for power, not the flimsy signal switch that is used on the pcb. Dosen't matter if it's one- or two-pole. Lorlin makes a good rotary power switch, available from RS.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on January 11, 2006, 12:15:01 PM
Gyraf,
Thanks man:thumb:

There's not much room on the front with the added sidechain & I thought that one was laid out well. Wouldn't a rotory be too big?

Also,
I'm not new to DIY & component types but I am to PCB's & the SSL.
What types of caps were used in the original? I've heard & know the difference of Poly & Metalized Poly but once again...not in this unit. Does either type end up on top (sonically) & which do you (or anyone) prefer in your the clone?
Title: SSL HELP THREAD!!!
Post by: khstudio on January 11, 2006, 12:19:50 PM
BTW, I wanted to use LEDs under the swithes like he did. Does that affect the amount of polls needed? How should I hook up the different switches? (includine the LED's)

I'm so exited to get this thing done & start using it in my studio.
 :grin:
Title: SSL HELP THREAD!!!
Post by: jordanosaur on January 11, 2006, 04:06:05 PM
Hi all -

I'm new to the forum, and I have just received most of my components I orderes using Greg's parts list (thanks Greg!).  My only concern is the .1uF polyester caps (digikey part# P4593-ND).  Not only do they look different than the caps used in the pics posted on the forum, but the size of these is too big for the layout on the PCB.  I double checked the parts numbers on the BOM and my digikey order, and everything seems to be correct.  Is there a revised part number you guys are using for the same cap. in a more compact package?  

Here's a semi-crappy picture of the caps I received:

http://i39.photobucket.com/albums/e158/jordanosaur/Jordanspictures001.jpg

I tried to search for this topic and could not find anything, so I kind of assuming I have the wrong caps.  Any help or advice would be much appreciated!

Thanks everyone

Jordan
Title: SSL HELP THREAD!!!
Post by: Greg on January 11, 2006, 04:51:20 PM
hi Jordan and welcome to the Lab.

Those are polyesters... I think many people used metalized polyesters (rectangular looking). I've used those Panasonics before, and they'll work just great. Just bend them a little if need be. Happystuffing.

(http://members.cox.net/capstanrecording/GSSL/G4000_2180_Top.JPG)
Title: SSL HELP THREAD!!!
Post by: khstudio on January 11, 2006, 04:57:47 PM
Besides the other stuff I need help with...

What should the fuse be?
.315ma Slo-Blo?
Title: SSL HELP THREAD!!!
Post by: toffifee on January 11, 2006, 07:49:43 PM
Quote from: "khstudio"
BTW, I wanted to use LEDs under the swithes like he did. Does that affect the amount of polls needed? How should I hook up the different switches? (includine the LED's)

I'm so exited to get this thing done & start using it in my studio.
 :grin:


Hello Kevin!
You are talking about the unit I made, so I can answer this:
Yes, to switch the Bypass-LED I used a 3-Pole. You can feed this LED (via the third pole of the switch and an additional resistor) from the same point of the PCB from which the power LED is fed.
The power LED is fed directly (the resistor for this LED is already on the PCB) from this point, so it will shine when the whole unit is switched on. So no need to have more poles on the mains-switch.
You don´t need a rotary-switch as mains-switch, but you could, if you wanted. IF you wanted to use a rotary for mains, THEN make sure you don´t use the standard lorlin for that - they are not rated for mains. That is (if I understood right) what Jakob also wanted to point out.
Happy DIY :guinness:
Toff
Title: SSL HELP THREAD!!!
Post by: khstudio on January 11, 2006, 07:59:59 PM
All good stuff. Thanks again.

Bear with me I'm almost there...
could you send me the pdf you were talking about?

or

Help me with the other questions I had on the previous posts.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 16, 2006, 08:06:46 AM
Hi everybody

I've build a SSl compressor using the chef's PCB and Kev's part list.

But now I've got some problem with it. The unit doesn't work...  

When I powered the unit, all seem OK, no smoke, no special smell, the power on LED is working and the tension (+12/-12; +15/-15) are OK

When I pass audio thru the unit, all is alright, the sound isn't distorded and I haven't any hum.

But, the control aren't active, the bypass switch, the ratio, attack, release and threshold pot doesn't change anything, and the meter doesn't show anything at all.

The Make-up knob is working, the volume change but only on the rigth channel !!!! nothing change on the left one....    

I've checked the PCB but havn't found any shortcut...

Do you have any idea of what's happening???  

Thanks
Title: SSL HELP THREAD!!!
Post by: nrgrecording on January 16, 2006, 08:26:41 AM
Nadege,
maybe there is a problem with the input/output connections?
Thats what happened to me in the beginning.

(http://www.nrgrecording.de/tempfolder/ssl_input.jpg)

Balanced input is: + - GND - +   Output is: - + GND + -

Or have you mixed the NE5532 and NE5534? Is the VCA correct (pin1) ?
You could try to connect "IN" and "OUT" at the vca with a small peace of wire (remove the vca first) to check if the input/output circuit is working. (i think pin 1 is IN and pin 8 is OUT [take a look at the datasheet first])

Good luck.

Frank.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 17, 2006, 04:34:54 AM
I've checked my connection and all seems alrigth,  for the link between the control PCB and the main PCB and the IN/OUT connections.

All my IC are the good one and in the rigth place and in the rigth orientation.

Don't know what's going on...

I'll made some measure tonigth..  :evil:
Title: SSL HELP THREAD!!!
Post by: Greg on January 17, 2006, 07:59:51 AM
Just for clarity, did you check continuity between the main PCB and control PCB? or just visually inspected it?
Title: SSL HELP THREAD!!!
Post by: Nadege on January 17, 2006, 08:48:36 AM
I checked the continuity using my "multi meter" in the continuity mode.
Title: SSL HELP THREAD!!!
Post by: peeceebee on January 17, 2006, 08:22:49 PM
I just completed my gssl, and there is a problem somewhere in the sidechain.

The unit passes signal, and the makeup gain switches in with the bypass. BUT nothing else is active, no meter, gain reduction, etc.

When I feed a 1k 0db signal into the unit, it shows up on pin 7 of the tl074, so it's getting at least that far through the sidechain vca- but somewhere past that in the sidechain circuit there's a problem-

MY problem is that I don't understand what the voltages should look like at each stage of the sidechain, under various control configurations, so I don't know how to troubleshoot it with a scope- I don't really understand what the circuit is supposed to do-
Specifically, for a given ac voltage output from the sidechain vca, what should the voltages/waveforms look like at the output of each stage of the tl074?

Has anyone done a table of what sample voltages should look like at various points of the (sidechain) circuit under different conditions?

Many thanks for any help-
Title: SSL HELP THREAD!!!
Post by: peeceebee on January 17, 2006, 09:23:36 PM
As an addendum to the previous post, what should the threshold voltage feed look like further "downstream" in the circuit as it's varied, at pin 6 and/or pin 7 of the tl072 and other places for example?

An inactive threshold would account for my symptoms-

It doesn't seem to be doing a whole lot on pin 6(?)
Title: SSL HELP THREAD!!!
Post by: Nadege on January 19, 2006, 10:31:43 AM
Hi guys,

I've rewired the main PCB to the control PCB, checked all the resistor and cap value, redo some pretty ugly soldering point.

Before putting back all the IC to their socket I checked the tension all across the board and now everything is perfect except for the tension of the NE5534 of the DBX 202 emulation circuit.

Normaly the rigth tension for VCC+ and VCC- of the IC is  +12v (pin 7) and -12v (pin 4) and now I've got +15v and -15v. Is there something wrong?

I really don't know if it's Ok or if I'll have to check something else before putting the chip back to place... It's my first DIY project and I'm not really good... :cry:

Thanks guys for your advice.
Title: SSL HELP THREAD!!!
Post by: gyraf on January 19, 2006, 11:15:20 AM
Quote
Normaly the rigth tension for VCC+ and VCC- of the IC is +12v (pin 7) and -12v (pin 4) and now I've got +15v and -15v. Is there something wrong?


..Try tracing the copper traces from those pins to the regulators in the powersupply..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 19, 2006, 12:30:46 PM
I traced the signal but suddenly the tension change and now I've got -17v and +12v !!!!  And it's really less stable. I think something burned... But I didn't notice any smoke or strange smell.
 :?:  :?:  :?:

On the other hand, I'm a bit confused about this trace... I don't understand what is in the way of +15/-15 v to the Ne5534 of the DBX emulation to bring it to +12/-12v ??? (All I see is that the way is really simple, is just a straight way from the point with +15v to the pin 7 of the ne5534 without any component in the middle)

I'm not sure I'm clear because of my english :?
Title: SSL HELP THREAD!!!
Post by: gyraf on January 19, 2006, 12:43:44 PM
Quote
-17v and +12v


Something is wrong.

Check (and possibly replace) your negative regulator(s)..
Title: SSL HELP THREAD!!!
Post by: Nadege on January 19, 2006, 01:50:06 PM
How should I check it? Is there a special procedure?
Title: SSL HELP THREAD!!!
Post by: gyraf on January 19, 2006, 02:43:00 PM
Nope.

If you're unsure, try replacing with a known-good specimen..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 19, 2006, 03:02:09 PM
I replace the 7915, 7815, and 79l12 but I still have the same trouble, i.e around -17.5v and around +11.22 v I looked for shorts, but couldn't found anything wrong. :cry:  :cry:  :cry:  :cry:


Thanks for your help Jakob
Title: SSL HELP THREAD!!!
Post by: Nadege on January 20, 2006, 05:44:23 AM
Ok I checked the trace again looking for shorts, and now I'm back to the original situation, no +12-12 at the ne5534 of the vca emulation but +15-15

Grrrrrr... :evil:
Title: SSL HELP THREAD!!!
Post by: gyraf on January 20, 2006, 05:58:47 AM
Take another look at the PCB..

The VCA emulation driver opamps are connected to the jumpers marked +15 and -15.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 22, 2006, 04:27:37 AM
Ok, I had another look, all seems to be ok exept for this +15-15 of the NE5534 of the VCA emulation.

Could anybody explain how the tension +15-15 is put down to +12-12 in this circuit. I'm totally new at DIY and don't really understand this part of the schematics.

For me, I only see the +15-15 v rail witch is feeding directly the ne5534 whitout anything in his way.....

I think I'm going to build a second clone to see what's happening..

Thanks guys
Title: SSL HELP THREAD!!!
Post by: gyraf on January 22, 2006, 07:18:24 AM
I don't understand why you expect anything other than +/-15V at those opamps, when it's clear to see (if you inspect the pcb) that they ARE CONNECTED to the +/-15V lines?
Title: SSL HELP THREAD!!!
Post by: Nadege on January 22, 2006, 12:13:01 PM
just because on the schematics is see that the tension must be +12/-12. Is there something wrong in the schematics?

I'm using the schemativs from Gyraf and it's in the little box on the left down the page "VCA emulation"

Maybee all is alrigth after all...
Title: SSL HELP THREAD!!!
Post by: gyraf on January 22, 2006, 12:24:13 PM
Yes, the schematic says +/-12 at the vca-driver opamps, where it should say +/-15.

Quote
Maybee all is alrigth after all...


You bet..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 22, 2006, 12:33:49 PM
Fine, I'm really happy  :grin:  :grin:  :grin:  :grin:

nearly becam mad because of this.

Thanks Jakob Now I'll see what happens with the IC in place and with audio going thru the unit, Hope all is going to be ok

 :wink:
Title: level problem with one channel
Post by: indigom on January 22, 2006, 04:42:28 PM
Hello all,

 I'm trying to get a second SSL board working.   It passes audio and compreses, meter works, but one channel is a few db lower that the other on all input audio.

It happens the same even in bypass.

Here's what I've done to troubleshoot so far:
-I've resoldered the input/output connections at jacks and checked the + - orientation on my connectors and they seem fine.   Verified connectivity with ohmmeter.
-Swapped out the VCAs, 5534s, 5532s, Tl072 and TL074s for no change.  
-I visually verified the resistors from the working board to the almost working board, and haven't found a problem yet.
-Tested the new control switch board with the working SSL board and it works good.
-Swapping the input channel cables keeps the problem the same, swapping the output cables moves the problem to the other channel.

What I haven't done is:
-Verify capacitor values
-Swap out the sidechain VCA

So this is all I can think of in troubleshooting today, does
anyone have suggestions?

thanks!
-Jay
Title: SSL HELP THREAD!!!
Post by: moogfrotee on January 23, 2006, 04:21:45 PM
sorry to intemit.
I just realised something that I wan´t to share.

I built two SSL from audio kitchen PCB´s so far, that was my first experience and I´m still learning.

The second SSL has a problem when release is switched to auto position:
distortion, but not bad sounding rather very detailed and schmothh.
The more compression the more distortion.

I just left it this way because I´m to much a beginner to realy understand this to the detail.

Two days ago I found out why this happens in auto mode: because I configured the switch to 6 positions instead of 5.

I have no lettering on the SSL so far thats why it never attracted my attention.

I have no idea whats happening when the switch is like that, but it sounds cool. Could it harm the comp? thats acctualy the only concern I have ,sometimes mh...not realy because apart from that it´s working fine!

When it´s not bad for the comp, I will leave it that way

max
Title: SSL HELP THREAD!!!
Post by: BR on January 23, 2006, 05:51:21 PM
Hey indogom,
I experienced the same problem with mine and it was a shorted out cap on the output.  One of those .1p caps.  (thanks Steve for finding that)
Check them with a dmm,  and see if any has gone bad or is bad..
 
Gil
Title: SSL HELP THREAD!!!
Post by: indigom on January 23, 2006, 07:19:55 PM
Quote from: "BR"
Hey indogom,
I experienced the same problem with mine and it was a shorted out cap on the output.  One of those .1p caps.  (thanks Steve for finding that)
Check them with a dmm,  and see if any has gone bad or is bad..
 
Gil


So given this excellent advice from Gil and Steve, I went right for the problem.   It was one leg of a 100pF cap in the Output Section which was soldered against something that it shouldn't have been.  A little de-soldering braid on it and it's fixed.    The thing sounds great now, nice and open with appropriate levels on both channels.
 :sam:   beers for everyone!

cheers!
-Jay
Title: SSL HELP THREAD!!!
Post by: Nadege on January 24, 2006, 10:39:51 AM
Hi everybody.

Now that my ssl clone has the rigth tension (thanks Jakob) I've got another problem.

The unit is working (compressing, meter ok, power LED ok, audio passing thru the unit, ...) but..  :evil:

- I've got a very loud Hum, on both side at the same level... I read what was said in the thread and try some stuff like moving the transformer out of the box, checking all my componant value, looking for shorts, made some continuity test between the main PCB and the control PCB, but nothing change. Also checked my XLR connection to the PCB

-The Hum gets louder with the make-up pot and don't disapear with the bypass switch. The control are active on the hum i.e. The compression is active on the hum.

-With the Make up pot on "0" both side have the same level, but when the make up increase, only the rigth side increase in level, the left one doesn't change....


I suspect a short in the sidechain circuit, is it possible that this could make this hum and wrong level compensation balance ???

Thanks for your help. :cry:
Title: SSL HELP THREAD!!!
Post by: Greg on January 24, 2006, 11:05:07 AM
Problems in the sidechain would effect both channels the same. So if something is screwy in only one channel, I would look outside the sidechain first.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 24, 2006, 12:26:25 PM
Ok, I checked the sidechain, all is seems to be alrigth there. Where should I look????
Title: SSL HELP THREAD!!!
Post by: JerryPbury on January 24, 2006, 04:08:09 PM
I have a Pair of the DBX 202's. Does anyone have a Mouser or Digikey part # for sockets for the PCB? I would prefer not to drill out the current holes to size in the pcb and soldering the 202's in. Also if anyone has a spare 2150 for the side chain let me know a price.

Anyone?

Thanks,

Jerry
Title: SSL HELP THREAD!!!
Post by: gyraf on January 25, 2006, 02:18:00 AM
The 202's should be soldered in - they're too heavy to mount reliably in sockets.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on January 26, 2006, 01:15:31 AM
OK,
I have 2 board sets from the Chef just about fully loaded & almost ready to mount in the chassis but have a few questions.

1 - There are 10 100p caps on the board but only 9 listed in all the parts lists I've seen. WHY?

2 - I'm using one of these on the insert of the subgroups unbalanced
& the other one on the master out balanced ...
which would be better for either:

0db (27k - unity) or +6 db (15k)
Which do you guys find MOST useful?????????

3 - I have "ALL" the different VCA's and wonder which are considered the "BEST"? Like I said - 1 for drums & 1 for Master (final) out.

4 - Are there any problems or new changes on the Chef's circuit board I should know about?

5 - Do the switches have to be mounted on the PCB any certain way?

5 - Is the "NEW" sidechain a must have or does this thing kick ass without it? I guess I'm asking should I leave space to add it in later?


I did try reading thru the forum to find answers but didn't find what I needed.

Thank you Mr. Green
Title: SSL HELP THREAD!!!
Post by: gyraf on January 26, 2006, 02:36:41 AM
Quote
1 - There are 10 100p caps on the board but only 9 listed in all the parts lists I've seen. WHY?


Counting error? Mount the board as silk-screened, and you'll be fine.

Quote
2 - I'm using one of these on the insert of the subgroups unbalanced
& the other one on the master out balanced ...
which would be better for either:

0db (27k - unity) or +6 db (15k)
Which do you guys find MOST useful?????????


use 27K - you have extra makeup gain to work with.

Quote

3 - I have "ALL" the different VCA's and wonder which are considered the "BEST"? Like I said - 1 for drums & 1 for Master (final) out.


THAT2181LB

Quote
4 - Are there any problems or new changes on the Chef's circuit board I should know about?


No.

Quote
5 - Do the switches have to be mounted on the PCB any certain way?


No, not as far as I can see. We've never had the problem here anyway - and I'm sure we would if it was possible to mis-mount those.

Quote
5 - Is the "NEW" sidechain a must have or does this thing kick ass without it? I guess I'm asking should I leave space to add it in later?


Imo, it's a gadget that might be usefull for some things, less for others, but the unit is very, very good as-is. I've never really liked the filtered-sidechain compression - but I rarely do modern bass-and-drum-heavy mixes anyway.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on January 26, 2006, 03:11:39 AM
Jacob,
Thank you very much.  :thumb:

One of my final concerns is if I choose the 2181, I'll have to make some changes to make them work & it seems there are a few different opinions about this. Is there a simple bread & butter method to the changes?

 :idea: If the side chain is the only affected area with the 218x's, couldn't I use a 215x in the detector circuit only *AND* leave all the components stock or does the circuit still need to be changed? It seems like the most efficient way to use the different VCA's (for their voicing/character - audio path) without having to change the other stuff (ratio's, etc...).

Am I on track here?

BTW, I'm soldering this thing right now & should have it done by morning...long night ahead, can't wait :thumb: :green:
Title: SSL HELP THREAD!!!
Post by: gyraf on January 26, 2006, 03:21:16 AM
THAT2181LB for all three VCA's seems to work just fine..
Title: SSL HELP THREAD!!!
Post by: khstudio on January 26, 2006, 03:37:25 AM
I'm confussed... I thought the 218x messed with the ratio's?

Also, is there any reason you recommend the 2181 over the 2180 (pre-trimmed)?

I have 2150, 2151, 2180 (a,b,c), 2181(a,b,c).

I was thinking, for the drums using 2151's & Master bus the 2180's.
Title: SSL HELP THREAD!!!
Post by: gyraf on January 26, 2006, 04:14:27 AM
First build one, listen to it, and decide from there..
Title: SSL HELP THREAD!!!
Post by: Greg on January 26, 2006, 08:20:23 AM
Just make sure to use sockets so you can swap them out easily.

Regarding the question about the "new" sidechain, I just wanted to state here that the board I designed isn't a "new" sidechain. It's simply a buffered high pass filter inserted into the existing sidechain. I've had questions about this in past and some people are under the impression that my board is more than a filter. And I agree with Jakob, GSSL is a great unit as is, but when working with bass heavy material, I find the GSSL can get a bit aggressive and start pumping on the low end. The sidechain filter helps out with this.

I think it's useful... and an easy addition.
Title: SSL HELP THREAD!!!
Post by: mathflan on January 26, 2006, 01:09:14 PM
HI everybody!

I'd like to know which Vu-meter I have to take for the SSL and Where I can get it in EUROPE or Worldwide.

thanks for help


 :grin:
Title: SSL HELP THREAD!!!
Post by: gyraf on January 26, 2006, 01:25:53 PM
Hi mathflan,

Do a search. It has been discussed over and over again.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mathflan on January 26, 2006, 01:47:10 PM
ok sorry

i don't find my answer on the META thread of the ssl.. :sad:
I'll take a look on the 80 pages of the SSL :shock:

thanks
Title: SSL HELP THREAD!!!
Post by: mathflan on January 26, 2006, 02:31:31 PM
ok my answer is on the first page, Sorry :oops:
Title: SSL HELP THREAD!!!
Post by: Nadege on January 27, 2006, 05:57:50 AM
HI,

I was wondering wich 15K I've got to upgrade to 27K to have unity gain? Couldn't found an answer on the thread.

Just tell me wich rsesistor regarding Gyraf's schematics of the compressor

Thanks a lot
Title: SSL HELP THREAD!!!
Post by: Greg on January 27, 2006, 08:22:31 AM
It's the one right before the channel VCAs.
Title: SSL HELP THREAD!!!
Post by: Nadege on January 27, 2006, 08:54:39 AM
Thanks Greg
Title: SSL HELP THREAD!!!
Post by: mathflan on January 27, 2006, 01:26:26 PM
I found Switches For Bypass , Looks like Real SSL.


Check : its on the online shop REICHELT

SWITCH+LED (http://www.reichelt.de/inhalt.html?SID=14Q9ZNqdS4AQ4AACb4gEY025202cf8d2a291242d05602a7956135;ACTION=7;LASTACTION=6;SORT=artikel.artnr;GRUPPE=C228;GRUPPEA=C22;WG=0;ARTIKEL=A01-01R;START=0;END=16;FAQSEARCH=Printstecker%2C%20Einzelstecker%2C%20gerade%2C%2010-polig;FAQTHEME=-1;FAQSEARCHTYPE=0;STATIC=0;FC=755;PROVID=0;TITEL=0;DATASHEETSEARCH=A01-01R;FOLDER=C200;FILE=A01%2523APM.pdf;DOWNLOADTYP=1;DATASHEETAUTO=;OPEN=1)
Title: SSL HELP THREAD!!!
Post by: mathflan on January 27, 2006, 01:30:50 PM
New link In english :

http://www.apem.fr/pdf/uk/section_g/01-Series%20A01_A1-A.pdf

the switches are From APEM

www.apem.com
Title: SSL HELP THREAD!!!
Post by: Nadege on January 28, 2006, 03:53:59 AM
Hi,

I definitly have huge trouble achieving my GSSL compressor. I've build two unit and both of them have problem.

On the first one : Audio is passing thru, compression is working, voltage are OK but I've got a huge hum.

On the second one : Audio is passing thru, compression doesn't works (pot are inactive), no hum, but I've got something like DC going out of the unit. At first, The make up gain was working, but after some check it doesn't work anymore. I swapped the IC from one unit to another but now It's still not working and I've got a huge distortion....

In both case I checked the component value, their are the same on both board, Looked for short, couldn't find anything, made some continuity test, but all seems alright...

When I press the IC on their socket, something ??? but what ???? is changing, the strange "DC like" sound of my second unit is changing, but no amelioration at all.

Did I missed something???

O my god I'm so sad, I don't no what to do anymore....
Title: SSL HELP THREAD!!!
Post by: khstudio on January 29, 2006, 01:26:32 AM
Please help.

OK, just got my GSSL up & running... it's pretty killer BUT - Why is the bypass level so much lower than the original input? It doesn't make for much of a comparison.
 :?
Title: SSL HELP THREAD!!!
Post by: Nadege on January 29, 2006, 01:21:50 PM
Hello,

try some change with the IC, It seems that something is wrong with my second clone in the TL072/74 region because when I replace them with others, the way this strange "DC like" sound is comming change also. It is still ther and really loud but the way it's comming when I powered up the unit is different from one IC to another...

Any suggestion?

And I still have a giant hum on the first unit...
Title: SSL HELP THREAD!!!
Post by: fucanay on January 31, 2006, 06:55:23 PM
Hello, I think this is my first post on this topic. I have a couple of Gustavs board that I'm building. One I'm building for me to use with unbalanced inserts on my console and the other I'm building for a friend to use on the balanced inserts on his console. His seems like a standard build, but I'm not so sure about mine. It seems that there are issues with running unbalanced with this unit. And since I never plan to use this during tracking, I thought it would be a good idea to avoid those problems from the start.

So how do I go about solving this? I've seen the info in the 15k resistor being changed to 27k, but is that all I need to do? Should I be using TS jacks instead of TRS? If so how would I hook them up?

I'm sure this is pretty basic, but I have yet to actually finish anything yet. I've got a dual green and two GSSLs being built at the same time. I'm getting way closer to being finished with everything, but these little details are slowing me down big time and I also don't want to be ordering the wrong parts.

Also, one more thing. Would it be ok to use an IDE ribbon cable cut down for the control panel PCB to main PCB cable? I think it would look so much better than a bunch of loose cables.

Thanks,

Matt
Title: SSL HELP THREAD!!!
Post by: kryckmeister on February 01, 2006, 04:03:52 AM
I HAVE been looking around, so don't tell me I'm lazy, just stupid if I missed something obvious  :cool: .

With my SSL the meter drops all the way down when moving the threshold past like 12 o' clock. I'm definetly a n00b at this, but I passed it on to someone who's capable of dealing with this but I thought it might be decent to try and find the solution to the problem.
Any idea of what it might be or where to look?

The n00b salutes you!
Title: SSL HELP THREAD!!!
Post by: mathflan on February 01, 2006, 01:04:07 PM
I'd like to know if I can Put a Toroid Transformer 220V->2*15 with 30VA??

30VA is it too much??
Title: SSL HELP THREAD!!!
Post by: Greg on February 01, 2006, 01:08:58 PM
30VA is fine. The compressor will only use what it needs. You'll just plenty of spare "juice" for LEDs and lamps if you want.
Title: SSL HELP THREAD!!!
Post by: mathflan on February 01, 2006, 01:58:29 PM
Ok, thanks greg :wink:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 01, 2006, 01:59:08 PM
Quote from: "fucanay"

Would it be ok to use an IDE ribbon cable cut down for the control panel PCB to main PCB cable? I think it would look so much better than a bunch of loose cables.


I would like to know this too.

Quote

So how do I go about solving this? I've seen the info in the 15k resistor being changed to 27k, but is that all I need to do? Should I be using TS jacks instead of TRS? If so how would I hook them up?


Those resistors have to do with volume only.
Title: SSL HELP THREAD!!!
Post by: Greg on February 01, 2006, 03:00:43 PM
Yea some people around here have used IDE ribbon cables. It'll work fine. Regarding the 15K/27K, it just changes gain. With the 15K, the unit has +6dB gain, with the 27K, it runs at unity.
Title: SSL HELP THREAD!!!
Post by: fucanay on February 01, 2006, 03:13:38 PM
Quote from: "Greg"
Yea some people around here have used IDE ribbon cables. It'll work fine. Regarding the 15K/27K, it just changes gain. With the 15K, the unit has +6dB gain, with the 27K, it runs at unity.


So would it be good to change them both to the 27k resistors? I stuffed the boards with the 15k because that's what is shown on the boards, so I'll need to remove them if I have to do this.

Thanks for the affirmation on the ide cable, I think that should work pretty good to keep things neat.

Also, what about using TS jacks on the one that will always be used on unbalanced inserts? Is it necessary or will an unbalanced cable into a TRS jack work without issues?

Thanks,

Matt
Title: SSL HELP THREAD!!!
Post by: Greg on February 01, 2006, 03:23:35 PM
Yes, replace the 15K with the 27K. That's what I used in mine. I want unity from comps most of the time.
Title: SSL HELP THREAD!!!
Post by: gyraf on February 02, 2006, 03:33:33 AM
But if you plan to use unbalanced-out, you need the +6dB (i.e. 15K resistors) to acheive unity gain in bypass..
Title: SSL HELP THREAD!!!
Post by: mathflan on February 02, 2006, 12:00:54 PM
DO you know if this meter is appropriate with the SSL??

(https://www.conrad.fr/wcsstore/ConradImages/PRODUITS/959481_p_g.jpg)

I can have This meter with 1ma.


http://www2.produktinfo.conrad.com/datenblaetter/125000-149999/134945-da-01-de-Einbauinstrument.pdf

thanks
Title: SSL HELP THREAD!!!
Post by: fucanay on February 02, 2006, 12:08:38 PM
Quote from: "gyraf"
But if you plan to use unbalanced-out, you need the +6dB (i.e. 15K resistors) to acheive unity gain in bypass.


This is all pretty confusing to me. I guess it's that I'm pretty new to all of this analog stuff. I was using outboard preamps straight into an interface and mixing in Logic Pro before. But now I have a large console that I want to use and need to make my DIY gear to work with it. I have 8 busses and 32 channels with unbalanced inserts that I plan to hook up to a patchbay with Y cables to patch in the GSSL and in the future a couple of  G1176s.

I think I need a good tutorial on signal routing and gain staging.  :?

Matt
Title: SSL HELP THREAD!!!
Post by: gyraf on February 02, 2006, 12:15:04 PM
Quote
I can have This meter with 1ma.


A 1mA version would do fine. ANY 1mA version would do fine.

But you need to check yourself if it will fit your front panel.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mathflan on February 02, 2006, 12:30:28 PM
thanks gyraf for the meter  :grin:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 03, 2006, 06:34:05 AM
Meter lamp Help

I know very little about how to use ohms law to find a dropping resistors value - could someone help me.

#1 Is it safe to use the secondarys off the power transformer?
   (30v or even one side/half - 15v)

#2 I have (24volt / 3 watt) bulbs I thought would be close but don't know how to do the math... & would like to learn.

(I need the value & wattage.)

#3 How do you guys do it?  I tried a single LED but didn't like it.

Kevin
Title: SSL HELP THREAD!!!
Post by: khstudio on February 03, 2006, 07:13:15 PM
Nobody?

 :mad:
Title: SSL HELP THREAD!!!
Post by: CJ on February 03, 2006, 07:41:41 PM
safe to use sec.

figure out current you want thru lamp first.

3 watts (man, that might be too much heat, keep it away from meter plastic)
you can increase R to drop heat and stll have good light.

watts is volts times amps,

so a 24 volt bulb means we use 24 for our calculation,

to get amps, we use watts and volts,


3/24 = 0.125 amps

ok, how many volts from transformer?

we need more than 15, that's for dang sure,

so use your 30 volt winding.

30 volts, series circuit, current the same everywhere,

24 volt lamp, we have 6 extra volts to kill. this is the resistors drop.
but how many ohms?

easy:

6/0.125 = 48 ohms on this side of the Atlantic.

done!
no. :sad:

watts needed, and we double our answer for saftey and low stress

watts is volts times amps, and so we can simply use 6 times 0.125
for 0.75 watts, double that and you ask the man for a 2 watter at 48 ohms.
47 is standard, 51 is standard, so get the 51 for less current and less heat.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 03, 2006, 08:09:55 PM
CJ your the man. :thumb:

Do you think it would be better to use a 6 volt bulb off one side = 15 volt?
Title: SSL HELP THREAD!!!
Post by: Greg on February 04, 2006, 11:59:22 AM
Assuming the same power, the higher the voltage bulb the less current it will draw, so I guess in general the higher voltage bulb is the way to go. I usually try to use 24V bulbs.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 05, 2006, 06:11:06 PM
I was reading the post on the ratio adjustment & need some help. I built 2 units - 1 with 2151's & the other with 2180 - less trimmers (2151 in side chain) & both seem to have the negative 10:1 ratio going on. I tried the 100k to 120k change, it did work but I'm not sure I liked what it did to the sound of the unit.
I'm confused because I thought that with the 215x series everything would/should fall into place & from testing my own it seems they both have this problem.

Has anyone compared the GSSL to a real SSL 384FX (? model)

I really like these units & just want to be confident with my builds.

The first one I built (without the ratio mods) with the 2151 all around (Poly caps) sounds great on a parallel drum buss & I'm afraid to change it... unless I install a switch (for the ratios) to go back & forth.

The 2nd has Metal films, 2180?s, 2151 sidechain. I was thinking of adding the trimmers like the SMART C1 does to the 2180?s? maybe they?re too clean or the circuit isn?t set up for them correctly.

1 more thing? I added a resistor to the + leg of the threshold (with a switch so I could compare) & it worked but when I set it to a similar level (switch on/off) it wasn?t the same. It seemed to affect the ?attitude? of the compression more than it should? is there something else happening when adding this resistor? I think it might sound better stock even with the limited range.

Kevin
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on February 05, 2006, 10:49:03 PM
Just finished my fourth SSL - works great.  Thanks to everyone for the help.

I'm sure this has been covered, but I can't seem to find the info.  I've noticed all the SSL's have a gain boost of around 4-6 dB when simply patched in - bypassed or not.  How do I get rid of this, so that the unit is passing unity gain when bypassed or engaged?

Thanks.
Siegfried
Title: SSL HELP THREAD!!!
Post by: khstudio on February 06, 2006, 12:20:20 AM
Quote from: "Siegfried Meier"
Just finished my fourth SSL - works great.  Thanks to everyone for the help.

I'm sure this has been covered, but I can't seem to find the info.  I've noticed all the SSL's have a gain boost of around 4-6 dB when simply patched in - bypassed or not.  How do I get rid of this, so that the unit is passing unity gain when bypassed or engaged?

Thanks.
Siegfried


Change the two 15k resistors (just outside the main VCA's) to 27k & it will defeat the 6db boost your getting.
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on February 06, 2006, 11:13:21 AM
Thanks for the info.  Could you point out in a pic exactly which ones to replace?

Thanks.
Siegfried
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on February 07, 2006, 04:27:51 PM
Just curious - are these the exact resistors you're recommending be changed in order to get rid of the 6 dB boost?  Where in the chain is it dropping the level down?  On the output?  

Thanks!

(http://www.siegfriedmeier.com/mysql-clients/15k%20Resistors.jpg)
Title: SSL HELP THREAD!!!
Post by: khstudio on February 07, 2006, 11:31:25 PM
I'm sorry I've been away for a few days & don't know why nobody helped you by now but YES, they are right!
Title: SSL HELP THREAD!!!
Post by: Siegfried Meier on February 07, 2006, 11:55:32 PM
Haha.  No worries.  I guess since they figured you replied to me first, you'd do it again.

Thanks so much!

Siegfried
Title: SSL HELP THREAD!!!
Post by: gyraf on February 08, 2006, 04:04:47 AM
Quote from: "Siegfried Meier"
Where in the chain is it dropping the level down?  On the output?  


Naa - look at the schematic again. The 15K resistors are voltage-to-current converters at the input of the (current-controlled, current-input) VCA's.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 08, 2006, 09:38:13 AM
Hi,

I have a few more questions before I buy all the resistors and capacitors and this kind of things. Can you give me some info on your personal changes or if you replaced something or added for getting your ratio or threshold or whatever adjustments needed for your G-SSL. I will use the 2181LB VCAs. This will help me a lot so I can buy the right things from the start.

1.) Can someone explain the unity (-/+ 6dB) thing with G-SSL? Do I need to change anything here? Some are complaining about it so I thought I need some more knowledge here.

2.) I bought the Farnell meters which Gyraf recommended (METER, EDGE  100uA) Do I need to put some resistors in the chain to get the 10dB meter scale working properly?

3.) What is the optimum power supply for the G-SSL if I put some extra LEDs or maybe power and bypass square knobs with light bulbs inside like in the original design? Toroid 15V or more power, what is the optimum here?

Gyraf, Greg, anyone please? :idea:
Title: SSL HELP THREAD!!!
Post by: Greg on February 08, 2006, 09:48:07 AM
Regarding the ratios, you'll have to do it yourself... that's it I already explained that to you.

1) If you want unity/balanced, use 27K resistors in place of the 15K... circled a few posts up.

2) Take a look at the schematic and you will see that for a 100uA meter, you need to shunt the meter with a 330R (IIRC). If you want to change the scale further, change the 2K meter series resistor. But this is done after the unit is built. Just use the 2K and see where this gets you.

3) It's not really the voltage to worry about. It's the current the lamps/LEDs will draw and the VA rating on the power tranny. A 30VA power tranny should be plenty of juice, but if you need DC I'd pull it pre-regulation as to not stress the regulators. You'll also need the appropriote series resistor.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 08, 2006, 10:10:15 AM
Thank you Greg.

I have one more question regarding THRUST filter. I am very bad at reading schematics. Does anyone of you have a PDF list of parts needed for this filter?
Title: SSL HELP THREAD!!!
Post by: Purusha on February 08, 2006, 06:43:52 PM
Hi everyone,

I have more questions:

1. Is the make-up gain bypassed by default Gyraf schematics when bypass switch is on or I have to make some additional modification to bypass it when bypass is on?

2. Are IC sockets necessary or can I just solder all those semiconductors directly to the PCB? I would like to get the best possible contact. Some believe there is a loss in sound quality if IC sockets are used. Anyone tested this yet?


I am a newbie here so please be patient with me  :oops:    :grin:
Title: SSL HELP THREAD!!!
Post by: Greg on February 08, 2006, 07:30:42 PM
1. On Gyraf's PCB layout PDFs, he shows how to hook up the bypass switch to defeat make-up in bypass mode.

2. Use sockets... you'll thank me later if you have any problems with the build. Sockets make contact just fine for me...  :wink:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 09, 2006, 03:43:15 AM
Thanks again Greg  :thumb:

I may also take out all the sockets later, they don't cost much anyway  :idea:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 09, 2006, 06:06:15 AM
I've been researching & testing my GSSL comps for days now to get a grip on the sounds of the different VCA's & the ratio's.

Am I right to come to the conclusion that the CV of 50mv to 6mv isn't really a problem & that the ratio problem is about the same for both. I read the THAT's data sheets on upgrading to 218x from 215x & it shows & says NOTHING about compensating for the CV difference. The whole time I've been jammed up about this, thinking that the CV change would make the newer VCA's compress more or not the right way bacause of this.


Also, I have one unit with all 2151's & one with 2180LA's. I tried using each in the sidechain of the one fitted with the 2180 & it is a lot more trasparent & also reacted totaly different to frequncy & seemed to be much faster & smoother with the 2180 in the sidechain (less 47R when installed)... even in bypass, which seemed strange.


1 more thing. Is there any way to speed up the seond half of the AUTO release... when hit hard it takes a very long time to open back up, just a hair too long for me even on moderate threshold settings?

Kevin
Title: SSL HELP THREAD!!!
Post by: gyraf on February 09, 2006, 06:37:42 AM
Quote
Is there any way to speed up the seond half of the AUTO release... when hit hard it takes a very long time to open back up, just a hair too long


The auto release is really just two added time-constants, a fast one for rare transients, and a slow one for frequent transients. There is a 0.47u tantalum cap that runs the fast part of the timing, and a 6u8 that runs the slow part. Put in lower value caps to get faster timing, higher values to get slower. Maybe make a 6'th step on your release switch for this.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 09, 2006, 07:03:49 AM
Quote
Maybe make a 6'th step on your release switch for this.


Dude... What a great idea!

 :thumb:  :guinness:  :guinness:  :guinness:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 09, 2006, 07:36:43 AM
Quote
Maybe make a 6'th step on your release switch for this.


I like this idea also. Is it difficult to wire this one properly?
Title: SSL HELP THREAD!!!
Post by: Greg on February 09, 2006, 07:42:03 AM
hey Purusha:
Before attempting modications, Jakob (and myself) always recommend building the unit as is then modify to taste if necessary.  :wink:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 09, 2006, 07:52:38 AM
Jakob,
Can you or anyone more experienced than me help with my other Q's in my last post concerning the VCA - CV - 6 & 50mv?
Title: SSL HELP THREAD!!!
Post by: Purusha on February 09, 2006, 07:59:15 AM
Quote from: "Greg"
hey Purusha:
Before attempting modications, Jakob (and myself) always recommend building the unit as is then modify to taste if necessary.  :wink:


I understand this. But I am building 6 of them for me and my friends and would like to buy as much as possible in one place at once to get the best possible price.
Title: SSL HELP THREAD!!!
Post by: gyraf on February 09, 2006, 09:21:15 AM
Quote from: "khstudio"
Jakob,
Can you or anyone more experienced than me help with my other Q's in my last post concerning the VCA - CV - 6 & 50mv?


Sorry, i haven't run into the VCA problems, so I have no idea..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 09, 2006, 09:40:53 AM
Well, I really shouldn't have said problems... I'll try again.

I just want to learn something. What is the difference between 6mv & 50mv. It has to effect something... What? Is it dynamics, headroom, threshold of the VCA input or CV?
Title: SSL HELP THREAD!!!
Post by: Purusha on February 09, 2006, 09:56:39 AM
I have a dilemma what to buy since I can't get the exact things here in my town.

1. Power supply "2x15V or 2x18V, 4.5VA" written on the schematics but in the part's list it is mentioned 25VA ???

These two are the closest I can get to 25V or above:

- TOROID  2x18V 50VA   19$
- TOROID  2x15V 50VA   13$

3. Regarding the tantalums I can't get any 50VA here. There are the closest ones:
Panasonic
TANT 6,8uF 35V 20% R2,54,
TANT 0,47uF 35V 20% R2,54
Will this be OK or should I get something else?

4. About 50K linear potentiometers I can find only 47K. Is this OK?

5. Hi pass rotary switch 2x8 can't be found also, only 2x6. I guess I can just forget about adding the two positions for THRUST to Stephen's filter. Any suggestions?
Title: SSL HELP THREAD!!!
Post by: Greg on February 09, 2006, 11:53:15 AM
1. Get the 2x15V 50VA. You can always go higher with the VA rating. You'll just have ALOT a spare juice for LEDs and lamps.

2. Where's question 2?

3. Yes, 35V tants are fine. The highest voltage in the GSSL is 15V.

4. Isn't 50K a common value? I'd recommend trying to find it.

5. The Steffen high pass only really needs one pole, not two. If the THRUST only needs 1 pole as well, then get a 1x12 switch and move the stop to the eight position. If you need two poles, you'll have to find one of those dual deck switches.

PS, not to be an ass, but please try and be more patient when waiting for responses. I work at an Electrical Engineering company during the day and sometimes I do not have the time to answer questions over and over again.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 09, 2006, 12:58:59 PM
Quote
PS, not to be an ass, but please try and be more patient when waiting for responses. I work at an Electrical Engineering company during the day and sometimes I do have the time to answer questions over and over again.


Yeah, shame on me  :oops:  

I was just ordering some things and the guy at the shop was not very patient with me. Sorry for this...

BTW thanks for your help.  :thumb:
Title: SSL HELP THREAD!!!
Post by: TornadoTed on February 09, 2006, 08:18:20 PM
Hi. My first post I believe. I'll come clean I'm an idiot at electronics and don't have a clue how to build one of these things. I'm a sound engineer and soldering multicores is about as adventurous as I get. I have a friend who is building me an SSL clone (he used to be a tech for SSL) and it's my job to get a meter. I have the DIY spirit as long as it's wood, I made a 2u box for it out of maple along with copper foil and I'm having a crack at the 3M Super77 along with reverse laser printing method for labelling it. Where can I get a meter in the UK? specific links would be nice as I haven't a clue! It's a 2 u box and I'm after something about 60x80mm (HxW) that is front mounting. Any help appreciated. Ted
Title: SSL HELP THREAD!!!
Post by: BR on February 09, 2006, 10:53:39 PM
Hey there TornadoTed,
welcome to groupdiy.
You will find that most of us (maybe I should just speak for myself) are here learning from the masters at this, who gladly take time from their busy lives to help us unexperienced however enthusiastic diyers.

My first tip for you is to look at the Meta's on top of the page.  Overthere you will find pretty much all the info on the SSL Clone.  But since this is your first post.... here is where you can get some very nice meters:
http://www.sifam.com/presentor.lasso
The presentor series is the one that I've been using on my last few clones and they are very accurate and reliable.
The Director series is meter on the SSL consoles.  Be prepared to spend some good money for those.
I believe that I payed US$65 for my meter, but that included shipping.
Just order any of the ones you like with the sensitivity of 0-1ma.
but I'm sure more people are going to give you other ideas.

take care
Gil
Title: SSL HELP THREAD!!!
Post by: gyraf on February 10, 2006, 03:32:31 AM
Thanks, Greg!

A small comment:

Quote
4. About 50K linear potentiometers I can find only 47K. Is this OK?


Yes, 47K is the name in Europe for a 50K pot - we use the E3-series not only for resistors, but also for pots.
The 50K's are used as simple voltage dividers in the Gssl, so really anything from 22k to 100k would probably work.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 10, 2006, 05:24:57 AM
Jacob,
Would it be ok to run a 5volt 20ma Blue led (only one by itself) off the LED pads on the circuit board, maybe dropping the 1k a little?

#2, Would it be safe to add a switch to change the ratio's from stock - (inverting @ 10:1) to the corrected to match the front panel settings. I'm using the 100k to 127k mod recommended by Steffen which seems to work very good but on the drums I think I preffer the higher ratio's. Mine reads about 3:1, 6:1 & inf:1 stock (100k). I'm concerned about running a wire from this resistor to a switch & back because its in the sidechain signal path & from what I read on the THAT's website. They say to watch out because stray signal getting into the CV can degrade performance & not track as well because they're so sensitive.


Also, does anybody know how the 50mv to 6mv Control Voltage affects the VCA's? I've got 2 units set up differently & they're both kicking ass... just want to learn whats happening here.

Thanks
Kevin
Title: SSL HELP THREAD!!!
Post by: TornadoTed on February 10, 2006, 06:45:58 AM
I've done a bit of searching around and got totally confused. I've found these on the RS components website, you just need to copy the numbers below into the 'Find products' box at the top of the page.

http://rswww.com/cgi-bin/bv/rswww/home.do?cacheID=ukie


Meter - 1968402
Bezel - 1968682
6 way switch (attack and release) - 665196
3 way switch (ratio) - 665219
Copper foil sheets (the enclosure is wood so I've been told I need copper foil to stop RF and such like - 680959

I already have an account with them so sourcing from them is easier than sourcing elsewhjere if these are suitable.

I'd be so grateful if somebody could check them out for me and let me know if they are what I need for the SSL clone in a 2u case. A friend is building the electronics for me but has left me to get these few bits and pieces. I built the case out of maple, looks stunning. Boy I feel out of my depth  :roll:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 11, 2006, 12:26:17 PM
By Greg
Quote
5. The Steffen high pass only really needs one pole, not two. If the THRUST only needs 1 pole as well, then get a 1x12 switch and move the stop to the eight position. If you need two poles, you'll have to find one of those dual deck switches.


Does any one of you know if thrust filter needs 1 pole or 2? What kind of rotary switch would accommodate Stephen's and thrust filter? I could not find 2x8 so far. Would 1x12 be OK?

I would like to get my last parts together and start soldering  :grin:  just few things missing  :thumb:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 14, 2006, 04:22:18 AM
I am still trying to findout what rotary switch to use for two hi pass filters. Anyone?
Title: SSL HELP THREAD!!!
Post by: Greg on February 14, 2006, 08:06:26 AM
Post a schematic for the thrust filter... and I can explain to you how many poles you need.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 14, 2006, 08:29:00 AM
Hey Greg,

have you checked at Western Union Bank for the money I sent?

I need to know this one asap so I can add your full middle name if needed in the WU bank tomorrow. What does your W. stand for? If you have this middle name W. in your personal documents than you better let me know it so I can tell this in WU bank otherwise they might not give you the money in USA.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 14, 2006, 08:29:51 AM
For the thrust filter: http://www.groupdiy.com/index.php?topic=12749&start=0&postdays=0&postorder=asc&highlight=thrust

(http://home.hetnet.nl/~chickennerdpig/FILES/API/sc-circ_thrst_01.jpg)
Title: SSL HELP THREAD!!!
Post by: Greg on February 14, 2006, 08:43:49 AM
You only need one pole... ie one switch.

If you needed two things to switch simultaneously, then you'd need two poles.

Also, if you read the very first post in the thread you linked me, it answers your question. He talks about using a 1x12 switch to combine the high pass and the thrust...  :thumb:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 14, 2006, 08:48:56 AM
Quote from: "Greg"

Also, if you read the very first post in the thread you linked me, it answers your question. He talks about using a 1x12 switch to combine the high pass and the thrust...  :thumb:


You are right. Thanks.

What about the bank transfer?
Title: SSL HELP THREAD!!!
Post by: Purusha on February 14, 2006, 09:15:48 AM
What is this part? I can't find it on the SSL part's list.

(http://users.volja.net/purusha/GSSL_part.jpg)
Title: SSL HELP THREAD!!!
Post by: kruz on February 14, 2006, 09:28:58 AM
that's a diode bridge
W04
Title: SSL HELP THREAD!!!
Post by: Purusha on February 14, 2006, 09:51:35 AM
Thanks  :thumb:
Title: SSL HELP THREAD!!!
Post by: nwsoundman on February 14, 2006, 10:23:33 PM
I am wondering if anyone who uses the Modultec 541-ME-DMA-001 meter from Mouser has verified the meter track GR properly?

I bought two of the and they both behave the same in my GSSL. The problem is that when there is 6 dB of reduction happening the meter only presents 2 dB. I measure just over 600 mvdc on the meter driver IC and at the meter itself. If I remove the meter sensitivity resistor and replace it with a jumper the meter presents a bit over 4 dB of GR.

I think the problem is that the meter resistance (internal) is 2300 ohms according to the data sheet.

I have corrected the ratios and the box sounds good. I just need to correct the meter issue. Can I just leave the jumper in place and change the gain of the meter amp to maybe .2 or .3 volts / db instead of the.1?

Also I have found a way to light these meters. I drilled a hole in the bottom of the meter case and inserted a blue LED powered from the control PCB. If you line the top inside the meter case wih foil the LED has no hot spots and very even distribution.

Thanks for any ideas on the GR tracking.

Kirk
Title: SSL HELP THREAD!!!
Post by: khstudio on February 15, 2006, 08:49:19 AM
I did the same thing with the LED. One is the newer VCA's (218x's) = Blue LED & the other one is the older/dirtier VCA's(215x's) = Red LED.

I'm still a little concerned about the difference in voltage/current from the stock LED connected to that pad. It seems the Blue LEDs I'm using want 5 volts :shock: & more amps. I wonder if it will create any problems :?:
I asked a few weeks ago & don't remember getting an answer. O well, I'll be posting some pics soon... they turned out great!

This site & the people here are KILLER! :thumb:
Title: SSL HELP THREAD!!!
Post by: gyraf on February 15, 2006, 10:50:46 AM
If you mis-track, then use a trimmer pot instead of the 2K meter resistor..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 15, 2006, 10:51:13 AM
Roger,
I tried the 120k mix res. you talked about & it didn't seem to fix the ratio's or have much of an effect on the performance. Changing the 100k to 120k worked very well. I also liked all three being the same = 2180's... I tried the 2151 for just the sidchain & although it was cool, the 2180 seemed to track better & clearer. My other unit has all 2151's & has its own thing. Do you think it would be safe to run a wire from that 100k to a switch on the front & back to make it either 100k or 120k? I like the effects (ratio) of both, especially on drums.

Thanks,
Kevin
Title: SSL HELP THREAD!!!
Post by: nwsoundman on February 15, 2006, 11:00:39 AM
Gyraf,

I installed a 5K trimmer already. I am (was) using a 1K meter resistor for a 10db FSD. If I up the value the meter drops, if I remove the resistor or trimmer all together I can get the meter to show me about 4db of reduction when it should show 6 db.

If I measure 600mvdc at the meter shouldn't it present about 6 db of reduction? I verfified that I do have 6 db of reduction by measureing the input voltage vs the output voltage.

Strange.

Kirk
Title: SSL HELP THREAD!!!
Post by: gyraf on February 15, 2006, 11:20:31 AM
Quote
6 db of reduction by measureing the input voltage vs the output voltage.


Counting in the makeup gain?

You should have something like 2V at TL074pin8 (meter drive) when gain-reducing 20dB

Your meter may need a higher voltage (to drive 1mA through the coil) than the 2V that the circuit outputs at 20dB GR.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: nwsoundman on February 15, 2006, 01:18:07 PM
Ok. I am now at the studio so I was able to take a few measurements.

I have inputed a balanced signal and measure .775 volts on the output. My box is set up for unity gain when running balanced. I actually measure a plus .9 db when the conrols are set for no makeup and the threshold fully clockwise (no compression). So since I have .775 on the output I then start reducing gain untill the output measures .062 volts, gain is reduced from 0 db to -20 db. I now see negative 3.080 volts on pin 8 of the 074, negative 2.183 on the meter itself. I have the 1K meter resistor loaded now also. The meer shows about 9 db of reduction.

Thanks for the help,

Kirk
Title: SSL HELP THREAD!!!
Post by: gyraf on February 15, 2006, 01:40:13 PM
20dB under 775mV would be 1/10 - that is 77.5mV, not 62mV

Quote
I have the 1K meter resistor loaded now also.


Does not compute... What do you mean?
Title: SSL HELP THREAD!!!
Post by: nwsoundman on February 15, 2006, 01:52:15 PM
Quote from: "gyraf"
20dB under 775mV would be 1/10 - that is 77.5mV, not 62mV

Quote
I have the 1K meter resistor loaded now also.


Does not compute... What do you mean?


Yes. I accidently looked a the -22 db voltage on my db reference sheet and read -20 as .062 volts.

As for the 1K resistor you ask about. That is the meter sensitivity resistor that should be 1k for a 10 db scale on the meter.

Now I am seeing negative 2.8 volts on pin 8 of the 074 when reducing gain -20 db. Should this voltage be positive relative to the center tap on power transformer secondaries?
Title: SSL HELP THREAD!!!
Post by: mathflan on February 15, 2006, 03:53:07 PM
Hi,

I have a question about the disrtotion trimmer.

I use VCA 2181LB with the modifications :

- Remove 68 R.

- Change 1M ohm resistor to 220 K.

I keep 10 K but, apparently, I have to change it with a jumper, I'm not sure...

As I have to Keep this distortion trimmer with the 2181LB, How I have to set this?
Someone have a method?
Title: SSL HELP THREAD!!!
Post by: khstudio on February 15, 2006, 04:20:18 PM
I found this great link & wanted to share it but have a few questions?

http://groupdiy.silentarts.net/martthie_08/gssl/calibration.html

From member silentarts website:

Quote
CALIBRATION:

Compression ratio adjustment
Replace 100K between pin 8 of TL074 and pin 2 of TL072 with 120K for correct compression ratio behaviour (2:1 / 4:1 / 10:1). I found this value experimentally by measuring the ratio's using a method suggested by "the lab" member SSLTech, you can look here: http://www.groupdiy.com/index.php?topic=944 if you would like to read the original thread.


This is great & worked for me as well.:thumb:

Quote
meter adjustment
use 2K resistor for 0-10dB range or 1K resistor for 0-20dB range of gain reduction indication, when using a 1mA meter. I have the meter set up for 0-20dB range, because if you are sqeezing the sh*t out of a drum room track, you can easily peak on 20dB of compression. For more delicate work, you might prefer a smaller range.


OK, this confussed me. I have a 1mA meter & I'm using a 2k resistor... :?
I though the 2k was for 20db. Which one is correct :?:

Quote
modifications for the use of THAT 2181LA VCA in Jakob's "DBX 2150 to DBX202C emulation" circuit
1. remove the 68k resistor from pin 4 to ground.
2. replace the 10k resistor from pin4 to distortion trim pot with a piece of wire (short it out)
3. change the 1M resistor from 50K trim pot to the THD connection of the DBX202C circuit to 680K.


1. OK

2. Why short out where the 10k was... I just pulled mine like I read here was the way to go :?:

3. Why does the 1m get reduced to 680k... I never read that one either? Can someone explain what these changes do :?:  :?:

Thanks,
Kevin
Title: SSL HELP THREAD!!!
Post by: mathflan on February 15, 2006, 04:37:19 PM
For the Replacement of the resistor 1M by a 680 K:

See here

http://www.thatcorp.com/datashts/dn137.pdf

2181LA : Change 1M by 680K
2181LB : Change 1M by 220K
2121LC : change 1M by 130K

I know this page for calibration, but It doesn't talk About Distortion trimmer calibration??
Title: SSL HELP THREAD!!!
Post by: enthalpystudios on February 15, 2006, 05:27:16 PM
I tried searching for asterisk, and star, and some other things, but couldn't quite find what I'm after.....

The places on the board with asterisks (and one with **), are they optional?  and what are the options for?

I'm off board power trannie, so I know which bridge rectifier spot to use.....

I'm using 2181lc's btw.....  seems I need to follow the above instructions for those....

Thanks

billy
Title: SSL HELP THREAD!!!
Post by: nwsoundman on February 15, 2006, 10:11:06 PM
The ** at the 2K resistor located by the 10 pin connector means that when using a 2K your GR meter will have a 0 - 20 db scale. If you install a 1K resistor your meter scale will be 0 - 10 db. This info is on the PCB PDF's.

The * at the 1K's in the channel VCA's was just a note when Jakob was designing.
Title: SSL HELP THREAD!!!
Post by: enthalpystudios on February 15, 2006, 10:51:14 PM
awesome, thanks man!

should be able to finish the insides of this puppy pretty soon, it'll be the first thing for me, so it's time to feel antsy....


I have to tape mud and paint my basement so I can move down there, or I'll never get a single thing done.... all this crap is in my office along with a bunch of instruments computers and CRAP


very soon, obey-wan
Title: SSL HELP THREAD!!!
Post by: Purusha on February 16, 2006, 06:24:55 AM
I have a question regarding the W04 - 1.5A 400V Bridge Rectifier.

I got only 1.5A 250V Bridge Rectifier (B250C) as closest match. Would this be OK or should I get the W04?
Title: SSL HELP THREAD!!!
Post by: gyraf on February 16, 2006, 06:29:20 AM
How high voltage do you have across it?
Title: SSL HELP THREAD!!!
Post by: Purusha on February 16, 2006, 07:15:20 AM
Quote from: "gyraf"
How high voltage do you have across it?


I ordered torid 2x15V 35VA. Is this answering your question?
Title: SSL HELP THREAD!!!
Post by: khstudio on February 16, 2006, 08:36:00 AM
Why short out where the 10k was ?:mad:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 16, 2006, 08:38:47 AM
Hey Greg,

I found 10 places for 100pF monolitic capacitors on the PCB and not 9 like you mentioned in your part's list PDF. Maybe you can add this in META thread.
Title: SSL HELP THREAD!!!
Post by: gyraf on February 16, 2006, 10:13:14 AM
At 2x15V, a 250V bridge rectifier should work really well..  :razz:
Title: SSL HELP THREAD!!!
Post by: Greg on February 16, 2006, 10:36:06 AM
Thanks. I'll just update my parts list from 9 to 10. There is a discrepency, but go with what's on the PCB... it works like a charm !!!
Title: SSL HELP THREAD!!!
Post by: Purusha on February 16, 2006, 02:12:39 PM
Quote from: "gyraf"
At 2x15V, a 250V bridge rectifier should work really well..  :razz:


thanks!  :thumb:

Finishing soldering PCBs for eight G-SSLs  :thumb:  :grin:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 16, 2006, 02:43:21 PM
Roger,
 thanks... I'll check mine out. I just received Greg's boards & I'm going back in  :wink: .

I posted earlier asking a few questions...could you (or anyone) help me out. The link was to silentarts website. It's very cool he put all the info in one spot with instruction & pics but I'm wondering about a few things listed there.


Hey, youyou really think it will effect performance? It seems strange that the 215x series is ok & the 218x not. On the THATs website it doesn't really show much change to the CV when upgrading but I'm open & want to learn so I can do it right.

 :thumb:
Title: SSL HELP THREAD!!!
Post by: roginator on February 16, 2006, 07:32:25 PM
Im Freshman HERE

So many things about GSSL.....

I just got PCBs and Im gonna make 2 GSSL compressors..I got a 6 VCA 202c Modules so I would like to know few things??

What is best VCA to put as SIDECHAIN VCA..THAT , DBX, MODULE VCA?

What is THAT Price 2180 if I want to put it in side chain....?

Should I sell 2x DBX 202c VCA and buy that or old DBX 2150?

D
Title: SSL HELP THREAD!!!
Post by: gyraf on February 17, 2006, 04:22:18 AM
Hi Freshman,

Read through the related posts in the Meta, and all your questions will be answered..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 17, 2006, 04:36:11 AM
I have a question regarding the 100pF to 100nF change above the feedback cap in the VCA section. I will use the THAT 2181LB VCAs. Can someone explain a little if I need to make the change also and what this change does? Thanks.
Title: SSL HELP THREAD!!!
Post by: gyraf on February 17, 2006, 04:41:10 AM
Should be 100n. Not important really.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 17, 2006, 04:57:29 AM
OK. Great that I didn't bought all the 100p for 8 units yet  :grin:
Title: SSL HELP THREAD!!!
Post by: Greg on February 17, 2006, 07:57:48 AM
@ roginator: The question of what VCA is the "best" gets asked a good bit. And this might not be the answer you're looking for, but there really is no "best" VCA. Just as a crappy analogy, it's kind of like asking "what's the best flavor of ice cream." The point I'm trying to make it's subjective. I've only used DBX 202C, DBX 2150, and THAT 2180LB... listed in order by which ones I like best.

A few folks around here have kind of racked their brains trying to determine which VCA to use, but IMO, it's not really worth the trouble.

Put the 202Cs in the signal path and either a 2150 or 2180 in the sidechain and you'll be a happy customer.  :thumb:

Also, as Jakob stated, please take the time to read through the "Help Thread" and read through the META. Most, if not all, of your questions will be answered.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 17, 2006, 02:18:19 PM
Thanks Roger.
Keep us updated. There are too many different ways of adjusting these things & to a fairly new guy it makes it hard. By the time you take it apart, unsolder & resolder, hook back up & listen it's SOMETIMES hard to tell which one's "better". It's also funny that even unmodified these things are full of color and are very useful but who the hell wouldn't want to make it BETTER? I like the idea of silentarts website of putting it all in one spot. It's a great idea but I'm still unsure all the info there is correct or the best way to go. I was actually going to do the same thing to help people out but it's hard to find the answers. I think people get tired of answering but this would STOP a lot of that.

Kevin
KHStudio
Title: SSL HELP THREAD!!!
Post by: Purusha on February 17, 2006, 05:13:50 PM
Anyone knows what is the angle distance in degrees between steps on the Lorlin rotary switches? I am making the front panel design in Corel and this information would be very helpfull. Anyone?
Title: SSL HELP THREAD!!!
Post by: Purusha on February 17, 2006, 05:17:49 PM
I found it on Lorlin web page  :idea:
Title: SSL HELP THREAD!!!
Post by: Greg on February 17, 2006, 06:53:56 PM
First off, I don't understand why lots of people are using the 2181 when the 2180 is a direct replacement... is it a spec thing?  :roll:

But anyway, I think that Kevin might be misunderstanding what these adjustments are doing. Let me see if I can explain this, and someone correct me if I'm wrong... I haven't used the 2181 I'm just trying to clear up what's been said.

First off, changing the 47K summing resistors is not the main tweak to set the ratios. This is, in fact, used to change the "drive" to the VCAs. Because too much signal to the VCA will cause the "ratio curves" to be really whacky. Perhaps this could cause unwanted saturation in the VCAs, I'm just guessing. I think the sidechain tweak (Steffen) or changing the 1K (SSLTech) are the two methods to actually change the ratios.

Anyway, I say set it... forget it... use it... love it... hate it... time for more DIY !!!
Title: SSL HELP THREAD!!!
Post by: Purusha on February 17, 2006, 07:53:45 PM
I would say because of less distorsion and trimming option ... what the hell do I know, I ordered THAT2181LBs also because of good price and someone mentioned that it doesn't really matter which one you put inside  :roll:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 17, 2006, 09:33:11 PM
Greg,
I was confussed. Your post WAS helpfull. If you read the thread about the ratio's, Roger talked about his method... now when the topic says "How to correct Ratio's that's what I thought he was saying. I don't recall him saying he did the Ratio mods ALONG WITH the CV mod... actually, I've read here a lot and it's news to me about the CV mod.

My question is, if the CV is the same for both 215x & 218x then why isn't this talked about MORE & why isn't it compensated for already on the schematic, layout or the board. It just makes it hard since most are using the newer series VCA's. This is exactly what I'm talking about. It's hard to learn when you only get half the story.

Hey BTW, I got the sidechain boards... Thank you very much.

And , I've asked several times about shorting out where the 10k was and not one responce. More confusion. I really put some time & effort into how I word & apprach my questions so I can learn and not keep asking over & over but I'm getting there in little pieces & I'm very thankful for the help I do get.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 17, 2006, 09:43:21 PM
I'll ask this ONE more time...

Has anyone here ever used, seen, tested or measured a "REAL" SSL (FX384(?) or the new XL series) Rack compressor to see how it works & what the voltages are & types of VCA's used?
Title: SSL HELP THREAD!!!
Post by: gyraf on February 18, 2006, 05:32:11 AM
The "REAL" SSL (FX384(?) is a different beast, unbalanced out etc.. Our is closer to the 4000E. But they sound more or less the same.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 18, 2006, 09:14:49 AM
Gyraf,

Cool, that clears up a little :thumb:


Is the info on the link I posted correct or not? I don't mean to be a PITA but I've asked a few specific questions that are very important to me to learn & can't seem to get a COMPLETE responce...  :sad:

I feel like the 2 units I've built are very close to sounding "right" & the more I understand, the better they'll be... I'll be specific:

How would YOU test & adjust the CV?

I've got the ratio mod down & can see & hear the differences.

Is Roger correct in saying that too high of a CV will overload the VCA's & screw up the curve? I think I'm hearing that. Should I follow his instructions?
Title: SSL HELP THREAD!!!
Post by: khstudio on February 18, 2006, 10:25:33 AM
Are you guys saying to use the 2180 (Pre-trimmed) over the 2181?

Thats what I'm using.

Roger, can I use a volt meter @ the CV input. Now, this is just for the main (Audio) VCA's & not the sidechain? or do I have to adjust for that also?
Title: SSL HELP THREAD!!!
Post by: Eurocide on February 18, 2006, 10:40:27 AM
So, I've started my GSSL for the first time without ICs.
Unfortunately the +DC rail gives a wrong voltage.
(see picture)

(http://www.eurocide.com/public/psu_ssl2.jpg)

The output AC from the transformer is 17V.
The -15 V line works fine but the +15V and both of the 12V lines show only 4.xx V

I've already exchanged the diode bridge with the same result.
Could it be the 7815?

I hope it is just a silly question. :wink:
Title: SSL HELP THREAD!!!
Post by: gyraf on February 18, 2006, 10:42:53 AM
Don't run it without ic's installed - regulators needs some load to work properly. Read this thread - I think we've had this question before..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on February 18, 2006, 10:51:59 AM
Quote from: "khstudio"
Are you guys saying to use the 2180 (Pre-trimmed) over the 2181?

Roger, can I use a volt meter @ the CV input. Now, this is just for the main (Audio) VCA's & not the sidechain? or do I have to adjust for that also?

I'd say yes, use 2180 over 2181. Seems to be less hassle. However, I'd recommend 202 over all, but they're hard to get and more expensive.

I don't like measuring low voltages with a meter. I'd recommend a scope. Whenever measureing small AC, or even AC in general, I like to see the waveform. There could crossover distortion or some oscillation/ringing in there that you won't be able to "see" with a meter.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 18, 2006, 11:50:16 AM
Quote from: "Greg"

I'd say yes, use 2180 over 2181. Seems to be less hassle. However, I'd recommend 202 over all, but they're hard to get and more expensive.



Greg, can you please explain one thing to me regarding the 2180 over 2181. I have a special VCA "color" option in mind for the 8 SSL units which I am building. I will put one extra rotary switch for two different settings of two sets of THD trimmers. So that at the end I can choose a cleaner or dirtier sound of VCAs. That is why I ordered THAT2181LBs, they are not pre trimmed. I can still change the order to THAT2180LBs. My question is - would 2180 VCAs cancel my "color" option from the design because they are pre trimmed or can I still build my SSLs with more or less color option by using the extra trimmers with the 2180?
Title: SSL HELP THREAD!!!
Post by: Eurocide on February 18, 2006, 11:55:29 AM
Quote from: "gyraf"
Don't run it without ic's installed - regulators needs some load to work properly. Read this thread - I think we've had this question before..

Jakob E.

I've put all ICs in.
-15V OK
+15V shows now 2.xx V
-12 V shows 2.xx V
+12 V shows +17 V(!)

I hope I haven't blown any IC now!
Title: SSL HELP THREAD!!!
Post by: gyraf on February 18, 2006, 12:09:18 PM
..So you either have bad regulators or shorts on the board. Shorts are by far the most common..
Title: SSL HELP THREAD!!!
Post by: Purusha on February 18, 2006, 01:39:25 PM
I'll repeat my dilemma since topic moved to next page...

Can you Greg or anyone else, please explain this thing regarding the 2180 over 2181. I have a special VCA "color" add-on option in mind for the 8 SSL units which I am building. I will put one extra rotary switch for two different settings of two sets of THD trimmers. So that at the end I can choose a cleaner or dirtier sound of VCAs. That is why I ordered THAT2181LBs, they are not pre trimmed. I can still change the order to THAT2180LBs on Monday but my question is - would 2180 VCAs cancel my "color" option from the design because they are pre trimmed or can I still build my SSLs with this color option by using the extra trimmers with the 2180?

One more thing regarding the release:
0.1 sek, 0.3 sek, 0.6 sek, 1.2 sek, 2.4(Auto)   ...the last 2.4s is actually in Auto mode, yes?

I need to know because I am doing the design for the front panel.
Title: SSL HELP THREAD!!!
Post by: Greg on February 18, 2006, 03:23:48 PM
Purusha: I cannot answer that question, since I think you're doing something custom. But if you use the 2180, it won't trimmable, if that's what you're asking. I've only built two units without the 2180 and on those I just left the distortion pot in the middle position. So I can't really even comment how that really effects the sound. I guess I don't really care all that much...

I don't know where the 2.4s came from, but the fifth position is the Auto release.

PS - Got the WU today. Also, you don't have post again just because it went to a seperate page... I'll read all posts I haven't already read.  :wink:  Member my patience comment... I was helping my dad pull some new coax through the walls at his house since we had to re-wire the entire place since it flooded.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 18, 2006, 04:23:59 PM
Quote from: "Greg"
Purusha: I cannot answer that question, since I think you're doing something custom. But if you use the 2180, it won't trimmable, if that's what you're asking. I've only built two units without the 2180 and on those I just left the distortion pot in the middle position. So I can't really even comment how that really effects the sound. I guess I don't really care all that much...


I suggested the idea of having one extra potentiometer on the front panel to regulate the THD of the VCA for color here in one thread and got even better idea from somebody to use two set of trimmers inside and just point to them with 2 step rotary switch. It's a simple mod thing, isn't it?
But I guess this would not be possible if I use the 2180 VCAs...

Quote from: "Greg"
I don't know where the 2.4s came from, but the fifth position is the Auto release.


From Gyraf's SSL website... copy paste - 0.1 sek, 0.3 sek, 0.6 sek, 1.2 sek, 2.4(Auto)
Title: SSL HELP THREAD!!!
Post by: Greg on February 18, 2006, 05:11:12 PM
Yup, it's a simple mod, and could definitely be a nice feature, except you wouldn't need a rotary. You could use a toggle and that would save front panel space.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 18, 2006, 05:50:50 PM
Yep, this is also true, but I already bought them and it makes a nice looking design with many buttons  :grin:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 18, 2006, 07:56:18 PM
(http://users.volja.net/purusha/gsslfront.gif)

The idea for the black on gold front panel design. Comments please  :twisted:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 19, 2006, 07:10:39 AM
It looks like I'll be the most frequent visitor in this thread for next few days or even weeks  :grin:

For the external sidechain connections, do I need balanced or unbalanced 1/4 connectors?
Title: SSL HELP THREAD!!!
Post by: Greg on February 19, 2006, 06:07:04 PM
Purusha, you need TRS connectors. One contact for send, one for receive, and the sleeve for ground reference.  :thumb:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 20, 2006, 03:11:41 AM
Oh yeah, what a stupid question, I completely forgot about send/return. Stereo is the way to go then.  :thumb:

Greg, what do you think about my design?
Title: SSL HELP THREAD!!!
Post by: Greg on February 20, 2006, 08:26:52 AM
I think your design is top notch... looks great !!!  :green:

One thing, just in case you didn't think of it. You won't be able to mount the switch daughter board to the front panel because of the location of the ratio switch. So you'll have run wires from the daughter board to the attack, release, and ratio... kind of a pain of the ass, but I've seen several units built like that.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 20, 2006, 09:50:56 AM
Quote
One thing, just in case you didn't think of it. You won't be able to mount the switch daughter board to the front panel because of the location of the ratio switch. So you'll have run wires from the daughter board to the attack, release, and ratio... kind of a pain of the ass, but I've seen several units built like that.


Yes, I know. Distances between pots are also smaller because of few more switches. BTW I don't care about more wires, I like soldering!  :green:
Title: SSL HELP THREAD!!!
Post by: khstudio on February 20, 2006, 03:01:07 PM
Greg,
I just finished loading my 2 sidechain boards & need some help.
Roger talks about adjusting the CV but never mentions having a sidechain installed... did you ever check your CV like Roger recommends & what did you come up with? Having the sidechain installed would change things a bit I'm sure.

And just so I can get this straight, the CV & Ratio's needs to be checked & adjusted for both - 215x & 218x :?: That seems to be what Roger is saying.

I'm sure the info is here somewhere but what's the trimmer for?

Just for the record, I've been leaning towards the newer VCA's - 2180LA, with the 100k to 120k ratio mod it's very nice. I was going to leave 1 unit Gyraf/Stock with 2151 x 3 but the more I listen to the adjusted one I don't like the other as much... maybe I just need the Ratio mod on that one too :?

Anyway, thanks for your help & the boards :thumb:

Kevin
Title: SSL HELP THREAD!!!
Post by: Greg on February 21, 2006, 08:15:28 AM
I personally have not done the "ratio curve" test but when I install my sidechain filters I'll mess around with it a bit.

The sidechain filter shouldn't change much regarding the channel VCAs. Also, the trimmer in there will work kind of like a threshold adjustment. Or it be used the set the highpass exactly to unity gain if that's what is wanted.

It's basically a "set to taste" trim pot.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 21, 2006, 01:30:22 PM
Roger,
I'm on it.
I come back after I check.

Again, thank you for a more detailed responce.

Kevin
Title: SSL HELP THREAD!!!
Post by: khstudio on February 21, 2006, 01:47:18 PM
Greg, Didn't see your post... So the trim sets the gain of the sidechain filter board?

Is the trimmer still active when set to bypass?
 - I think it is but I just want to be sure.

I'm going to attack this CV/Ratio/curve thing as much as I can & when I/we find a good method I'm going to gather ALL the correct info and put it in ONE SPOT to help everyone.

Do you guys think we should continue this discussion in a specific post?

Kevin
Title: SSL HELP THREAD!!!
Post by: Greg on February 21, 2006, 01:58:56 PM
Yes, the trimmer is still active when the sidechain high pass is bypass.
Title: Ordering parts from mouser.com
Post by: Dor on February 21, 2006, 10:07:35 PM
Hello there. I'm ordering my parts for the GSSL off of mouser.com and am running into an issue. i'm searching for part 271-100 but only see 271-100-RC listed at .09 per unit. The 271-100/AP-RC are available but the minimal order is 1000.

Will the 271-100-rc work or do i need the 271-100/AP-RC ?

Thanks,

D
Title: SSL HELP THREAD!!!
Post by: Greg on February 21, 2006, 10:09:09 PM
Yes, it'll work fine. This happens often to me with resistor values from Mouser.

Also, can you add your location to your profile. Thanks.
Title: SSL HELP THREAD!!!
Post by: Dor on February 21, 2006, 10:13:33 PM
Quote from: "Greg"
Yes, it'll work fine. This happens often to me with resistor values from Mouser.

Also, can you add your location to your profile. Thanks.


thanks for the quick response. wasn't sure if I had to have a certain ohm rating ... this is my first DIY  :shock:
Title: SSL HELP THREAD!!!
Post by: TornadoTed on February 22, 2006, 06:38:17 AM
Quote from: "TornadoTed"
I've done a bit of searching around and got totally confused. I've found these on the RS components website, you just need to copy the numbers below into the 'Find products' box at the top of the page.

http://rswww.com/cgi-bin/bv/rswww/home.do?cacheID=ukie


Meter - 1968402
Bezel - 1968682
6 way switch (attack and release) - 665196
3 way switch (ratio) - 665219
Copper foil sheets (the enclosure is wood so I've been told I need copper foil to stop RF and such like - 680959

I already have an account with them so sourcing from them is easier than sourcing elsewhjere if these are suitable.

I'd be so grateful if somebody could check them out for me and let me know if they are what I need for the SSL clone in a 2u case. A friend is building the electronics for me but has left me to get these few bits and pieces. I built the case out of maple, looks stunning. Boy I feel out of my depth  :roll:



Anyone? Please, please, please.
Title: SSL HELP THREAD!!!
Post by: Greg on February 22, 2006, 08:40:39 AM
The meter, bezel, and switches look fine... not sure about the copper foil sheets. Maybe someone else can comment.
Title: SSL HELP THREAD!!!
Post by: TornadoTed on February 22, 2006, 12:36:30 PM
Cheers Greg, much appreciated. I can get the case finished off now and delivered to my mate Jake to stuff the boards.

He has a couple of DBX 202 VCA's that he has had 25+ years. What is there a differnece between these and the 202C?

He is making one to spec and experimenting on other so he may use the 202's in the experimental model.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 22, 2006, 04:53:57 PM
OK,

Been testing my two GSSL's for a few hours & all looks good.

The Control Voltages are perfect on both units.
one has all 2151's & one has all 2180's less trimmer, 68r, 10k & 47r in side chain. I did the 100k to 120k Ratio mod on the one with 2180's & changed the meter resistor to 3k and everything is perfect on that one. The Ratio mod didn't affect the CV at ALL!!! but did fix the ratio's. so all is well.

120mv for 20db compression, 60mv for 10db, 24mv for 4db etc...

Now I'm confussed why some of you had to make adjustments at all?

My last concern before installing Greg/Steffen's sidechain board is:

What's the method of adjusting the distortion trimmers?
I have the audio tester app... can I use that? I would really like to SEE what's going on when adjusted. How?

Kevin
Title: SSL HELP THREAD!!!
Post by: khstudio on February 22, 2006, 05:12:18 PM
Greg,
Could you check your CV @ pin 3 on the audio VCA's. I'd like to know what your getting there with the sidechain filter installed. I'll be installing & testing mine later tonite after my session. I'll report back.

Also, what did you end up with for the meter resistor? I'm using 1ma linear scale.

Thank's
Kevin
Title: SSL HELP THREAD!!!
Post by: Greg on February 22, 2006, 07:31:45 PM
Ted: Not sure about the VCAs  :roll:

Kevin: I think you need a distortion analyzer to set the distortion trims. I don't have one so my trimmers sit in the middle.

I won't be able to check that voltage for you because both my GSSLs are loaned out at the moment. Also, the sidechain should effect nothing at unity gain. What you can do it put a 12K resistor in for the series 1K and 10K trim.
Basically, this is a simple inverting op-amp configuration. If you aren't familiar with it, do a google search and you'll get tons of info. The gain is -Rf/Rin, where Rf is the feedback resistor and Rin is the resistor at the inverting input. Make these values both 12K and you get gain = -1.  :thumb: Or you could put in a 5K and the 10K pot and trim it to exactly -1.

Since I can tell you like things exact, you might want to put something like 5K and the trimpot in the feedback path so can set the gain to exactly -1.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 22, 2006, 11:40:41 PM
Greg,
I wouldn't say exact... this DIY stuff is a great hands on learning tool with great rewards. I've built MANY guitar amps but the LA-2a & above all this SSL comp really opened me up to working with IC's & the VCA's. I've learned so much & love it. To me it's just as much about learning as building, then having more cool equipment for my studio. When you guys say just build it & move on, I'm not with it... I want to dig in a little & learn so the next time I don't have to ask so many questions... not to mention, be more creative in how I mod or adjust my gear.

Isn't the trim there to adjust the gain already?

BTW, I got a lot out of your last post... I don't know ANYTHING about how to set up IC's & their gain's but I'm getting there.

Basically, I just like my gear to work right. The small adjustments I've made so far made the GSSL better for me. Now after measuring the CV & adjusting the meter I've got it to a point where I know it's right & can now move onto the sidechain filter without any added confussion - meaning I'll know where the problem will be (if there is any) without running around the whole board.

If anyone that has the sidechain filter installed can check their CV I'd love to know what your getting to compare. I'll post my results soon.

Thanks again :green:
Kevin
Title: SSL HELP THREAD!!!
Post by: khstudio on February 22, 2006, 11:50:15 PM
OK, I just looked at the schematic & see you can only get 11k total in the feedback as is... so, your saying to increase to 12k to be at unity?

Also, the cap value in the feedback, how does that work? Do higher values add or reduce the higher frequencies?
Title: SSL HELP THREAD!!!
Post by: MRP on February 23, 2006, 12:57:39 AM
I haven't read about this problem yet, so I'm posting it.  I built two GSSLs, neither of which work.  The first isn't even close to functioning properly, but the second one seems promising, even though it's still acting strangely.  Here's what's up with the second

Bypassed, it's nice and clean, makeup gain works fine.
When engaged, all the knobs/switches "work", in that they affect the compression as they should, but the actual compression is crazy.  As I turn the threshold CCW, the audio level goes down, and the meter goes up accordingly.  This is more like turning down the volume though.  When the compression does engage, it totally reduces the gain to nothing, and the meter spikes.   The attack and release controls do affect the speed of the respective spiking timings.  Changing the ratio also makes the meter spike.  Basically, it seems like i'm getting super negative ratios, and it's not tracking properly, as the gain reduction swings are barely related to the source material I'm running through it.
My 15 and 12 voltages seem fine. C and D voltage spikes with the meter/compression.  Diodes are oriented correctly.  Any ideas?
Title: SSL HELP THREAD!!!
Post by: khstudio on February 23, 2006, 01:43:30 AM
I don't think the Make-up Gain should work in Bypass :?
Title: SSL HELP THREAD!!!
Post by: giantbenny on February 23, 2006, 04:31:49 AM
Hi how are you?  I too have had a few minor dramas with a couple of ssl's, i came up with these conclusions but i'll just give them to you in my language.  (idiotnamese)

I added a 22k resistor to pin 3 of the threshold pot (as per advice in this forum)  That settled the threshold issues, next i attached a variable 1k lin pot to the cv 1k resistor located at the bottom of the pcb nearest the vca outline (there are two of course) I then used the pot to isolate the correct resistance that i needed to give me a 2 db drop between the ratio settings by passing through a 1k tone.  My perfect cv resistance was 600R this gave me a much better compressor.  I did tell you i was an idiot and spoke strangely, so if this is wrong, then ah well i tried.

all the best.

ben
Title: SSL HELP THREAD!!!
Post by: MRP on February 23, 2006, 11:36:17 AM
I've got my make-up gain bypass jumpered on the control board until I get everything to work.
Title: SSL HELP THREAD!!!
Post by: MRP on February 23, 2006, 12:39:41 PM
Alright, now a new phenomenon has cropped up.  With no input, the meter is spiking every 4 seconds or so.  Then I put signal through, and it kind of stabilizes, and minutely reacts to the signal, although the baseline of the meter is still inversely proportional to the threshold knob position.  I turn the signal off, and the needle holds and doesn't spike.  Then I test the range of the threshold knob, and the intermittent spiking begins anew.  
After the first GSSL didn't work, I was putting my faith in the second.  Now I want to shoot myself in the face.
Title: SSL HELP THREAD!!!
Post by: khstudio on February 23, 2006, 01:28:26 PM
You have 1 option... Shut it off!

Take your time & go over every little thing. There are a lot of components that have a specific direction - Caps, IC's, Diodes etc...

I built 2 that worked right away but took the time to test EVERY components value before installing. There are soo many things it could be so its going to be hard to help you without a lot more details.

BTW, don't give up, it's probably something small that you're missing.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 23, 2006, 05:53:52 PM
Just to make the right change of 100pF to 100nF. Is this the right spot? If yes, than I need to change two of them in both VCA sections on one PCB?

(http://users.volja.net/purusha/ssl1.jpg)
Title: SSL HELP THREAD!!!
Post by: TornadoTed on February 23, 2006, 06:15:09 PM
I got my my meter for the SSL clone today. It's a Sifam AL29B, it has a 0-30 scale. Does anyone know where I could get a template for a 0-10 scale?
Title: SSL HELP THREAD!!!
Post by: gyraf on February 24, 2006, 03:00:00 AM
Quote
Is this the right spot?


No. Look at the schematic - that is the compensation cap, ic pins5-8.

It's the cap across the 1K feedback resistor that you could change. But it will not matter - leave whatever you have there.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 24, 2006, 05:13:40 AM
Gyraf,

can you please point out on the picture which one of the 100pF is the one to change with 100nF. I already bought the exact number of capacitors and would like to use them accordingly. Sorry for being such an ignorant in this field, but I still don't get what are you trying to explain to me  :oops:  this is my first such project and I still don't understand many things so I need to see this pointed out on the schematic picture.
Title: SSL HELP THREAD!!!
Post by: gyraf on February 24, 2006, 05:33:45 AM
Just put in the value capacitors that are marked at the board, and you'll be OK..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 24, 2006, 06:11:39 AM
Gyraf,

sorry to be so stubborn but I just bought yesterday one of the 100pF less per PCB and one more of 100nF per PCB so I can't just go with the PCB layout at the moment coz I don't have the proper amount of elements needed.

PS: I also don't live in any big town where all the stores are to just jump across the street and buy some more capacitors...
Title: SSL HELP THREAD!!!
Post by: gyraf on February 24, 2006, 06:17:07 AM
Then sub 100p for the 100n (marked .1 on the board) that is in the feedback path (out to inv-input) of the vca-driver 5534. Refer to schematic and layout for position.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 24, 2006, 06:37:58 AM
Jakob,

I give up  :sad: still don't understand a thing where and what exactly...
Title: SSL HELP THREAD!!!
Post by: radiance on February 24, 2006, 07:28:25 AM
Quote from: "Purusha"
Jakob,

I give up  :sad: still don't understand a thing where and what exactly...


No, no , don't give up now. You're about to learn something here...
First check this exelent reading stuff on franks website called
 op amps easy explained.. (http://www.nrgrecording.de/html/op_amps.html).
There you'll find an explanation about the 5534 opamp, which is the opamp Jakob is talking about.
The "vca-driver 5534" is the NE5534 next to the VCA (dbx/that whatever).
In the lower right corner of the GSSL schematic on Jakob's website you'll see the "DBX 2150 to DBX 202 emulation" circuit. The NE5534 in this circuit is the "vca-driver 5534".
Now we need to find the "100n (marked .1 on the board) that is in the feedback path (out to inv-input). Pin 6 on the NE5534 is the output and pin 2 is the inverse input. Between pin 2 and 6 we see a 1K resistor and a 100p cap. This cap is the one Jakob's refering to. It's a little confusing because on the PCB this cap is market as .1 thus beeing 100n.
There've been many questions about whether this cap should be 100p or 100n. I belive the answer was that it can be both...

Now the short answer to your question: it's the cap between the two 1K resistors next to the VCA. On of the two resistors has a * market next to it.
You can ignore the *....
Title: SSL HELP THREAD!!!
Post by: Purusha on February 24, 2006, 09:14:36 AM
Quote
Now the short answer to your question: it's the cap between the two 1K resistors next to the VCA. On of the two resistors has a * market next to it.


This was the answer I was looking for  :grin:  Thanks!

I have another question. All 25 capacitors marked .1 are by default 100n so why am I changing something here at all?

I did have a quick look into Franks website about the 5534 opamps but it's all still like a great unknown world to me ... I guess I don't have the right mind-frame for a DIY knowledge since it all becomes boring to me when matters come to very detailed theoretical fields...

But don't give up on me  :green:
Title: SSL HELP THREAD!!!
Post by: Greg on February 24, 2006, 09:27:45 AM
hi Purusha: Just wanted to offer a bit of advise. When doing a project, never order the EXACT amount for anything, unless it's a very expensive component like a transformer or meter. Always order a few extra resistors, caps, doides, regulators, etc. In the end you might spend a few extra bucks on parts but it can save you some serious time and headaches later. Not to mention you'll build up a nice selection of parts in you own "Lab."  :thumb:
Title: SSL HELP THREAD!!!
Post by: Purusha on February 24, 2006, 10:34:01 AM
You might be right Greg, but I am building 8 units so this adds a little more than just one capacitor or resistor per PCB. I don't know if I will ever again need this things after this project. Although I am thinking already to build a solid state Pultec soon. I also don't like pilling up stuff at home which I almost never use in my life. But thanks for the advise.

BTW. The PCBs for hi-pass came to the Slovenian Custom's office. They are asking me where is the bill for this so they can take some money from me blah, blah,  :twisted:  Did you add any letter in the package?

What about the 25 100n capacitors marked as .1, are this of the same value as the one which is mentioned to replace the 100pF?
Title: SSL HELP THREAD!!!
Post by: Greg on February 24, 2006, 10:56:28 AM
I mean you don't have to buy an extra regulator or part per unit, but for example, just have one or two spare regulators just in case one of the untis decides to blow up... but anyway, this is your biz  :roll:

No I didn't include any paper inside the PCBs.

The 0.1 on the board is 0.1u, which is 100n, so yes to your question. As Jakob told you, you don't need to replace any 100p with 100n. Just put 100p where it says 100p on the board. If you don't have any additional 100p caps, then get 8 more. It might cost you another buck. I personally don't know which cap is in question. I just used 100p... I assume it's omething about high frequency stability.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 24, 2006, 02:41:26 PM
Quote from: "Greg"
I mean you don't have to buy an extra regulator or part per unit, but for example, just have one or two spare regulators just in case one of the untis decides to blow up... but anyway, this is your biz  :roll:


I understand your point believe me, but that is just me...

Quote
No I didn't include any paper inside the PCBs.


Shouldn't be any big problem...

Quote
The 0.1 on the board is 0.1u, which is 100n, so yes to your question. As Jakob told you, you don't need to replace any 100p with 100n. Just put 100p where it says 100p on the board. If you don't have any additional 100p caps, then get 8 more. It might cost you another buck. I personally don't know which cap is in question. I just used 100p... I assume it's omething about high frequency stability.


I see. Thanks.
Title: SSL HELP THREAD!!!
Post by: Purusha on February 28, 2006, 08:10:01 AM
Hello everybody,

Do I need two L/R send/return sockets for the external sidechain or just one?

Thanks.
Title: SSL HELP THREAD!!!
Post by: idylldon on February 28, 2006, 09:57:10 AM
Quote from: "Purusha"
Hello everybody,

Do I need two L/R send/return sockets for the external sidechain or just one?
Thanks.


One stereo jack will suffice.  Use the tip as a send and the ring as the return.  You could also use one mono jack for send and one mono jack for return if you'd rather do it that way, though it's a bit cleaner to do it with the stereo jack.

Cheers,
--
Don
Title: SSL HELP THREAD!!!
Post by: Purusha on February 28, 2006, 11:39:31 AM
Thanks, Don. So there is no separate L and R channel for external sidechain. Than I have to inform the guy who is making all the holes into my many SSL chassis to make one less   :grin:
Title: SSL HELP THREAD!!!
Post by: synthetic on February 28, 2006, 03:01:03 PM
Quote from: "TornadoTed"
I got my my meter for the SSL clone today. It's a Sifam AL29B, it has a 0-30 scale. Does anyone know where I could get a template for a 0-10 scale?


http://www.nrgrecording.de/html/vumeter.html
Title: SSL HELP THREAD!!!
Post by: idylldon on February 28, 2006, 03:44:03 PM
Quote from: "Purusha"
Thanks, Don. So there is no separate L and R channel for external sidechain.


That's correct.  Just one send and receive from whatever outboard filter you're using.

Cheers,
--
Don
Title: SSL HELP THREAD!!!
Post by: Greg on February 28, 2006, 07:55:36 PM
Also, please try to keep all questions regarding the external sidechain high pass in the thread dedicated to that. It's at the bottom in the META. I think it would be better this way since this isn't a standard feature for the SSL, and it would keep all the questions pertaining to the HPF in one place. And also making searching much easier so people won't have to sift through this thread for that info. :thumb:

But yes, idylldon knows what he speaks of !!!
Title: SSL HELP THREAD!!!
Post by: Purusha on February 28, 2006, 07:59:53 PM
Thanks Greg. It makes sense. I am still kinda getting familiar with the forum here.

BTW it's a great place, much appreciated  :thumb:
Title: SSL HELP THREAD!!!
Post by: synthetic on March 01, 2006, 12:32:39 AM
I just read all 90 pages. Woof.

I've read that powering up without ICs is a bad idea. However, I want to test the without converting my endangered DBX202s to puffs of smoke. So would it be alright to switch it on for a while and measure the voltage before plugging in the ICs? I realise that the voltage will be out of whack, but I just want to check for shorts to keep from killing chips.

So, should I just plug in a few op amps to give the regulators a little bit of a load?
Title: SSL HELP THREAD!!!
Post by: gyraf on March 01, 2006, 03:21:28 AM
Just leave the 202's out for initial testing - the load of the other opamps is plenty to get regulation right.

Jakob E.
Title: soft hum in the sidechain
Post by: Ilya on March 01, 2006, 04:43:13 AM
Hi everyone!
Just finished my first GSSL. It's working perfectly, but there's a small issue. It hums (but with really low volume) and the volume of the hum changes with makeup, it also hums in bypass. While checking with a probe (a wire with cap/resistor) I found that the hum originates somwhere in the sidechain circuit. Another strange thing: my lythics have metal lids and when I touch them with the probe some of them hum too, 3 of them are in the PSU in +12/+15 filter section and the loudest hum is from the lid of the cap right after 074 (after vca). I feel that both positive Vregs are hotter than negative.
I just can't locate the source of the hum. My unit isn't racked yet and hum doesn't change if I move my transformer. Maybe a bad cap somwhere? Any ideas?
Title: SSL HELP THREAD!!!
Post by: gyraf on March 01, 2006, 05:06:46 AM
Are your PSU voltages correct?

Does it still hum when you short the inputs to ground (this is the right way of testing)?

Touching the metal on the 'lytics will introduce hum, as they're often connected to one side of the component, and thus to the signal path.

It's hard to judge hum before the unit is boxed in a metal case - I never had any hum problems with this construction when boxed, so maybe you shouldn't worry prematurely..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Ilya on March 01, 2006, 05:27:32 AM
My PSU voltages are ok.
With 'lythics I mean that the hum is directly there - I hear it when I touch them with the probe (and I'm listening to the output of the probe amplifier, not the compressor. And to me it seems strange that only positive half of the PSU hums...
I know that you've never had any hum issues, that's why I'm asking.
And yes, I'm measuring with inputs shorted.
Title: SSL HELP THREAD!!!
Post by: gyraf on March 01, 2006, 05:44:11 AM
Build and box the unit, and then take it from there..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: khstudio on March 01, 2006, 01:59:51 PM
Need Help!

For some reason 1 of my SSL's doesn't seem right  :mad:

I'll explain, I've got 2 unit's. I built them raw with no mods, then slowly did the mods while checking in between to make sure all was well to keep confussion down. Anyway, 1 unit has 2180's & the other 2151's, they both worked great until I installed the sidchain filter board. Now only the 2151 works correctly.

What it's doing:
1 - it does work but lost a little too much punch, with or without the SCFB.
2 - The Threshold is where I notice the bigest problem - I have to crank it WAY past the point I used to - both units used to give me 20db of compression before the halfway point but now this one needs to go to 9:00 or 75% CCW to do it no mods were done here.
3 - I totaly removed the SCFB (side chain filter board) & it's the same
4 - checked for solder problems... non to be found.

This unit was actually my favorite. I'm not sure what to check anymore. I didn't change too much & was very careful. Right now the SCFB is totaly removed & it's still f**d-up.

Any Idea's ????

Anyone with 2180's & NO threshold mod's - Where is your threshold knob sitting for 20db of compression

One more thing, The only odd thing I've done in the past few days was hook up an LED to a short pair of wires so I could move it around the meter to see where it lit it up the best... this was off the LED pads. now when I was moving it around the wire came unsoldered a few time & I don't know if they touched together. Even though the unit almost works right, could I have shorted something? & what should I check?
Title: SSL HELP THREAD!!!
Post by: khstudio on March 01, 2006, 02:07:40 PM
Greg,
the SCFB works great on my one unit... very cool on the drum buss, straight or paralell,  especially when the bass is added in too. I was concerned about the reduced summing resistors from 47k to 20k & how they might affect the "AUDIO PATH" or ruining what I already liked... but all is well, with that unit at least.

Thanks again for the boards.

Kevin
Title: SSL HELP THREAD!!!
Post by: Greg on March 01, 2006, 02:25:58 PM
Not really sure what to tell you. If you install the sidechain high pass at less than unity gain, then it makes sense that you'd have to turn the threshold more to acheive the same compression ratio. However, I have no idea why it would behave the same way if the sidechain was removed.

Quote from: "khstudio"
Greg, the SCFB works great on my one unit... very cool on the drum buss, straight or paralell, especially when the bass is added in too.

Just so there is no confusion, the high pass filter isn't adding any low end, it's actually removing low frequencies from the sidechain. Just wanted to make sure you knew what the filter was doing.  :guinness:
Title: SSL HELP THREAD!!!
Post by: khstudio on March 01, 2006, 02:39:13 PM
Yea, I know what it's doing :wink:
I meant Bass Guitar.


About the levels & threshold -  The unit that's working right has the board installed & the levels are fine + the threashold works like it did before the SCFB. This sucks & I can't figure it out.
Title: SSL HELP THREAD!!!
Post by: khstudio on March 01, 2006, 03:04:48 PM
OK, The voltages @ the wiper/threashold pot are off :!:

The unit thats right:
-10db = .5 volt     (2 o'clock)
-20db =  7.3 volt   (1 o'clock)

The unit thats wrong:
-10db = (neg) - 1.1 volt  (12 o'clock)
-20db =  5.3 volt            (9 o'clock)


Somethings not right.
Title: SSL HELP THREAD!!!
Post by: khstudio on March 01, 2006, 06:58:41 PM
I think I'm getting closer -

At the 15k resistor feeding the "audio VCA's"  & at the summing resistors I'm getting a positive voltage of aprox. 8mv, give or take...

on the bad unit I'm getting NEGative voltage  :shock:  :shock:  :shock:
of aprox. -1 to -3 @ the same spots - voltage varies a little depending on the resistor & wether it's before or after it but you get the idea... it's always negative.

I measured the main voltages @ the important pins & all seems ok
I changed the input IC's & no change
Checked for solder bridges & found nothing

I'm STUCK
 :cry:

HELP
Title: SSL HELP THREAD!!!
Post by: khstudio on March 01, 2006, 11:54:04 PM
Please :sad:

I just left my friends shop after 3 hours of him checking it out & he could find what was causing the problem either & he's no dumb dude. We changed all VCA's & most IC's, check PS, all diodes, you name it. I put it back to stock & still can't get it to respond like it used to. :?  I swear, the units were perfect & ready to rack up & use.

Hopfully one of you guys can help me narrow this thing down?
I am trully lost on this one.

If anyone has a voltage chart or a way of measuring specific areas to narrow it down would be MUCH appreciated.
Title: SSL HELP THREAD!!!
Post by: fenderfred on March 02, 2006, 05:30:30 AM
Hi!
i'm going to start a GssL and i get some of the parts needed.
I received a W08(800v) in stead of W04(400v).
Will it work correctly?or not?
Thanks
Title: SSL HELP THREAD!!!
Post by: mathflan on March 02, 2006, 05:55:52 AM
Hi fenderfred

I'm french too from saint etienne, if you want, I can Give you one W04.
I don't know if the W08 will works...
Title: SSL HELP THREAD!!!
Post by: Ilya on March 02, 2006, 08:29:29 AM
Hi, fenderfred
W08 will do just fine. It's rated for 800V which is 2 times more than 400V...
Title: SSL HELP THREAD!!!
Post by: Greg on March 02, 2006, 08:55:48 AM
hi khstudio:
I got one of my SSLs back the other day, and it has 2180LBs in it, so let me know what voltages would be helpful to you and I can measure them for you soon.
Title: SSL HELP THREAD!!!
Post by: mathflan on March 02, 2006, 09:45:28 AM
I have just finished my SSL :grin:

It' huge!

I have two questions :

- I'd like to remove the big "tick" noise when I power Off the SSL, any idea?

- How can I Verify if my high pass sidechain from greg works?
Just put an CD for example in the KEy input?

thanks
Title: newbie help!
Post by: dax on March 02, 2006, 04:41:00 PM
This is my First SSL build and i have been trouble shooting / reading this long thread for about a week. My comp is passing audio but only the makeup gain works (threshold affects some volatages but not the audio)
no compression, meter etc...
i have treid swapping out all VCA's and IC's and am positive they are oreinted correctly. I have also treid replacing the bridge rectifier and the regulators and some cas around them
My continuity meter tell me the -15v rail is shorted to gorund but i cant find where??? here are my voltage readings....(with audio passing)

5534s
1. 12.05
2. -0.00
3. -0.00
4. -15.00
5. 0.60
6. 0.00
7. 14.65
8. 12.05

5532s
1. -0
2. 0
3. 0
4. -15.00
5. 0
6. -0
7. 0
8. 14.66

TL074
1. 0.04
2. -0.00
3. 0.00
4. 12.21
5. 0.00
6. 0.00
7. -0.84 vari to 0.00 with threshold
8. 0.00*seems wrong
9. 0.00
10. 0.00
11. -12.18
12. 0.00
13. -0.00
14. 0.63

Tl072
1. -3.08 vari to 3.08 with thresh
2. -0.00
3. 0.00
4. -12.16
5. 0.00
6. -0.00* seems wrong
7. -0.00 vari to 1.96 with makeup
8. 12.22

VCA Section
5534s
1. 12.03
2. -0.00 vari to -0.09 with makeup
3. -0.00 vari to -0.09 with makeup
4. -15.00
5. -0.70 vari to -0.60 with makeup
6. -0.00 vari to -0.09 with makeup
7. 14.66
8. 12.03

that 2181s
1. -0.00
2. 0.00
3. 0.00 vari to -0.09 with makeup
4. 0.00
5. -2.69* seems wrong
6. 0.00
7. 14.68
8. 0.00

SC 2181
1. 0.00
2. 0.00
3. 0.00
4. 0.00
5. -2.69
6. 0.00
7. 12.22
8. 0.00

Connectors to controls
c. 0.00
b. -2.90 vari to -10.20 with threshold
a. 3.70 vari to 0.00 with threshold
0. 0.00
-. -12.18
d. 0.00
g. 0.00
e. 12.21 vari to 0.00 with makeup
f. 12.21 vari to -12.18 with threshold

...any help is greatly appreciated thanks in advance
daniel mc

+. 12.21
Title: SSL HELP THREAD!!!
Post by: mathflan on March 02, 2006, 06:23:39 PM
Hi,

My SSL comp works fine but

I have a little noise problem when I activate the SSL compressor,

I recorded an MP3, with the make up gain at maximum.

http://sounddiy.free.fr/images/montage/SSL/SSL%20NOISE.mp3

The noise doesn't come from PC monitors or other parasite objects, I powered off ALL, check all.

It's maybe a ground loops?

- the chassis of the XLR inputs and outputs are connnected to the RACK chassis by XLR screw.

- I connected the PCB ground input on only input XLR.

- I disconnected the PCB ground Output.

- The EARTH is connected to the rack chassis by the screw of the Europa connectic.

- I use a RELAY Board. I connected the Ground of The PCB to the Ground of the relay board.

My toroid transformer is far from PCB but close to Outputs XLR, some Centimeters...

any idea? :cry:
Title: SSL HELP THREAD!!!
Post by: mathflan on March 02, 2006, 06:41:21 PM
ok

The noise is not cause by the toroid transformer, I move it but stil have noise.

In fact I'am wondering if it's not cause by the SSL highpass filter from Greg.

I put the Ground of the JAck, send , return to the star ground and did the same to the ground of the SSL high pass filter.

I'am wondering too if I have to use Shielded cable for the Relay board


Hey DAX, you 're not from audiofanzine??
Title: SSL HELP THREAD!!!
Post by: khstudio on March 02, 2006, 11:10:49 PM
Greg,
Thanks for responding :thumb:

After HOURS :evil:  of troubleshooting I found it has nothing to do with the main circuit board... it's the control panel. I still don't know what but I'll find it. I didn't look there because it had been working fine & I didn't do any work there or even remove it... BUT, not that it's a big deal, I found that the unit with the 218x VCA's has a negative voltage everywhere from the output electro cap right after the 1st 5534's thru the 15/27k resistors, thru the summing resistors up to the sidechain VCA & the one with the 2151's has a POSitive voltage in those spots. When I was poking aroud trying to find why the Threashold was way off I noticed this & thought it was a problem but it ends up that it's NOT :shock:  I finally pluged the board into the working (corectly) units front panel & it kicked ass :green: .

So, the voltage difference sidetracked me & must be ok. It was the front control board the whole time.

I still would like to see if anyone else is getting a positive or negative DC voltage in those area's. It could be the different VCA's or the distortion trim circuit being there or not... who knows.

I think my new quote will be "Solid state ain't easy to troubleshoot"
Title: What is the THRUST mod as opposed to the Sidechain mod?
Post by: Bluzzi on March 03, 2006, 03:27:16 PM
Just a question here. I know that the Sidechain is just a high pass filter to affect the way the compressor behaves but what does the TRUST mod do?

Jim
Title: SSL HELP THREAD!!!
Post by: gyraf on March 04, 2006, 05:14:50 AM
..the same, just a softer (3dB/Oct) filter..
Title: SSlL Finally done... Voltage problems...please help!
Post by: AudioguyII on March 04, 2006, 02:21:21 PM
So excited I finally finished my first SSL.... (please excuse my newbieness)
When I test voltage I get 9.4V instead of 15 V.
Any ideas why?
I'm using the MT2086 from Jaycar. Wired with yellow on Pin 1, red- pin 2, white Pin 3, and Purple Pin 4.
What other test sould I perform before inserting VCAs and likes?

Thank you!!!

Excited Newbie.
Title: SSL HELP THREAD!!!
Post by: mathflan on March 06, 2006, 02:47:55 AM
Audioguy what voltage do you have at the output of your transformer??

with Alternative voltage scale on multimeter...
Title: SSL HELP THREAD!!!
Post by: mathflan on March 06, 2006, 02:53:24 AM
I Post a thread "SSL comp noise due to The Bypass LED switch"

I put the diagram here, (better place ) of my Mounting of the SSL.

I have a noise ( 100Hz or 200Hz ) when I put the Makeup at MAX, When I put a 0Db signal, the noise is at very low volume  but I'm afraid that when I will use my SSL on big system,, the noise will become listenable.

I'd like to know If I made something wrong,:roll:

Thanks if you can take time to watch this :


(http://sounddiy.free.fr/images/montage/SSL/SSL%20Plan.jpg)
Title: SSL HELP THREAD!!!
Post by: 5meo-geo on March 06, 2006, 07:26:07 AM
Audioguy where did u connected it???

check for shorts
and also check id 7812 and 7815 connected right way

i had simular problem with negative voltages
7912 was connected wrong way
Title: SSL HELP THREAD!!!
Post by: AudioguyII on March 06, 2006, 09:05:25 AM
Hey Guys,
Thank you so much for getting back to me...
This has been driving me crazy.
The transformer is from Jaycar  MT2086 .
Tried connecting to both locations on PCB. now it's at the corner/"external transformer" spot.
I connected the yellow and white together to form center tap (these are the "0" wires) then purple and red go to the extremetie of the connector.
I get a reading of 8.47V from testing yellow/white (connected together) and purple .
and a reading of 8.47V from yellow/white(connected together) and red.

My 78L12 and 79L12 seem correct. Flat part facing in.
I have not installed VCAs or connecteted XLRs, or ground.

I've checked soldering and it lloks good. Haven't gone through to verify if components are all a right location but I did check and recheck as I stuffed the board.

Of course this all happens when I need this SSL to do a mix with a looming deadline..... please help me save $$$ and not have to go buy a stereo comp!!!!

Thanks guys!

AudioguyII
Title: SSL HELP THREAD!!!
Post by: smallbutfine on March 06, 2006, 01:08:20 PM
mathflan, what is your opinion about the star point you are using? I would, if i were you,  i would take a thick piece of green-yellow covered copper cable and strap the grounds together at the point on the left of the IEC plug and not at pin 1 of the first XLR in. strange (in my opinion) is that you didn't ground the key in directly to chassis like the xlr's, but to pin 1 of the first XLR. This is not making sense to me at all but maybe i'm just blocked at the moment...

I've not looked too long on your diagram, so maybe i overlooked something someone else will find...

If you just want to find out, if the grounding scheme is the source of noise or the relay boards, i would simply groundlift (only) the in's completely for troubleshooting and listen again. Is the noise/hum still remaining? what relais are you using?

Kind regards and successful troubleshooting :thumb:

Martin
Title: SSL HELP THREAD!!!
Post by: mathflan on March 06, 2006, 09:01:31 PM
HI smallbutfine, Thanks for the answer.

In fact the KEy input I use is a JACK connection with plastic lug so I have to connect the Pin 1 of this JACK to the star grounding.

In fact my problem is that My XLR are connected to the chassis by themselves when I screw them.
Perhaps I have to Put some scotch around XLR LUG so as to BE not connected to the chassis.
By doing that, I could Connected the Chassis of the XLR at only ONE point.

I Tried a lot of thing to See where the noise come from, But I don't have disconnect the Relay board, I'll try...

I use MT2 AXICOM, TYCO
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 07, 2006, 11:19:11 AM
Quote from: "AudioguyII"
Hey Guys,
Thank you so much for getting back to me...
This has been driving me crazy.
The transformer is from Jaycar  MT2086 .
Tried connecting to both locations on PCB. now it's at the corner/"external transformer" spot.
I connected the yellow and white together to form center tap (these are the "0" wires) then purple and red go to the extremetie of the connector.
I get a reading of 8.47V from testing yellow/white (connected together) and purple .
and a reading of 8.47V from yellow/white(connected together) and red.



I had this wrong when I first built my first GSSL. I have the same jaycar toroid.

I've got it wire:

red/white tied together for - 0V (middle)
purple                             - 15V (outside pin)
yellow                             - 15V (outside pin)

This should work.
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 07, 2006, 11:27:25 AM
Now I'll ask my own question....

On the gssl pcb it's marked (in the area for pcb mounted toroid) that a 4.5VA toroid will do.

I've got the above mentioned MT2086 toroid which is a 15v-0-15v 20VA. Is it safe for me to assume that if the gssl only requires 4.5VA I'll be able to power 2 gssl's with this one toroid?

Also how might I go about calculating if a PSU pcb (in this case Keith's SSL 9K PSU pcb (thanks Neeno for the idea)) will handle 2 gssl's?

Thanks in advance

Steve
Title: SSL HELP THREAD!!!
Post by: AudioguyII on March 07, 2006, 11:33:21 AM
Thanks BladeSG,

I also realize I just made a huge error. I live in NY , USA 120V . Not 240V input. I thought this transformer was able to handle all input. So I think I'm only getting half due to this.
I connected it in series and got 16.5V output.... so..... After thinking about it ... I have a few of these transformers. So I  took two... I connected their respective red and white together , connected the 2 yellow togther from the two, which leaves me with 2 purple at 16.5V.
I connected the 2 yellow to center tap and the two purples to the live extremities.  I finally got 14.9V and -14.9V on my 15V rails, but I get -20V on my 12V rail, and now my LED doesn't light up. It did before when I got 10V on the 12 V rail.
What am I doing wrong....
I've searched the thread but can't find my solution...
Please help.

AudioguyII
Title: SSL HELP THREAD!!!
Post by: AudioguyII on March 07, 2006, 11:37:30 AM
Sorry, 12 V rail is measuring 21.7V to ) pin on the input XLR
Title: SSL HELP THREAD!!!
Post by: ioaudio on March 07, 2006, 12:37:32 PM
i got a gssl from a friend, he couldnt make it work. i found 7 solder bridges and some resistors with the wrong value.

fixed it, powered it up but no work.
 i read +0,6 volt on the positive +15Volt rail and -9,79 on the negative -15 rail. couldnt find any further solder bridges, ac on secondary of the trafo is ok.
are the regulators gone?

any help appreciated,
max

edit: just found out that the original trafo, which supposed to have 2x18 volt, gave me 28 volt AC unloaded. did this fry the regulators?
Title: SSL HELP THREAD!!!
Post by: Greg on March 07, 2006, 12:59:21 PM
Actually the power trafo on the GSSL is 15-0-15, not 18-0-18. If you're getting 28-0-28 you'd be dissapating alot of heat and the regulators might be toast, so a regulator swap is not be a bad idea. Are the regulators measuring a short or open circuit?

@Audioguy, I'd recommend getting the correct power tranny for 110/120 before proceeding.
Title: SSL HELP THREAD!!!
Post by: Eurocide on March 07, 2006, 01:00:42 PM
Quote from: "BladeSG"
Quote from: "AudioguyII"
Hey Guys,
Thank you so much for getting back to me...
This has been driving me crazy.
The transformer is from Jaycar  MT2086 .
Tried connecting to both locations on PCB. now it's at the corner/"external transformer" spot.
I connected the yellow and white together to form center tap (these are the "0" wires) then purple and red go to the extremetie of the connector.
I get a reading of 8.47V from testing yellow/white (connected together) and purple .
and a reading of 8.47V from yellow/white(connected together) and red.



I had this wrong when I first built my first GSSL. I have the same jaycar toroid.

I've got it wire:

red/white tied together for - 0V (middle)
purple                             - 15V (outside pin)
yellow                             - 15V (outside pin)

This should work.

what a funny coincident. It was my main error, too! Now all voltages are fine! Learning by doing :oops:
I've found the solution on page 40 of this thread.
Title: SSL HELP THREAD!!!
Post by: ioaudio on March 07, 2006, 01:07:50 PM
thanks greg !
already replaced the transformer with 2x15v. the regulators do not measure a short, nor do the voltage lines.
its much more difficult to trace something you didnt build yourself...

edit: found out that the voltages are ok when i lift the -15v wire bridge next to the two 47k resistors. resistance to ground is 800R at that point.
Title: SSL HELP THREAD!!!
Post by: AudioguyII on March 07, 2006, 04:11:15 PM
Hey Greg,
Thanks, I wish I could find a place that has them in stock... if you know of somewhere, I'd appreciate it. Digikey is out.
So using two wouldn't do the trick?
Title: SSL HELP THREAD!!!
Post by: dissonantstring on March 07, 2006, 04:17:28 PM
audioguyII,
try avel lindberg: http://www.avellindberg.com/transformers/y23_range_specs.htm
or parts express might have them (they carry avel lindberg too, but you can get them direct).
regards,
grant
Title: SSL HELP THREAD!!!
Post by: Greg on March 07, 2006, 04:20:20 PM
I like these better than the Amveco from Digikey.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=122-605
Title: SSL HELP THREAD!!!
Post by: AudioguyII on March 07, 2006, 04:39:38 PM
Thanks Greg,
Just ordered them...... hope this cures all my ills!

AudioguyII
Title: SSL HELP THREAD!!!
Post by: ioaudio on March 07, 2006, 07:42:09 PM
6 hours of error tracing... found the problem, a bad `lytic...thanks for your attention...
Title: SSL HELP THREAD!!!
Post by: Greg on March 07, 2006, 07:56:30 PM
Fantastic... was it shorted or open or leaky?
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 07, 2006, 08:06:05 PM
Quote from: "BladeSG"
Now I'll ask my own question....

On the gssl pcb it's marked (in the area for pcb mounted toroid) that a 4.5VA toroid will do.

I've got the above mentioned MT2086 toroid which is a 15v-0-15v 20VA. Is it safe for me to assume that if the gssl only requires 4.5VA I'll be able to power 2 gssl's with this one toroid?

Also how might I go about calculating if a PSU pcb (in this case Keith's SSL 9K PSU pcb (thanks Neeno for the idea)) will handle 2 gssl's?

Thanks in advance

Steve


Would it be easier/smarter to just leave the PSU sections of the gssl's intact and use 2 toroids?

Steve
Title: SSL HELP THREAD!!!
Post by: gyraf on March 08, 2006, 04:27:40 AM
Quote
Would it be easier/smarter to just leave the PSU sections of the gssl's intact and use 2 toroids?


Yes. Feeding two bridge rectifiers from the same transformer windings can give unpredictable results.

The 4.5VA is approx. the power drain of the circuit - but this is EXCLUDING any power needed to light the meter..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 04:40:42 AM
Thanks Jakob.

I was thinking of only using the one PSU pcb, one bridge and one toroid feeding 2 gssl's.

Still easier to use 2 toroids?

Steve
Title: SSL HELP THREAD!!!
Post by: gyraf on March 08, 2006, 07:18:09 AM
Depends on your error-tracing skills. It's absolutely possible with one toroid, but potentially troublesome.

If you do this, use rectifier on only one board, and distribute unregulated DC to the other board. Maybe double reservoir capacitors to 2200/35V.

Are you building a quad compressor?

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mathflan on March 08, 2006, 07:29:24 AM
HI,

I did the trick of Replace the 100 K resistor by a 120k for correct ratio but I need to Calibrate my meter.

the meter is at his maximum when I have 5dB of compression.


DO you know How can Set it.

It's a 1mA meter, I use a 2Kresistor for the sensitivity.

Thanks
Title: SSL HELP THREAD!!!
Post by: Greg on March 08, 2006, 07:59:16 AM
Put a trim pot in for the 2K and as you reduce the resistance you'll see that at full deflection your "dB" will go up.  :thumb:

I've had to tweak this for every GSSL I've built.
Title: SSL HELP THREAD!!!
Post by: mathflan on March 08, 2006, 08:05:30 AM
thanks greg!
it's work great!!


 :grin:

I find a software called DDF3 from YMEC, there a trial full version of this.

I use it for THD trimmer, it's works great


http://www.ymec.com/products/dssf3e/index.htm
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 08:11:04 AM
Quote from: "gyraf"
Depends on your error-tracing skills. It's absolutely possible with one toroid, but potentially troublesome.

If you do this, use rectifier on only one board, and distribute unregulated DC to the other board. Maybe double reservoir capacitors to 2200/35V.

Are you building a quad compressor?

Jakob E.


Thanks Jakob, I appreciate your help.

Are you building a quad compressor?

Yes, or is called a dual stereo compressor?

Anyhow (with the help of Neeno with the 4 jumpers) this is what I'm thinking might work: (I should mention in my quick hack below that the jumpers of the 7815 and 7915 are straight from input pin to output pin, I went of the 7815 part with the yellow line)

(http://img.photobucket.com/albums/v481/bladesg/GSSLPSUMod_2.jpg)

Will this work or am I dreamin'? I'm thinking it will if the 20VA toroid is enough and I'm unsure about leaving the 2 x 22uF/25V caps in the PSU section of the GSSL's PCB.
Title: SSL HELP THREAD!!!
Post by: Greg on March 08, 2006, 09:57:56 AM
I think this looks fine for the +/-15VDC. But the GSSL also needs +/-12VDC... I don't see a PSU supplying that as well ?!?
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 04:27:26 PM
Quote from: "Greg"
I think this looks fine for the +/-15VDC. But the GSSL also needs +/-12VDC... I don't see a PSU supplying that as well ?!?


I thought the same way as normal, through the 2 x 10R resistors....?
Title: SSL HELP THREAD!!!
Post by: Greg on March 08, 2006, 04:45:56 PM
If you notice from the schematic, the 10R are being pulled pre-regulation. I think the way you have it set up 10R will be connected to the regulated +/-15VDC.
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 04:57:51 PM
Quote from: "Greg"
If you notice from the schematic, the 10R are being pulled pre-regulation. I think the way you have it set up 10R will be connected to the regulated +/-15VDC.


Thanks Greg. You're right, another oversight. It's so obvious too :oops:

I suppose then it's 2 toroids, which is a shame....
Title: SSL HELP THREAD!!!
Post by: khstudio on March 08, 2006, 05:00:26 PM
Quote from: "mathflan"
HI,

I did the trick of Replace the 100 K resistor by a 120k for correct ratio but I need to Calibrate my meter.

the meter is at his maximum when I have 5dB of compression.


DO you know How can Set it.

It's a 1mA meter, I use a 2Kresistor for the sensitivity.

Thanks


I used a 127k in that spot. 3k for the meter put me dead on on both of my units. One uses 2180's & the other 2151's. :green:
Title: SSL HELP THREAD!!!
Post by: ioaudio on March 08, 2006, 05:00:31 PM
i think you should split the voltages before the regulators. double the filter caps (2200µ) and regulate twice, +/- 15v and +/- 12v
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 05:37:28 PM
Quote from: "ioaudio"
i think you should split the voltages before the regulators. double the filter caps (2200µ) and regulate twice, +/- 15v and +/- 12v


Thanks ioaudio.

How about if I leave the LM7815 and LM7915 regs on the gssl's and use Keith's 9K PSU (remove regs from here and jumper input and output) to feed unregulated 15-0-15 DC to the 2 gssl's. So all I'd be removing from gssl pcb's would be the bridge and the 2 x 1000uF caps. There would only be one bridge on the PSU pcb.

Are you suggesting using 2200uF caps in place of the 1000uF's?

Thanks in advance.

Steve
Title: SSL HELP THREAD!!!
Post by: ioaudio on March 08, 2006, 06:00:49 PM
leave out the rectifier on ssl#2 and connect the unregulated +/- lines(from the 1000µ caps) to ssl#1 (to 1000µ caps).
Title: SSL HELP THREAD!!!
Post by: Lowfreq on March 08, 2006, 06:08:35 PM
Another note of frustration here..........

I posted this a while back, so bear with me again. I haven't touched my GSSL in a while coz this one stumped me, but I'm determined to get it sorted. :twisted:

My main problem is with my ratios. 1:2 & 1:4 give me no signal at all, where as 1:10 does, and when I flick back from the non-workin ratios to 1:10 it seems to fade in (is that a cap filling up?) :roll:

Now Jakob suggested checking my switch with an Ohmeter, which i did and everything seemed all good. I've also checked the voltages too at the threshold pot getting +12v & -12v as in the schemo.

Now I've looked at the schemo and I'm pretty sure that the ratio is really only effected by the 510k,270k,1M2,1M8 & 3M9 resistors. I've checked the components thoroughly to make sure they correct and they're spot on.
It just seems weird that only one ratio works. I've checked for shorts again and again. :?

I will keep lookin and testing, but my main question is...... Am I looking in right place? It's really just those resistors that effect ratio right? Or is there somewhere else I've missed?

Again, any comments or a slap in the face is greatly appreciated :wink:

regards,

Steve
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 06:16:32 PM
Quote from: "ioaudio"
leave out the rectifier on ssl#2 and connect the unregulated +/- lines(from the 1000µ caps) to ssl#1 (to 1000µ caps).


Thanks, but I'm not sure I understand what you're saying.

I think it's going to be much easier if I just buy another toroid and leave the gssl psu as is.

Steve
Title: SSL HELP THREAD!!!
Post by: ioaudio on March 08, 2006, 06:42:53 PM
sorry to be cryptic.

(http://groupdiy.twin-x.com/albums/userpics/10055/ssl3%20copy.jpg)

thats the way i would wire it. build both ssls completely, only leave out the rectifier on ssl#2. keep the 1000µ caps, the regulators, everything except that second rectifier.
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 07:43:11 PM
Thanks ioaudio, I can understand that.

I've modified my pic quickly:

(http://img.photobucket.com/albums/v481/bladesg/GSSLPSUMod_3.jpg)

Will this way be easier or even work?

Steve
Title: SSL HELP THREAD!!!
Post by: Greg on March 08, 2006, 10:38:46 PM
I think that looks pretty good... feeding each PSU with unregulated DC. But definitely test the PSU before putting in the ICs just to make sure everything is ok.  :thumb:
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 08, 2006, 11:00:33 PM
Thanks Greg for the tip on the +/-12V supply. I can't believe I missed that before. I'm going to give a go this afternoon if I get time and see if it works....

Steve
Title: SSL HELP THREAD!!!
Post by: mathflan on March 09, 2006, 02:29:14 AM
Lowfreq, if your components looks good and that you have verified your Ratio potentiometer



Check all the Traces of your PCB, there's maybe a short cut between two traces... :roll:
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 09, 2006, 10:31:12 AM
I built the (pic above) 9K PSU earlier today minus the regulators (jumpered) and minus the +48V section. I didn't have any 2200uF electrolytics on hand so I used a couple of 1000uF/50V. I also used a W06 bridge instead of the W04, and .1uF/63V MKT's.

I did not connect it to the 2 GSSL's and test yet. With the 15-0-15 20VA (jaycar MT2086) it's putting out +/- 22.5V unregulated DC.

How would I go about working out if it needs 2200uF/35V electrolytics and if the .1uF/63V are the right values to use.

Both Jakob and ioaudio suggested using 2200uF, but how did they work this out?

Thanks

Steve
Title: SSL HELP THREAD!!!
Post by: gyraf on March 09, 2006, 03:30:42 PM
the 2200uF is to get equal powersupply regulation at double current drain..
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 09, 2006, 08:03:02 PM
Thanks gain Jakob. :thumb:
Title: SSL HELP THREAD!!!
Post by: mathflan on March 10, 2006, 06:18:12 AM
I don't know if it's the right to talk about this but I'd like to have some advice to use the SSL comp for mixing or mastering.

I use my SSL at the master of my MIX but I'am wondering what is the best place on the audio chain to put my SSL.

I'am wondering too if I have to use 4:1 or 2:1 on my mix since I will put some compression again when I will do the mastering..

Thanks if you have good advice to use the ssl at his best.

 :grin:
Title: SSL HELP THREAD!!!
Post by: laus on March 10, 2006, 01:30:40 PM
Hello

I'm wiring my SSL clone and I would like to put the bypass swith (wich defeat makeup gain) with a bypass led but I don't know how to do this.
If anyone can help me it would be great.

Thanks**Laus
Title: SSL HELP THREAD!!!
Post by: AudioguyII on March 10, 2006, 05:46:27 PM
Hey Greg,
Thanks again for the part number... I got the trannys today.
15V rail is good... btu 12V rail is now 24V..... and -12Vrail is registering mv.
As I am new to this...please excuse my ignorance, I am testing each rail to the "0" on the input socket where XLRs will be connected...correct?

Thanks
Title: SSL HELP THREAD!!!
Post by: fucanay on March 11, 2006, 11:42:28 PM
I just fired up my first of 2 SSLs today. And I got nothing. No sound at all. No distortion, no audio, no hiss, no buzz. Nothing. On either channel.  :sad:  :sad:  :sad:

I don't want to ask for specific advice, as there is so much here. But in order for me to trace this, I would like to know a couple general things.

1. Will a channel (left/right) pass audio even if the control board or sidechain have issues?

2. Would removing the control board help in finding the problem with not passing signal? Meaning, if there was multiple problems, would eliminating this portion of the circuit refine my search a little?

Right now, I'm going to do what I can to get the voltages of the ICs and make sure they match what everyone else has. I hope eliminating that will help.

Thanks,

Matt
Title: SSL HELP THREAD!!!
Post by: fucanay on March 12, 2006, 01:32:22 AM
Umm, I'm a retard. I'm almost too embarrassed to talk about it, but I hooked the In's to the Outs on my sound card. I had labeled them while really tired and it was all backwards. So it passes signal fine and my meter work. It sounds like there is some distortion, but I'll narrow down that stuff soon.

Thanks for reading.  :oops:  :oops:

Matt
Title: SSL HELP THREAD!!!
Post by: fucanay on March 12, 2006, 03:42:00 AM
Ok, more tests done. I had a grounding problem with the TRS jacks that I'm using. One of the inputs wasn't tightened to the case enough and therefor causing drop outs.

This leads me to another question though. If the TRS jack is grounding to the chassis, do I also need to ground it to the ground terminal on the IEC socket? Does that create a loop or is it just double grounding?

The SSL sounds amazing to my ears. It has no hum that I can hear. I'm really happy with how it sounds so far. Thanks to everyone that wrote even a single post in this thread (they all help). An extra big thanks to Jakob for creating this project and to Gustav for providing the PCBs. I am very grateful to you all.

Matt
Title: SSL HELP THREAD!!!
Post by: fucanay on March 12, 2006, 11:42:58 AM
Quote from: "RogerFoote"
Quote from: "fucanay"
Ok, more tests done. I had a grounding problem with the TRS jacks that I'm using. One of the inputs wasn't tightened to the case enough and therefor causing drop outs.

This leads me to another question though. If the TRS jack is grounding to the chassis, do I also need to ground it to the ground terminal on the IEC socket? Does that create a loop or is it just double grounding?

Matt


I always use connectors that do not ground to the chassis when mounted. I.e. TRS jacks with plastic, insulated bushings.

If you get it to sound right, leave it the way it is. The only time to run a gnd from a connector to the panel seperately is when you use a non conductive bushing or you might get a ground loop in your Gssl.

The basic idea is One Ground Path Only!


Noted. After I'm out of these jacks I'll switch to the other kind and I'll just tighten the crap out of these ones to make sure they don't come loose. I am so amazed how good this thing sounds.

Thanks again for the help.

Matt
Title: SSL HELP THREAD!!!
Post by: BR on March 13, 2006, 12:22:00 AM
Hey there guys,
I just asked Greg for some personal help with some problems I'm having with 2 SSL clones I'm building,  since I was afraid of sounding really dumb on the forum.   But since, I can really hide it anyways, I thought I should ask here too.  Maybe others with similar problems can benefit..

I have 2 units but I'm only going to describe one at the moment.

I have no way to do audio testing at home, so I just decided to start with power and this is what I found:..

7815   23.7V In  and 14.7V Out
7915  -23.6V In and -14.9V Out

78L12  23.5V In and 12.2V Out
79L12  -23.5V In and 12.0V Out

I basically comcluded that my power rails are fine with regulators working correctly.

I moved on to checking power at the ICs (with chips in sockets)  and this is what I got:

5534  Left input
Pin4   -14.97V
Pin7   14.78V

5534 Right input
Pin4   -14.97V
Pin7   14.77V

5532 Left out
Pin4   -14.97V
Pin8   14.77V

5532 Right out
Pin4   -14.97V
Pin8   14.77V

So I guess it is safe to assume that everything is going fine up to there.  

TL072
Pin4   -12.07V
Pin8   12.21V

TL074
Pin4   12.22V
Pin11 -12.07V

I guess everything fine here too..

Time for sidechain VCA

Pin5  -8.62V  (?)
Pin7  12.22V

So I figured there is something funky between the output of my 79L12 and the SC VCA but I couldn't find anything... hang on,  I'll take another look..
So, by looking at the schem and pcb, I noticed the 3k9 resistor in series with Pin5 of the VCA.  That could be what is causing the voltage drop, right?  if so, then this reading is correct, right??


I went on to measure the Voltage points that are labeled on the pcb, just to see if everything was OK and poked around and remember something about the Voltage labels on the bottom of the unit not being exactly next to the voltage points.  So I measured around on the spots that I thought should be read and they all seem fine.

I guess my questions,  after this long description,  is the -8.6V on the SC VCA any concern?  and is there anything else, power wise, that I should check for??

maybe some DC on the other pins of the chips or anything like that?

WOW.. I just learned so much doing this... this is great.


Thanks a bunch

Gil
Title: SSL HELP THREAD!!!
Post by: gyraf on March 13, 2006, 03:17:29 AM
Hi Gil,

Quote
is the -8.6V on the SC VCA any concern?


Normal. Check the data sheet for the VCA - and/or take a look st the schematic. It all has a good reason  :grin:

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Pri on March 13, 2006, 02:25:25 PM
Hi guys,
I just came around to thank all of you. I just got the transformer, hook it all up and it work right away and it sounds great. I'll post some pictures when i have the case
thanx again jakob, gustav, jaydee and all of you

Niklas
Title: SSL HELP THREAD!!!
Post by: gyraf on March 13, 2006, 02:40:35 PM
:thumb:
Title: SSL HELP THREAD!!!
Post by: 5meo-geo on March 14, 2006, 08:32:38 AM
ello folks
i have a small question to ask (maybe its been discussed earlier but i couldnt find it in this topic)

what changes i need to make to use 0.2 mA meter coil???

thanks in advance
Title: SSL HELP THREAD!!!
Post by: mathflan on March 16, 2006, 09:08:46 AM
put a 2K trimmer instead of the 2 K meter resistor, see schematics.
CAlibrate your meter like this :

FRom a previous jakob's post

Put in a signal, threshold at max (no gain reduction)

Adjust output level to 0dB (or 1V AC)

Turn threshold downwards untill level drops to -6dB (or ½V AC)

Check that your meter reads 6dB GR.

If it reads more, use larger series resistor.

If it reads less, use smaller series resistor.

You could possibly use a trimmer in series with the meter for final finetuning.

Don't expect the dB scale on the B* meter to show anything linear - it's some homebrew scale. You need a linear meter with a linear scale to read accurately.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mathflan on March 16, 2006, 09:15:04 AM
HI,

My SSL worked good some days ago but Now I have a big trouble on It.

In fact I put a 0db signal 1Khz into the SSL so as to See how that THe SSL threat the signal.

with the SSL bypass , I have 0dB, GOOD.

I turn the THRESHOLD at 0, so NO compression, with Make up at 0.


I read

RATIO 2:1

- 24,5 dB

RATIO 4:1

- 31,5

RATIO 10:1

-34

with Make up at MAX,+20.

I read


RATIO 2:1

- 8,2 dB

RATIO 4:1

- 15,2

RATIO 10:1

-17,6


Before, When I turn the threshold to have a defeat of -10db for example, I could Recover the volume with the make up, now I can't...
SO I don't think It's good, do You know What can I check on the board to find the trouble?

thanks
Title: SSL HELP THREAD!!!
Post by: 5meo-geo on March 16, 2006, 10:16:22 AM
10x man
it was easy one :D
Title: part number for vca ic socket
Post by: Dor on March 18, 2006, 08:31:23 PM
hello, would someone be so kind as to post the part number for the IC socket for the vcas? I ordered from the PDF but am missing the correct part # for this particular socket

Thanks in advance!

D
Title: SSL HELP THREAD!!!
Post by: BladeSG on March 19, 2006, 05:21:32 AM
I don't know if there is a correct part for this. You can cut a 16 pin IC socket in half or just cut down some IC socket strips like this:

(http://www.eleparts.co.kr/imall/item_images/2853.jpg)
Title: SSL HELP THREAD!!!
Post by: fucanay on March 19, 2006, 08:58:49 PM
I just got my second GSSL up and running last night and there is something very screwing going on. I've read all 100 pages of this thread today and one person asked about the same thing, but it just died there.

What's happening is the meter goes crazy when the threshold pot is turned. I've compared everything with the first unit I built and everything is the same except the voltages I'm getting on the TL072 and TL074.

Here is what I'm getting:

First Unit
----------
TL072
1. -3.06 through +3.08 when thresh is turned
2. 0
3. 0
4. -12.16
5. 0
6. 0
7. 0 through -1.95 when thresh is turned
8. 12.17

Second Unit
----------
TL072
1. -3.06 through +3.10 when thresh is turned
2. 0
3. 0
4. -12.26
5. 0
6. 0
7. 0 through -1.95 when thresh is turned and voltages go crazy when thresh is turned
8. 12.20

First Unit
----------
TL074
1. -.10 through .19 when thresh is turned
2. 0
3. 0
4. 12.17
5. 0
6. 0
7. 0
8. 0
9. 0
10. 0
11. -12.15
12. 0
13. 0
14. .38

Second Unit
----------
TL074
1. .21 and spike wildly when thresh is turned
2. 0
3. 0
4. 12.20
5. 0
6. 0
7. 0
8. 0
9. 0
10. 0
11. -12.26
12. 0
13. 0
14. .14 and spike wildly when thresh is turned

What I've done so far is to change all of the chips in that area (072/074/2181LB), compared and traced wiring on both units and changed the voltage regulators. None of this helped. I also went back and searched for solder bridges and check the wires going to and from the front panel PCB.

I feel like the problem is right under my nose, but I'm lost at this point.

Any ideas?

Matt
Title: SSL HELP THREAD!!!
Post by: fucanay on March 20, 2006, 02:36:23 AM
This is becoming a habit for me in this thread. I figured the problem out before anyone had the chance to help. It was the standard problem of "check for solder bridges"! I found one in a place I didn't expect and it fixed everything. It was between pins 5 and 6 on the 5534 in one of the emulation circuits. If anyone else has this problem, this might be a place to check. I found it when I discovered that the chip was getting a little bit warmer than the other one.

So thanks to Jakobs standard reply, I found the issue. Is it me or is trouble shooting fun when you actually find the problem?

Thanks Again

Matt
Title: SSL HELP THREAD!!!
Post by: fenderfred on March 20, 2006, 11:42:27 AM
Hello!
I need some help
I can't get +15v out of 7815

on power section:
7915  : in-22.8v / out -14.9v (good)
7815  : in 22.5v / out -0.06v (???)
78L12: in 22.3v / out 11.9v  (good)
79L12: in -22.7v / out -11.9v good)

i used reg TS7815 that i replaced with a new one but no change (-0.06v)

i'm going mad!!!
Title: SSL HELP THREAD!!!
Post by: fenderfred on March 20, 2006, 11:49:32 AM
Sorry !
not -0.06v but -0.6v
Title: SSL HELP THREAD!!!
Post by: gyraf on March 20, 2006, 12:49:59 PM
As always, look for the shorts..
Title: SSL HELP THREAD!!!
Post by: Greg on March 20, 2006, 01:22:21 PM
Quote from: "fucanay"
Is it me or is trouble shooting fun when you actually find the problem?

I'd have to disagree with you on this one. I think troubleshooting is a royal pain in the ass. Just today I was checking a PLC panel and found a short at one of the breakers...  :roll:  Took me two hours to find the problem. But fixing things is always rewarding, so I'd agree with you there  :thumb: .
Title: SSL HELP THREAD!!!
Post by: OffChip on March 20, 2006, 01:27:31 PM
Hi,

I need some advice for my SSL clone.
I bought a 1U schroff rack case, and I noticed the useable height of the case is only about 34mm. The power transformer I bought has a height of 39mm, so obviously it won't fit in the Schroff case.   :?
So I was looking for another transformer and found one from Farnell: 9532161. But I'm a bit confused because in the specs a bolt length of 40mm is mentioned. And this is larger than the height of my rack case.
Can somebody confirm it will fit in my box, because I don't want to risk buying another part which I can't use.

Thank you very much!
Title: SSL HELP THREAD!!!
Post by: fucanay on March 20, 2006, 01:28:38 PM
Quote from: "Greg"
Quote from: "fucanay"
Is it me or is trouble shooting fun when you actually find the problem?

I'd have to disagree with you on this one. I think troubleshooting is a royal pain in the ass. Just today I was checking a PLC panel and found a short at one of the breakers...  :roll:  Took me two hours to find the problem. But fixing things is always rewarding, so I'd agree with you there  :thumb: .


Don't get me wrong. I would prefer to have everything work on first power up, but I also wouldn't be learning anything. I've only been at this a couple of months and this time period is critical to learning to read schematics and trace components on the boards. Every little error corrected is a new thing learned. Very exciting to me.

Someday, I would like to be able to look at a schematic and build something, so this trouble shooting is very useful to my overall knowledge.

Matt
Title: SSL HELP THREAD!!!
Post by: fenderfred on March 20, 2006, 02:12:15 PM
Thanks Gyraf
I'm looking for...
I read a topic where you talk about problems you had with 78XX.
Mine are marked TS7815-5C4CZ.
Do you believe they're in fault?
Title: SSL HELP THREAD!!!
Post by: Ozzie on March 20, 2006, 03:33:39 PM
Hi!
I finished putting together my first GSSL two weeks ago, but ran into problems...
First, it was a faulty VCA (2159's from a behringer ultramix, I guess I "cooked" some while desoldering them with a heat gun). After solving that (and two shorts), I have another problem:

- I input a +6dBu (1.54V), 1kHz sine wave
- In bypass, I get appr. +11dBu (2.8V) on the output
- With Attack and Release set to Fast and Makeup to zero, the meter shows gain reduction while turning the Threshold.
- However, with Threshold fully turned I get these numbers:

Ratio 2 - GR 4.7dB (1.67V out)
Ratio 4 - GR 5.9dB (1.45V out)
Ratio 10 - GR 6.4dB (1.36V out)

It seems that it's not compressing "enough".
I also tried lowering the input to -25dBu (-19dBu out), and at Ratio 10 with the Threshold fully turned, it showed a GR of 3dB (-22dBu out).
Also, the Makeup pot only adds 1.5dB at any setting.

I have tried swapping the VCA's around with no change. The meter is slammed to the right while the Threshold is fully turned, but it's not really calibrated (300uA meter with a 6.7k resistor in series instead of the 2k), so I guess it's not really trustworthy (5.6V at the meter terminals without the meter hooked up).

My voltages all seem ok.

Does anyone have any idea as to what the problem might be?
Grateful for any help I can get!
Title: SSL HELP THREAD!!!
Post by: udenjoe on March 20, 2006, 05:15:38 PM
Quote from: "Ian MacGregor"
Carbon resistors are fine. 5% is probably just fine as well. I would, however, buy 1/4 watt resistors and NOT 1/2 watt resistors. The PCB layout is a little cramped as it is.
Ian


Well, I finally found the question, page 26.  How about an index?  Anyway... :wink:

Ok, I bought some 1/2w 1% resistors from Mouser.  I didn't order them all, just about $20 worth I could afford.  I needed some to finish my Mini Synth.

Would it be ok to use the ones I got 1/2w while ordering 1/4w, to fit better?  How about mixing tolerances?  Does it really matter if or what you mix (wattage and tolerance of course) the resistors in the GSSL?  If carbon is fine can you mix in metal too?
Title: SSL HELP THREAD!!!
Post by: gyraf on March 21, 2006, 04:13:21 AM
..the ssl is happy with just about any resistor you can fit on the pcb's..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: gyraf on March 21, 2006, 04:15:42 AM
Quote from: "fenderfred"
I read a topic where you talk about problems you had with 78XX. Mine are marked TS7815-5C4CZ. Do you believe they're in fault?


Maybe.

Stay away from the regulators marked "TSxx". I don't know what the brand is, but I've had MANY problems with these - latching up, going bad etc..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Dor on March 23, 2006, 11:43:46 AM
Quote from: "RogerFoote"
They are called SIP sockets. I think Greg's 1176 BOM has a number for them if you don't want to cut down a DIP socket.


Thanks!
Title: SSL HELP THREAD!!!
Post by: Purusha on March 24, 2006, 10:25:28 AM
Hey Greg,

which (Nichicon) capacitors are kinda important for better sound? Those six 22u and four 100u on the bottom of the SSL schematics?
Title: SSL HELP THREAD!!!
Post by: BR on March 24, 2006, 11:19:21 AM
Hey Ozzie,


Quote
- In bypass, I get appr. +11dBu (2.8V) on the output

Looks like you have about 6dBs of gain on the outputs.  Just replace the 15K resistors right after the VCAs for 27K,  or a 50k trim pot and adjust for unity gain output.  This has been talked a lot in here.  Do a search or use the meta and you will find tons more info on this.

As far as your ratios.  Find the Ratio measurements thread on the SSL Clone meta and it will take you thru all the proper steps for measuring and also a few adjustments on some resistors.

Hey Purusha


Quote
which (Nichicon) capacitors are kinda important for better sound? Those six 22u and four 100u on the bottom of the SSL schematics?


Yeah, basically the 22u and 100u on the Input and Output section of the pcb.   I just put some Black Gates on mine but havent tested yet.   I also have one with Nichicons, so I'll probably run a comparison.

peace
Gil
Title: SSL HELP THREAD!!!
Post by: Greg on March 24, 2006, 11:24:04 AM
I like the Nichicon PW. I think they're also called UPW by some.

The ones at the bottom of the schematic are for the PSU, so those aren't the most critical. Also, the ones at the bottom are 100n, not 100u. The most important ones are in the signal path (ie the top two rows of the schematic). I believe it's 6-22u and 4-100u (as you stated).
Title: SSL HELP THREAD!!!
Post by: Purusha on March 24, 2006, 11:28:27 AM
Thanks.

I bought tons of Jamicon caps for all G-SSLs I am making, but will buy some Nichicon and make a comparison when first two are finished and over the troubleshooting phase  :green:
Title: SSL HELP THREAD!!!
Post by: Purusha on March 24, 2006, 03:35:17 PM
Just powered up my first out of eight G-SSLs and everything blow up   :shock:

just joking :green: it fired up from the first take, the voltage looks right :

+15,09
- 14,95  

+12,32
- 11,95

I am going to solder the ins and outs to test the sound and meter. Wish me luck  :thumb:
Title: SSL HELP THREAD!!!
Post by: fucanay on March 24, 2006, 06:19:40 PM
I've already powered up 2 GSSLs and they sound great. But I just noticed that I missed a jumper on both of them. It's the one that is right behind the 7815/7915 regulators. When look at the board it looks like this jumper would create a ground loop, but I'm not so arrogant to say that it shouldn't be there. So here I am asking what it's for and should I take them apart and add this jumper? I'm building another one right now and I'll put it in on this one, but I'd still like to know what it's for.

Thanks

Matt
Title: SSL HELP THREAD!!!
Post by: Purusha on March 24, 2006, 08:17:35 PM
OK. Some adjustments are to be taken care.

The sound is coming through, but it's not calibrated properly yet. There is absolutely no noise or hum even not being mounted in the box which is good.

I am using the 2181LB and have done these changes so far :

 - took out the 68R next to VCAs
 - replaced the 10K with the jumper next to the VCAs
 - replaced the 1M resistor with the 220K

For the meter I am using the 1K - 10dB scale. The meter works but didn't measure the accuracy yet.

I know I have to read the threads about taming the threshold and ratio adjustments but here is what I get out from my unit if you wanna give me some hints:

 - threshold is too much sensitive
 - I get distortion very easily when compressing the sound
 - the release works strange, 0.1s works fine, but auto position is distorting the sound, any ideas why?

If there is any G-SSL owner with 2181LB please let me know what where your calibration adjustments so I don't have to reinvent the invented :thumb:

The voltage regulators are also hot so I can't hold them with my fingers for long, is this normal?
Title: SSL HELP THREAD!!!
Post by: Purusha on March 24, 2006, 10:01:50 PM
OK, changed so far:

 - took out the 68R next to VCAs

 - replaced the 10K with the jumper next to the VCAs

 - replaced the 1M resistor with the 220K

 - replaced the 100K to 120K on the right of the TL074

 - replaced the 100R with 51R right of the TL072

 - replaced the 47K summing to 120K

 - soldered the 47K to the +leg of the threshold pot

RESULTS:

Less sensitive threshold but still getting distortion on 6dB GR
strange attack and release behavior, faster release shows more GR but less distortion than slower release, usually is the way around.

Anyway, threshold 12 o'clock, still reading 10dB GR....

At this moment I don't know what else to try, I just raised my hands hoping to get some mercy from the Lord soon  :roll:
Title: SSL HELP THREAD!!!
Post by: drummerman15 on March 25, 2006, 03:34:05 AM
Just finished populating the board and making all the conections - powered it up and checked voltages and everything was getting power in the right place.  I put the 2181's in to try and pass some signal and the left vca got real hot real quick - the right side and sidechain are fine.  I've checked and double checked for bridges and misplaced components but everything seems fine.  I haven't made the modifications to the dist trim section yet.  Any ideas what may be causing this or where to look.
Title: SSL HELP THREAD!!!
Post by: Purusha on March 25, 2006, 07:11:22 AM
I decided to move my calibration and troubleshooting phase of my G-SSLs from the SSL HELP thread because it's getting too big and it's hard to find something precise when needed.

If you have any suggestions please don't hesitate http://www.groupdiy.com/index.php?topic=169277#169277
Title: SSL HELP THREAD!!!
Post by: mathflan on March 25, 2006, 10:37:46 AM
Noone to help me for my trouble  :oops:

Quote
HI,

My SSL worked good some days ago but Now I have a big trouble on It.

In fact I put a 0db signal 1Khz into the SSL so as to See how that THe SSL threat the signal.

with the SSL bypass , I have 0dB, GOOD.

I turn the THRESHOLD at 0, so NO compression, with Make up at 0.


I read

RATIO 2:1

- 24,5 dB

RATIO 4:1

- 31,5

RATIO 10:1

-34

with Make up at MAX,+20.

I read


RATIO 2:1

- 8,2 dB

RATIO 4:1

- 15,2

RATIO 10:1

-17,6


Before, When I turn the threshold to have a defeat of -10db for example, I could Recover the volume with the make up, now I can't...
SO I don't think It's good, do You know What can I check on the board to find the trouble?

thanks
Title: SSL HELP THREAD!!!
Post by: fenderfred on March 26, 2006, 05:46:03 AM
Quote
fenderfred wrote:
I read a topic where you talk about problems you had with 78XX. Mine are marked TS7815-5C4CZ. Do you believe they're in fault?

Gyraf wrote:
Maybe.

Stay away from the regulators marked "TSxx". I don't know what the brand is, but I've had MANY problems with these - latching up, going bad etc..



Finally, i had find how to get +15v out of this (f---in') reg TS7815.
Simply by putting a second (the same TS7815) in //.
I must exhaust my stock !!!
Now my comp works very well...

Thus if you cross this brand of reg "Taiwan SemiConductor - TSC", flee!
or couple them :grin:
[/quote]
Title: SSL HELP THREAD!!!
Post by: rrs on March 26, 2006, 10:57:50 PM
Hi all
Have finisherd my GSSL a while ago now but have been making component changes along the way.

My most recent was swapping my NE5534's for burr brown OPA604.

To me these are just what i'd been looking for.

One problem though has occurred with this change in that I now get a low level high frequency squeal which sweeps from high to low frequencys.I notice this when I change settings or after playing audio with high compression mostly.

Any ideas on how to get rid of this.

I still have all the original value components and am using the pre trimmend That VCA's 2180.
Title: SSL HELP THREAD!!!
Post by: rrs on March 27, 2006, 12:54:43 AM
Thanks Rodger will try.Will get back to you in about a week when I get a chance to try it..

I am realy liking it though.Have run a few mixes through and gives a bit more spank (technical term). :thumb:
Title: SSL HELP THREAD!!!
Post by: mathflan on March 27, 2006, 04:12:37 AM
Ok my SSL works, I think the problem came from my audio card which had some troubles.

Just one question :

When I put THRESHOLD at +20 , MAX and MAKE UP at 0, the SSL when COmp is activate have 1dB more than When SSL is Bypass.
I test it with a 1Khz generator at -10db and -20db

Is it a SSL particularity or not??
Title: bypass switch
Post by: laus on March 27, 2006, 12:09:40 PM
Hello

A question about the control board : I really don't understand how to wire some pins, the A/A2/COM/C1 and C2 pins.
I only have a bypass switch (ON/OFF) with 3 contacts and the schematics shows a bypass with a Lorlin switch.
As I'm new in DIY, I ask you guys some help.

I think to wire a part off the bypass switch to A and the second part to A2 (I've understand that it defeat the makeup gain when the comp is out) , is this wiring correct?

Also, does the compressor work if the COM/C1/C2 pins are not connected?

Thanks a lot

Laus
Title: Re: bypass switch
Post by: sounden on March 28, 2006, 06:06:24 AM
Quote from: "laus"
Hello

A question about the control board : I really don't understand how to wire some pins, the A/A2/COM/C1 and C2 pins.
I only have a bypass switch (ON/OFF) with 3 contacts and the schematics shows a bypass with a Lorlin switch.
As I'm new in DIY, I ask you guys some help.

Thanks a lot

Laus


I´m having the same issue.
Title: SSL HELP THREAD!!!
Post by: Purusha on March 28, 2006, 10:58:28 AM
I think I got this one down :grin:

If you want to defeat the makeup gain when compressor is bypassed than you will need the switch with two rows of three pins. (double switch)

OK, now the middle pin on your switch would be C, the upper or lower pin would be C1 and the opposite pin would be C2. Very easy when you get it...  :green:

If you want to defeat the makeup gain than on the second row of pins connect the A to the middle pin and A2 to the pin which is next to C2 pin.

I hope this helps  :wink:
Title: SSL HELP THREAD!!!
Post by: laus on March 28, 2006, 02:40:56 PM
Thanks very much Purusha, I'm going to try this immediately.

I have another question about a bypass led : is it possible to have a bypass led which indicate the bypass model and if yes, how I can wire it??

Best
Laus
Title: SSL HELP THREAD!!!
Post by: Purusha on March 28, 2006, 03:00:25 PM
Yes it's possible but than you need triple switch (three rows of three pins). So the third row would turn the LED on and off.
Title: Sorted out
Post by: sounden on March 29, 2006, 04:34:23 PM
I think this would work?
I have toughts of steeling current from "Power ON" LED to bypass LED

3pol/2ways switch

OFF (NOT BYPASSED)
A-------o      o----A1--->(not connected)
C-------x----x----C1--->OFF (to PCB)
+LED---o     o----LED-- (not connected)

ON (BYASSED)
A------x-----x------A2 (connected bypass gain makeup)
C------x----x------C2--->ON (to PCB)
+LED--x----x-------LED--> (to PCB)

Do you think I got it right?

This topic helped me alot to understand the lorlin functions
http://www.groupdiy.com/index.php?topic=12627&highlight=lorlin+switch
Title: SSL HELP THREAD!!!
Post by: Purusha on March 29, 2006, 05:49:50 PM
Why don't you make a drawing of all connections in Corel or Photoshop? I don't know about others but I am not sure if I understood your explanation. It might be OK.
Title: switch bypass
Post by: sounden on March 30, 2006, 08:37:15 AM
Ok! Hopefully I explain myself enough now =)

(http://www.sounden.se/slask/bypass_switch.jpg)

Regards
Title: SSL HELP THREAD!!!
Post by: Purusha on March 30, 2006, 08:52:05 AM
It looks OK.  :thumb:
Title: SSL HELP THREAD!!!
Post by: sounden on March 30, 2006, 09:01:49 AM
Nice! then I will try this as soon as I get my last components.
Title: SSL HELP THREAD!!!
Post by: laus on March 31, 2006, 08:42:05 AM
Hello
The SSL clone works fine (thanks Purusha) but I have a "hum problem".
I already read the thread and wire my inputs to the case ( and I also try outout but nothing change), my IEC to the case and try to move the toroid transformer but nothing change.
I don't think the hum comes from the input because it still here with no input.
Therefore, the hum grown up when I put my finger on the 22µF caps near the inputs.
No ideas
If anyone can help me it would be great

thanks a lot

Laus
Title: SSL HELP THREAD!!!
Post by: Purusha on March 31, 2006, 01:21:39 PM
Sorry can't help you with the hum problem. My first tested G-SSL works fine although it's still outside the chassis.
Title: HUM problem too...
Post by: DQ on April 01, 2006, 12:21:20 PM
Hello ..

first of all i want to thank jacob, gustav and everyone else in the forum.
I have built my GSSL and it's my first DIY project and it's sounds great!!

I have a couple of issues I should solve though..

I have a HUM problem on both channel (altough LEFT ch is noisier).
I have not totally assembled the GSSL but i have placed it in the rack case and done al the grounding (at least i think so..:))
I have checked the bridge rectifier output and it gives me +19.02 and -19.13. The recitfier is W08M


The output of the regulators are:
+14.77
-14.81
+11.99
-11.99

I have noticed that if i connect togheter  pin1 of the XLR input to the other PIN1 the noise come down a bit.
I tried to move the toroidal transfrmer but nothing change. BTW I have a 2x15V 30VA

I also noticed that if i switch off the unit and turn it back on sometimes the compression doesnt work , toghter with the LED. If i wait a bit and turn it on again it works fine.

I hope someone can give me some advice and suggestions..:)

Many thanks..
Title: SSL HELP THREAD!!!
Post by: Pri on April 02, 2006, 03:25:25 PM
Hi,
well i thought i had it all running fine, but i have 4dB less output on the right channel (thought it was my mixer who wasn't working right).
I did some measurering and found out that i always have like 5,2 Volt on the negative output. Even without any signal passing   :?  .

But if i put a sine wave through i get like 3.9 Volts on the other outputs, but on the negative of the right channel it is still 5,2 Volts.. I don't have a clue what could be wrong 'cause besides that it is working right.

I made some slight changes but i had that problem before, so i don't think that they effected that problem (i change the 100k to 120k, and the 2k to 1,2K for the meter, and put 47k on the + leg of the threshold pot)

any things i should check??

Thanx in advance,
 Niklas
Title: SSL HELP THREAD!!!
Post by: Purusha on April 02, 2006, 03:32:20 PM
Swap opamps and VCAs, maybe you will get closer to the problem.
Title: SSL HELP THREAD!!!
Post by: Pri on April 02, 2006, 07:17:51 PM
yeah, should have tried that  :thumb:  .
That really was causing the difference. Thanx a lot...

By the way, what is difference between NE5532N/AN/AP?? I had Ns in there and now put some AP s in. I did not hear a difference (with a sinewave, though  :green:  )..
How do you guys know where to put the 0dB mark for the threshold on the front panel? How can I measure it (sorry if you had that question before, just ignore it).

Thanks again and good night

Niklas
Title: hum problem too...
Post by: DQ on April 03, 2006, 10:22:56 AM
Ok,

I found out the problem regarding the fact that sometimes the compressor doesnt work , It should be the 78L12 that sometimes get's stuck on - 0.7V or something like that..

I still have quie a lot of   hum (more on one channel) though..

does anyone have suggestions?....

Thanks!
Title: SSL HELP THREAD!!!
Post by: fucanay on April 04, 2006, 02:01:09 AM
I've been doing some testing on one of my SSLs and there seems to be a bit of noise and wanted to see what you guys think.

I took these screen captures in 3 different states with no audio passing through the unit.

1. SSL hooked up, but powered off. http://fucanay.fischerworks.com/diy/gssl/SSL_off.gif

2. SSL powered on, lowest makeup gain. http://fucanay.fischerworks.com/diy/gssl/SSL_in.gif

3. SSL powered on, max makeup gain. http://fucanay.fischerworks.com/diy/gssl/SSL_max_makeup.gif

I hear this noise and it kind of bothers me, but I'm not sure that it isn't normal. Any comments?

Matt
Title: still hum...sorry...:)
Post by: DQ on April 04, 2006, 04:20:59 PM
Hello again..

sorry for keep writing about the hum on my ssl , but i cant solve the problem.
It's quite loud , especially on the left channel.
I have read many old post about the problem and  have rewired all the grounds copying the same setup as Greg from an old post, I also tried with plastic spacers or isolating completely the PCB from teh chassis, but still no luck.
everything else seems to work just fine.

I noticed one thing though.
If i run a cable from the chassis to the ground positioned where the 1000uF condemsers are , the noise come down quite a lot but still there. If i run the same cable to the other side of the PCB's ground there's no change.
Yesterday running another extra cable i managed to bring the noise down a lot but unfortunately now that i assembled the machine i can't remember where that was..:))
I don't know , but to me it really seems there's some kind of ground loop, but i a total newbie and i am not experienced at all with this kind of troubleshooting..
As i said on the previous posts i chacked all the voltages at the various stages and seemed fine.

I hope someone can give some advice.....

thanks!
Title: SSL HELP THREAD!!!
Post by: Greg on April 04, 2006, 04:31:30 PM
DQ: Grounding issues are hard to troubleshoot via internet. Can you post a picture and I'll try and take a look to see if anything jumps out at me.
Title: SSL HELP THREAD!!!
Post by: DQ on April 04, 2006, 04:51:40 PM
Hi greg...:)

here's a pics..

http://www.unbearablerecordings.co.uk/z/sslwithhum.jpg

i put a note where the extra wire is..

I hope you get some ideas or suggestions...

thanks!!
Title: SSL HELP THREAD!!!
Post by: fucanay on April 04, 2006, 05:02:21 PM
The way the toroidal is hooked up seems strange to me. The way mine is, is that 2 wires are hooked together and they provide the 0V used as reference ground (i think). Do you have a datasheet for the transformer you used? Maybe it has something to do with that.

Matt
Title: SSL HELP THREAD!!!
Post by: Purusha on April 04, 2006, 05:22:02 PM
Maybe you should use the shielded cables from the PCB to the XLR connectors and not regular wires  :shock:

BTW I am using the same meter. Let me know it's accuracy when you are done with meter calibration. Mine does the job very well up to 6dB of GR, above that it goes off.

What VCAs are you using?
Title: SSL HELP THREAD!!!
Post by: DQ on April 04, 2006, 05:40:55 PM
in the meantime Thanks for your quick replies...:)

...The toroidal datasheet says:

Pri :white
Sec Yel 0V Green 15V - Yel 0V Green 15V

I dont know if i need to wire those togheter, they are connected on the PCB though. but I dont know really if that's ok.:)


Purusha: regarding shielded cables..how whould i connect them from the PCB. I didnt think i needed shielded for this!

regarding meter..i will let you know..I am still far from calibration for now..:)
I am using That 2180 LB. I have both 3 of 2180LA as well but i though i use the LB for now just in case burn them..eheh
Title: SSL HELP THREAD!!!
Post by: Purusha on April 04, 2006, 06:26:52 PM
Shield goes between 0 GND and XLR 1, red goes between + and XLR 2, yellow goes between - and XLR 3, you can solder some bridges between all IN and OUT XLR 1 pins and from there to the GND star.

red and yellow can be different color, depends on the cable manufacturer...
Title: SSL HELP THREAD!!!
Post by: fucanay on April 04, 2006, 07:00:29 PM
Quote from: "Purusha"
you can solder some bridges between all IN and OUT XLR 1 pins and from there to the GND star.



Depending on the jacks you use this may not always be ok. I used 1/4" metal Neutrik trs jacks on the ins and outs and thanks to Roger, I found that they were grounding as well as the wire connected to the star ground and was causing a loop. I won't be buying this type of jack in the future, but for now, I had to get some of those spikey start washers to get a really good ground from the jacks to the chassis and remove the wire going to star.

Matt
Title: SSL HELP THREAD!!!
Post by: Greg on April 04, 2006, 08:08:48 PM
Shielded cables aren't necessary for the GSSL. I've built 6 units without shielded cables and no hum problems. Let me take a closer look at the picture and see if I spot anything.
Title: SSL HELP THREAD!!!
Post by: DQ on April 05, 2006, 11:59:14 AM
Thanks everyone...

...unfortunately i dont think it's a matter of cables or connectors..at least for the amount of noise i am hearing..
..even when everything was just outside the case i had exactly the same noise..
I suppose once this is fixed i can have a closer look at the other details..

i wonder if it could be something with the PSU section...

...Greg .. i hope you see something..:)

ciao..!
Title: SSL HELP THREAD!!!
Post by: DQ on April 05, 2006, 02:49:52 PM
just an update..

I made a probe with te wire with the condenser/ resistor following an old post by gyraf.
I get a big hum (from the probe amplifier) touching the + of the rectifier. Is that normal?
Maybe it's a obvious question for most of you, but i really dont know..:))..and i am trying to find out where the problem is.

Thanks again..
Title: SSL HELP THREAD!!!
Post by: Greg on April 05, 2006, 03:25:29 PM
Still haven't had a chance to give it a good look. Soon, though.
Title: SSL HELP THREAD!!!
Post by: rbaker on April 06, 2006, 06:01:24 AM
I'm sure this has been asked before, but I couldn't find it in the 100 pages... I know that I need to cut the 16 pin connector for the vcas, but does anyone have a good way of doing so? I already broke one in half.  :(
Title: SSL HELP THREAD!!!
Post by: Purusha on April 06, 2006, 06:49:51 AM
Quote from: "rbaker"
I'm sure this has been asked before, but I couldn't find it in the 100 pages... I know that I need to cut the 16 pin connector for the vcas, but does anyone have a good way of doing so? I already broke one in half.  :(


I used the olfa razer  :thumb:
Title: SSL HELP THREAD!!!
Post by: BladeSG on April 06, 2006, 07:30:36 AM
If you have a look at page 96 of this thread there is info on socket strips.
Title: hum...
Post by: DQ on April 06, 2006, 09:51:25 AM
Hello again everybody...

..I have uploaded an audio sample of what i get out of my GSSL (with input shorted).
Maybe this will help more undestand what's wrong...or maybe not..:))

http://www.unbearablerecordings.co.uk/ssl/SSL_HUM.wav

Thanks...
Title: SSL HELP THREAD!!!
Post by: DQ on April 06, 2006, 11:52:41 AM
Greg..

a positive update!

I have moved the trasformer and the W04 from the middle of the PCB to the edge of the PCB, near the 1000uF caps , on the other connector (the one that was supposed to be right..:)))
The noise has come down a lot , almost completely!..
....so . it seems that this was the main issue...is that normal?..
is there something else i should do maybe?...
in the meantime i will try and finish the case

...thanks ..
Title: SSL HELP THREAD!!!
Post by: Greg on April 06, 2006, 11:55:52 AM
Excellent news !!! I have always used that connector by the filter caps. You must have been creating a ground loop some kind of way. It's difficult to know exactly. I didn't see anything obvious from the photo, that's why I didn't reply.

Also, when racking, try to keep wires as short and as tidy as possible. Good work !!!  :thumb:
Title: SSL HELP THREAD!!!
Post by: DQ on April 06, 2006, 12:03:39 PM
....I will try and follow you advice..:)..

Thanks...do you think I should i use plastic spacers?..I havent found any around here...

ciao!
Title: SSL HELP THREAD!!!
Post by: Greg on April 06, 2006, 01:34:05 PM
To stand off the PCB? Try a general hardware store. They should have a ton of plastic spacers. That's what I do !!!
Title: SSL HELP THREAD!!!
Post by: Purusha on April 06, 2006, 01:38:47 PM
DQ

Did you put all your jumpers near the big electrolytics? Maybe this cosed the hum problem.

Greg,

I have a stupid question to ask you. What would happen if instead of bi-polar electrolytic caps one would use the normal two way WIMA caps? Let's say instead of all 100uF and 22uF caps. I don't know about their size but in theory, would the G-SSL still work like it should? Someone just told me that the bi-polar caps sound bad compared to the two way capacitors. Maybe he was just talking nonsense, I don't know...  :grin:
Title: SSL HELP THREAD!!!
Post by: Greg on April 06, 2006, 02:32:39 PM
It'd work in theory, but try and find a 100uF polyester/polypro cap. It'll be the size of a mouse and cost as much as a house (well not really). But lytics can cram high capacitance into small spaces... They're often use to block DC (which is what alot of the lytics are doing in the GSSL).

Regarding sound, I wouldn't say one is always better.  They're different, though. Capacitors in the signal path definitely do affect the sound (good or bad). Try it out and see, that's the best info I can give.

Regarding the GSSL, I wouldn't bother.
Title: SSL HELP THREAD!!!
Post by: mathflan on April 06, 2006, 04:04:48 PM
Hi,

I Already talk about my SSL trouble but Maybe you could tell me what to check??

When I set the threshold at max, so no compression and Make up at 0, My SSL when active has a lower volume than when SSL is bypass.
is it normal, I don't think so....

A suggestion?

I'll try to put a sample tomorrow, I  have near 6 dB of difference...
Title: SSL HELP THREAD!!!
Post by: Purusha on April 06, 2006, 05:14:48 PM
Quote from: "Greg"
It'd work in theory, but try and find a 100uF polyester/polypro cap. It'll be the size of a mouse and cost as much as a house (well not really). But lytics can cram high capacitance into small spaces... They're often use to block DC (which is what alot of the lytics are doing in the GSSL).

Regarding sound, I wouldn't say one is always better.  They're different, though. Capacitors in the signal path definitely do affect the sound (good or bad). Try it out and see, that's the best info I can give.

Regarding the GSSL, I wouldn't bother.


Thanks for the explanation Greg. I will just put some Wimas and Nichicons like you did.

Can you tell me where do you order the Nichicons in USA? I have a friend from USA who will visit me in July so he could bring a few.
Title: SSL HELP THREAD!!!
Post by: Greg on April 06, 2006, 06:39:24 PM
Mouser or Digikey... The exact part numbers are in my parts list. Find that thread I started that has all my parts list. It's in there.
Title: SSL HELP THREAD!!!
Post by: Greg on April 07, 2006, 11:14:08 AM
mathflan: Are you measuring output between + and -, or between + and ground?
Title: SSL HELP THREAD!!!
Post by: Purusha on April 07, 2006, 12:38:48 PM
I have a question regarding my LEDs. I have to put two more and don't know what resistor to use. I bought most regular blue and red LEDs which I plan to connect after my extra 7812 regulator which I am using for feeding the true bypass relays. Can someone help me with this?

How should I connect the LEDs - in parallel or one after another and where do I put the resistance, before or after... ?


Quote
Mouser or Digikey... The exact part numbers are in my parts list. Find that thread I started that has all my parts list. It's in there.



Thanks.
Title: SSL HELP THREAD!!!
Post by: mathflan on April 07, 2006, 02:33:58 PM
Quote
mathflan: Are you measuring output between + and -, or between + and ground?


In fact, I didn't test voltage, just with My ears and vu meter on Nuendo.
Title: SSL HELP THREAD!!!
Post by: Purusha on April 08, 2006, 04:09:42 AM
No one knows what type of resistor goes with normal LEDs and 12V? I am sure this must be a piece of cake for all you experts here  :grin:
Title: SSL HELP THREAD!!!
Post by: Purusha on April 08, 2006, 04:51:06 AM
Don't bother, I just found out.

It's between 600-800 Ohms. 470 Ohms would be also OK if you like bright LEDs  :grin:
Title: SSL HELP THREAD!!!
Post by: DQ on April 08, 2006, 11:44:37 AM
just though i give another update regarding my gssl and hum issues...

..there still was some hum even after i moved the powersupply connection.
I dont know why , but i found out that if i connect the ground  near the sidechain to the ground on te chassis ,(probably i think another ground loop) the noise disappears almost completely, considering that i was testing with 20 dB of make-up gain and my desk control room at maximum level.
Maybe i still had some ground loops, whi knows..but I am happy that it sounds better! :)..

also i noticed that noise come down even moreif i disconnect the earth from the ground, maybe due to my poor earthing system in my house..

,,,ciao..and thanks for the various suggestions..
Title: LED
Post by: sounden on April 10, 2006, 05:35:36 AM
Hello!
When I connect my "Power ON" LED the current drops from ~+12V to
~+6V, Is this the way it should be?


~ means in this case, about...
Title: What does this mean?
Post by: muffy1975 on April 13, 2006, 08:16:34 AM
HI there,

I already completed my first project the 1176 without a hitch. MNATS Site guided me through and I it worked straight out of the box. Thanks GYRAF...alot for a great little design. It sounds cool along side my real LA2A and etc etc. So happy.

Ok so lets do the SSL. Its done. Voltages all good at the rails with out ICS (but a little high on one side of the 15V...thats normal until you load the ICS). ICS loaded the Voltages are good enough...15.3V on one side/15.04-V on the other. The 12 volt rails are even better. Both around 12.04 +/-.

Audio goes through the unit in BYpasss. The LED even comes on.
Switch in the compressor and I have no real gain control and the threshold is odd.

Now I've read all 100 pages and my sort of problem has come  up and is never answered. The reason surely is cos the answer is either blowing in the wind or there's a solder blob/a short somewhere or a wrong component somewhere. Cool. I'm learning alot.

Here's my first question?

What does -2.4V on PIN 5 of Sidechain VCA mean if that VCA is a 2150 and the main VCA are 2180LA's (and I have not attached the trim pots to these)?

Is there a link to hooking up the threhold/gain pot. I've followed the component layout chart exactly. No questions. Am I missing something here?

Thanks for any help. In the mean time I will keep looking for the answer in all the threads. Its got to be there somewhere right?

Michael de A
Title: SSL HELP THREAD!!!
Post by: muffy1975 on April 13, 2006, 08:31:39 AM
Hi there again,

I've checked continuity the 10 wired between the main PCB and the  control PCB. It's good.

With regard my problem in the last post which of these don't you like and could they be causing a problem?

1. I don't won't a meter telling be what I can hear. Theres no meter on my project. I've just left out. No jumpers no nothing.

2. the 4148s are the 200mA/100 v type.

3.The 6.8 tantulum is the 35V variety not the 50V.

I'll come back with some more things

Thanks everybody

Michael de A
Title: My guess is...
Post by: muffy1975 on April 13, 2006, 08:35:49 AM
Hello there,

my guess is that one of 3 three things are wrong

1. Dodgy TL074. Thanks Mouser...
2. Dodgy TL072. Thanks Mouser
3. Broken sidechain VCA.

What would you say?

Thanks everybody

Michael de A
Title: SSL HELP THREAD!!!
Post by: rbaker on April 13, 2006, 07:08:28 PM
I know this has been talked about before but I'm having a little trouble finding what I'm looking for...

I'm about to solder the lorin switches to the pcb and I don't want to do them backwards.  I know that they will work either direction, but I have "D" shafts and I don't want to have to unsolder them later in order to make the knobs point in the right direction.  I haven't bought knobs yet---so there is no way to tell.

Or, does it REALLY depend on what kind of knobs I get?

Thanks for the help....(sorry, my first diy project)
Title: SSL HELP THREAD!!!
Post by: Twin-x on April 14, 2006, 03:21:24 PM
Quote from: "BR"
Hey there guys,
I just asked Greg for some personal help with some problems I'm having with 2 SSL clones I'm building,  since I was afraid of sounding really dumb on the forum.   But since, I can really hide it anyways, I thought I should ask here too.  Maybe others with similar problems can benefit..

I have 2 units but I'm only going to describe one at the moment.

I have no way to do audio testing at home, so I just decided to start with power and this is what I found:..

7815   23.7V In  and 14.7V Out
7915  -23.6V In and -14.9V Out

78L12  23.5V In and 12.2V Out
79L12  -23.5V In and 12.0V Out

I basically comcluded that my power rails are fine with regulators working correctly.

I moved on to checking power at the ICs (with chips in sockets)  and this is what I got:

5534  Left input
Pin4   -14.97V
Pin7   14.78V

5534 Right input
Pin4   -14.97V
Pin7   14.77V

5532 Left out
Pin4   -14.97V
Pin8   14.77V

5532 Right out
Pin4   -14.97V
Pin8   14.77V

So I guess it is safe to assume that everything is going fine up to there.  

TL072
Pin4   -12.07V
Pin8   12.21V

TL074
Pin4   12.22V
Pin11 -12.07V

I guess everything fine here too..

Time for sidechain VCA

Pin5  -8.62V  (?)
Pin7  12.22V

So I figured there is something funky between the output of my 79L12 and the SC VCA but I couldn't find anything... hang on,  I'll take another look..
So, by looking at the schem and pcb, I noticed the 3k9 resistor in series with Pin5 of the VCA.  That could be what is causing the voltage drop, right?  if so, then this reading is correct, right??


I went on to measure the Voltage points that are labeled on the pcb, just to see if everything was OK and poked around and remember something about the Voltage labels on the bottom of the unit not being exactly next to the voltage points.  So I measured around on the spots that I thought should be read and they all seem fine.

I guess my questions,  after this long description,  is the -8.6V on the SC VCA any concern?  and is there anything else, power wise, that I should check for??

maybe some DC on the other pins of the chips or anything like that?

WOW.. I just learned so much doing this... this is great.


Thanks a bunch

Gil


I have these exact measurements (well maybe  afew millivolt diffrence.
Also i am in the same situation i cannot test audio because of missing cables.

The problem i have (not sure) is that when i switch on the unit the meter directly goes to the max. Is this normal? If i do bypass the meter drops.

If i leave out the 074 the meter stays at 0
If i leave out the 072 the meter goes slowly to max

Could someone get me on the right track?

thank,
jef
Title: D shafts and Control Panel Wierdness
Post by: muffy1975 on April 15, 2006, 05:56:51 PM
Hi,

I'm sure I read earlier that the D Shaft orientation question is not a problem if you get the knobs with hefty side screws (like Maplin ones) before you solder in your lorlins. You'll know then what options you have.

BR...did you post your question again or has someone posted it again because there wasn't an answer to it. Funnily enough.... I printed out this exact posting only!........out of 104 big pages of thread. I'm sure no one gave an ideas.

Anyway I've made some progress and some regression since last time.

My first problem was that the 12V +/- going to the control was being interupted by some evil cable between control panel and main PCB. Evil meaning snapped in secret.

Now I have gain control. Cool. But I need some compression and at the moment I'm just feeling mild depression.

 My LED has died and the threshold is kicking around wildly when turned. Maybe the LED is shorting something.I've taken a trip to Gomorra for a few days of relaxation. When I get home the LED's coming out and I'm checking my diode situation. One of them near the 74 is giving me a strange vibe. The diode tester gives me a reading in both directions. When the diode is tested away from the PCB its fine ie it tests in one direction only. So there is something wrong if it tests both ways. Maybe not the diode....the caps near by?????

Ok one hour later 500 miles from the my PCB and my home I've decided to call a bloody repair man who knows what the hell he's doing (...I don't...thought I did building my killer G1176) and give him what ever money he wants to fix the F****** thing. If I spend another day soldering and re soldering stuff and then breaking stuff that did work and destroying stuff that never worked I'll puke.

Oh and when it's working I'll tell you what was wrong and not just say.....its working...see ya.


Lots of love (in a human way)

Michael de A
Title: SSL HELP THREAD!!!
Post by: nicodjhouse on April 16, 2006, 07:19:18 AM
Hi guys !

I finished yesterday my compressor, perfectly working!
I wanna thank one more time Jakob for his wnderful gyraf website, and Roland Klinkenberg for his help

tell me how add photos and i'll update the post!
Title: SSL HELP THREAD!!!
Post by: Purusha on April 16, 2006, 07:38:43 AM
you have to upload them somewhere else and write down the link while using the "img" option inside edit window.

Tell us more about which VCAs did you use and what calibration changes you followed to get the compressor working nicely.
Title: SSL HELP THREAD!!!
Post by: nicodjhouse on April 16, 2006, 09:32:34 AM
I used the 2181LA VCA's, they all work perfectly. For the moment I find the compression a little weak. I'll test it with friends tonight and decide if I have to update some components.

I'll have to change a few components concerning the meter that I find very sensitive (as you can read on the topic "how to calibrate the GSSL")
Title: SSL HELP THREAD!!!
Post by: Twin-x on April 17, 2006, 08:06:51 AM
bump on http://www.groupdiy.com/index.php?topic=174945#174945
Title: SSL HELP THREAD!!!
Post by: gyraf on April 17, 2006, 09:17:22 AM
Quote from: "Twin-x"
bump on http://www.groupdiy.com/index.php?topic=174945#174945


The VCA supply voltage is fed through a resistor, so it won't be full -12V (take a look at the schematic).

From a quick glance, it seems that your voltages are correct.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Twin-x on April 19, 2006, 02:42:47 PM
Quote from: "gyraf"
Quote from: "Twin-x"
bump on http://www.groupdiy.com/index.php?topic=174945#174945


The VCA supply voltage is fed through a resistor, so it won't be full -12V (take a look at the schematic).

From a quick glance, it seems that your voltages are correct.

Jakob E.


Ok after a while of tracking i found out that my 50K pots were logarithmic.
I changed them and now i am getting somewhere.

If the treshold pot is 0 my meter starts to bounch up and down.
If i set attack higher i get more and more hum.

If treshold gets 50% the sound is not audible but i hear popping sound. sometimes the sound comes trough.

I changed the pot 2 times and i have changed all the vca's.

O yeah and if the bypass switch is turned on i get incredible hum.

I have the sidechain attached.

So any more help would be really appreciated
Title: SSL HELP THREAD!!!
Post by: gyraf on April 20, 2006, 04:13:17 AM
Hi Twin,

Start out without the sidechain filter, just to exclude problems there.

Check proper powersupply voltages.

Check proper cabling - specially around your bypass switch!

To repeat myself, 99% of errors in this circuit is 1)solder shorts. 2)wrong components or orientation. 3)wrong wireing.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mathflan on April 25, 2006, 05:23:31 AM
Hi

I have already asked this question, don't know if it's the right place but I need some advice od Good sound engineers..

I like to use my SSL comp for mastering but I'am hesitate the place where I have to  put the SSL ine the sidechain.

EQ PLUGS -> C4-.... -> SSL COMP

or

SSL COMP -> EQ -> C4....

What do you think about that??

thanks
Title: SSL HELP THREAD!!!
Post by: Purusha on April 25, 2006, 06:41:18 AM
I would go with the second order  :thumb:

...or maybe even the EQ in the beggining.
Title: SSL HELP THREAD!!!
Post by: mathflan on April 25, 2006, 07:05:02 AM
I'll try that...
Title: SSL HELP THREAD!!!
Post by: Greg on April 25, 2006, 08:12:45 AM
Generally, I'm a compression then EQ type of guy, but not always...
Title: SSL HELP THREAD!!!
Post by: mathflan on April 25, 2006, 09:40:10 AM
I will try to use this sidechain:

EQs->Multiband compressor->SSL->limiter.

BUt I'am afraid to compress a lot...

I'am worried too, because I will have to Re-digitalize the signal for use my SSL.
Title: SSL HELP THREAD!!!
Post by: gyraf on April 25, 2006, 10:37:56 AM
As this is an error-fixing thread (and big enough already as is), it'll probably be better to discuss uses of the clone in the Brewery..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: mathflan on April 25, 2006, 01:09:16 PM
yes, gyraf you 're right

 :shock:
Title: 12v for relay
Post by: suprughetto on May 01, 2006, 05:05:43 PM
Hi all,
just a quick question...I'm changing my ssl bypass from original version to hardwire bypass with relays, but i'm not sure where (or how) to get 12v DC for bypass relay?
I tried several solutions but i'm getting hum...I made a relay board using a test board (i had that one at home and it was faster ot do it;i saw people doing it that way). I think RoogerFoote is not using extra regulators on his boards. I tried to use an extra rectifire using just one secondary and 12v regulator to take it down to 12v...Bypass worked always but i keep getting hum. There is no hum in bypassed mode... I'm missing here something. Just a wiring problem, ground loops?
thanks
well i think i got it...there is still some hum with make up gain all the way up
Title: SSL HELP THREAD!!!
Post by: suprughetto on May 03, 2006, 10:10:49 AM
well, i fixed it; everything ok and working :grin:
Title: SSL HELP THREAD!!!
Post by: OffChip on May 03, 2006, 01:41:11 PM
Hello,

I'm debugging my SSL clone and I need some suggestions.
Here's what I  have done so far:
When I put a 1KHz 1Vptp  sine at the input, I measure a 1KHz 20Vptp square wave at the output. Moving the make-up gain pot, threshold pot, or bypass switch doesn't make a difference.
After several hours of IC swapping and measuring, I came to the conclusion the sidechain is causing the trouble. I discovered I could make a nice clean sine wave, instead of a square wave, appear at the output by removing the TLO74. I already tried replacing the TLO74, and I also measured the diodes, but it didn't solve the problem. Just to be sure I'm going to order some more TLO74's because I only had one spare left.
I don't know how this rectfier works exactly , so could anyone explain this to me. I'm especially interested to hear what the signal should look like on the different nodes of the rectifier.
I also welcome other suggestions.

Cheers!
R
Title: SSL HELP THREAD!!!
Post by: Greg on May 03, 2006, 03:24:40 PM
Double check for shorts around the TL074... or incorrect resistor values.
Title: SSL HELP THREAD!!!
Post by: gyraf on May 04, 2006, 02:20:00 AM
..and on the control board..
Title: SSL HELP THREAD!!!
Post by: OffChip on May 04, 2006, 06:52:51 AM
Thanks for the tips. I'll check it out as soon as I find some spare lab time.

Cheers,
R
Title: GSSL funny business driving me crazy!
Post by: dax on May 04, 2006, 06:02:06 PM
sorry to add to the length of this thread, i have all ready read it about 10 times through!!!

2 questions

1. i think my -15v rail is sorted to ground...It measures proper voltage but is reads shorted with the continuity checker on my dmm??
There are no soldering shorts and I have tried replacing most of the components associated with the rail...no change?

2. There is no ground path on part of the control pcb (relase and make-up as well as led and all of the .47u caps....etc) even when not connected to the main PCB? with power i measure 10.6v dc where it should lead to ground for example the LED negative terminal (oh yeah it lights up if i short it to ground??)
any thoughts... thanks in advance!
Title: SSL HELP THREAD!!!
Post by: Greg on May 04, 2006, 07:49:18 PM
Regarding your first question... measure actual resistance. If something really low like 0.2ohm shows up, that's a dead short. I don't like the continuity beepers in general.
Title: SSL HELP THREAD!!!
Post by: dax on May 04, 2006, 10:34:27 PM
thanks greg...
1. both rails read about 110kohms to  chassis ground
2. there was a a broken pad between Control 0 and the off from bypass.
Title: SSL HELP THREAD!!!
Post by: rbaker on May 07, 2006, 05:30:35 PM
So...I'm really sorry if this is really beginner of me, but I'm still trying to find the correct way to ground my ssl.  I'm done with everything but this...I've seen a lot of discussion on how to do it---but nothing that ever said which was was the best.  I understand I might need to make some changes (ie: trial and error) but how should I start?  The ground connector on my iec has nothing connected to it at this point.

I'm a little afraid to plug it in...this is pretty new to me.  :?
Title: SSL HELP THREAD!!!
Post by: Greg on May 07, 2006, 08:38:31 PM
Ground on IEC goes directly to chassis !!! Safety !

Also ground from pin 1's on the input XLRs to the chassis.

Measure from the rails to ground to make sure there aren't any shorts.

Then fire her up !  :thumb:
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 08, 2006, 12:10:17 AM
I need help building the SSL clone. I just ordered the PCB's from Denmark and finished them minus the 3 2150 units I am ordering. I need to know where to buy wires, where to hook up wires, rack, PSU etc. Can anyone help a new DIYer?

Thanks,
Adam
 :guinness:
Title: SSL HELP THREAD!!!
Post by: gyraf on May 08, 2006, 01:53:13 AM
Hi Adam,

Read through this thread - and through the SSL-clone threads referenced to by the "Meta-Meta" thread.

And read the page at Gyraf/diy.

And last, read the thread "META - Electronics 101 - By CJ"

That should do.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 08, 2006, 12:25:40 PM
Jakob, I tried to look for information on hooking up up the transformer but no luck. Maybe I am overseeing something. I am using a toroidal transformer but don't know which color cables go where on the PCB. Any links to threads would be greatly appreciated.

Adam
Title: SSL HELP THREAD!!!
Post by: rbaker on May 08, 2006, 01:14:53 PM
the colors depend on the transformer you have.  Look on page 4 of the ssl help thread.  The colors listed on there are for the amveco (I believe) which is what is in greg's part list.  A lot of us have been using avel lindberg because the amveco was on back order.

I copied greg's post and attempted to translate the colors for the avel lindberg, and here's what I came up with.  I could be wrong though---hopefully someone can double check this???


On the primaries:
Tie  BLUE and VIOLET together and that goes to your common  on jack it's "N"(not GND).
Tie GREY and BROWN and that goes to the hot (on jack, "L") (115VAC/120VAC).

On the secondaries:
Tie RED and ORANGE together...
Then measure between BLACK and YELLOW and you should have approximately 30VAC.

When you go to connect to the Main PCB, the RED/ORANGE (which are connected together), go to the middle point of the three. Connect Black to the outside and Yellow to the one on the inner part of the board.

Basically we're connecting the primaries is parallel and the secondaries in series.
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 09, 2006, 12:43:45 AM
I am using Kev's parts list and I have a transfo from Jaycar and it has 6 wires. I need to know where to solder them on the PCB and in which color sequence. Here is what the label reads:

IP: 0-240V 50hz    ORG-ORG
OP: 0-15V (0.67A)     0-15V(0.67A)
        YEL-RED              WHT-PUR


I am confused with "IP" and "OP" (however, I'm down 'wit OPP)

Any help is appreciated,

Adam
 :sam:  (This represents Newcastle for me)
Title: SSL HELP THREAD!!!
Post by: gyraf on May 09, 2006, 02:39:31 AM
IP - input - primary

OP - Output - secondary
Title: SSL HELP THREAD!!!
Post by: mnats on May 09, 2006, 03:27:07 AM
Quote
I am using Kev's parts list and I have a transfo from Jaycar and it has 6 wires...
IP: 0-240V 50hz    ORG-ORG
 :sam:  (This represents Newcastle for me)

You will probably have to hook it up to your clothes dryer outlet in Alabama - it's 240V only primary for most of Jaycar's toroid line. Many other toroidal power transformers (sold outside Australia) have dual primaries so you can wire them for 120V or 240V, but not from Jaycar aside from the encapsulated ones. For everything after the primary, Mark Burnley's wiring guide might help you: http://www.diyfactory.com/data/transformer_connections.gif

I'm a big fan of Newcastle Brown Ale too. So down a few pints and then give Jaycar a call and ask them why they would sell a 240V transformer to someone in the USA...:evil:

BTW the Jaycar encapsulated toroids don't come with suitable secondary voltages for the GSSL compressor. But over here Altronics has one that will work (http://www.altronics.com.au/index.asp?area=item&id=M4330). I used it in my GSSL and made a little PCB with a switch so it can be used with either 120 or 240V:
(http://img.photobucket.com/albums/v295/mnats/ssl_ps.jpg)
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 09, 2006, 09:26:08 AM
So let me get this straight...Input power (IP) are your primary wires that recieves power from a 110v source (here in the States) which is wired to the IEC inlet, and Output power (OP) are the secondary wires from the transformer to the PCB (+-15v). Well I'll be a sum'*****! :shock:

 :sam:  :sam:  :sam:  :sam:  :sam:  :sam:  :sam:  :sam:
Title: SSL HELP THREAD!!!
Post by: JRE Productions on May 09, 2006, 11:26:23 AM
Has anyone tried a standard transformer in this unit instead of a toroid? I have a few (1A) 14-0-14 transformer lying around. They appear to fit in a 1 U chassis. They look simular to the ones in UREI LA4a, or any of thier EQs.

I am assuming at 1A per secondary, it will have enough current to maintain the 15 v after the diodes/regulator ect. Am I right?  I think PPR said that the diodes create a multiplier of 1.4 of the input voltage.

Joe
Title: SSL HELP THREAD!!!
Post by: gyraf on May 09, 2006, 11:53:24 AM
Quote
Has anyone tried a standard transformer in this unit instead of a toroid?


Yes. Works well, as long as you don't have output transformers in the same box as well.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: JRE Productions on May 09, 2006, 03:41:41 PM
Thanks  :thumb:   I shall give it a try.

And hopefully I asked all my stupid questions on the G1176 post. I certainly learn a lot.

Joe
Title: SSL HELP THREAD!!!
Post by: rbaker on May 10, 2006, 11:44:45 PM
So I finally got around to firing up my ssl.  I flipped the switch and nothing happened.   I checked the fuse and it was done.  I put another one in and I saw the led (meter led that was added) light up and quickly go out.  I don't think the normal control pcb led ever lit up.  That fuse is now done as well.

meter led: I wasn't sure how to install that and I was a little shakey on the toroid, so I took it to my tech to do those 2 parts.  He used what I assume is the appropriate restistor?

Any idea where I should start?

 :sad:

I'm using .315 amp 250 volt gma fast acting fuses.

Edit: I was going to try taking out the extra led, which is attached to one of the regulators.  I noticed that I missed a jumper right by the regulators.  I added that, replaced the fuse and powered it up. It turned on and the meter led lit, and stayed on, the control led didn't.  After a minute, I turned it off and then tried to turn it on again and now it won't do anything anymore.  Do I need slo blow fuses or is it something else I screwed up?
Title: SSL HELP THREAD!!!
Post by: gyraf on May 11, 2006, 01:24:40 AM
Quote
I'm using .315 amp 250 volt gma fast acting fuses.


You always NEED a slow-blow ("T"-type) fuse for transformer primary protection - the start-up current will trigger any fast-acting type..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: rbaker on May 11, 2006, 03:23:47 AM
thanks jakob.  I found upon another problem while I was trying to search other things I'd missed.

78l12 and 79l12 were switched!  :oops:

I'm so mad at myself, I remember being extra careful with that (or so I thought)

If the fuse was burning because of the power up, do you think everything else is safe?  I'm going to put in new 78l12/79l12's just to be sure.
Title: SSL HELP THREAD!!!
Post by: gyraf on May 11, 2006, 03:27:56 AM
Quote
do you think everything else is safe?


I'd expect so..
Title: SSL HELP THREAD!!!
Post by: bugbrand on May 11, 2006, 05:07:03 AM
Joy-of-joys ---> plugged in the first of 2 SSL clones last night and all seems to be working spot-on straight off.!.

Wouldn't have been possible without all the aces-of-info around here.

Mighty thanks to Mr.Gyraf and all you others!

...

...

will try to finish the 2nd one off asap -- the 2nd will have proper 202 VCAs while the 1st has simple THAT2180s - will be interesting to compare them.
Title: SSL HELP THREAD!!!
Post by: gyraf on May 11, 2006, 05:28:07 AM
:thumb:  :thumb:  :thumb:
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 11, 2006, 09:47:39 PM
Quote
I copied greg's post and attempted to translate the colors for the avel lindberg, and here's what I came up with. I could be wrong though---hopefully someone can double check this???


On the primaries:
Tie BLUE and VIOLET together and that goes to your common on jack it's "N"(not GND).
Tie GREY and BROWN and that goes to the hot (on jack, "L") (115VAC/120VAC).

On the secondaries:
Tie RED and ORANGE together...
Then measure between BLACK and YELLOW and you should have approximately 30VAC.

When you go to connect to the Main PCB, the RED/ORANGE (which are connected together), go to the middle point of the three. Connect Black to the outside and Yellow to the one on the inner part of the board.

Basically we're connecting the primaries is parallel and the secondaries in series.


Okay, so I got an Avel Lindberg from Parts Express. I am about to wire it up and hopefully someone can back me up on this.

TIE TOGETHER:
Blue - 2x115v
Violet

TIE TOGETHER:
Gray - 2x115v
Brown

TIE TOGETHER:
Red - 15v
Orange - 0v

Black - 0v - To solder joint nearest corner of PCB
Yellow - 15v - To opposite solder joint nearest components
Red/Orange - To middle
Title: SSL HELP THREAD!!!
Post by: BR on May 12, 2006, 06:28:33 PM
All right.. my turn now..
I noticed the thread on 2181 mods but not on 2180 mods, so I thought I should ask some questions.

I just finished putting together another clone and this time I used 2180LA for main VCAs and 2181LB on the SC.

After looking at this design note from THAT
www.braudio.com/forumfiles/2180modref.pdf
I only saw a few things I should leave out of the emulation circuit.
I've circled them on this pdf.
www.braudio.com/forumfiles/2180mod1.pdf

Could anyone check and see if this is all I need to do?  I looks like it for me, but I could be overlooking something.

I powered the unit up without those components and I get nothing. (audio)
I also noticed the 5534 on the emulation section got really warm, and the voltage reading on pin 4 was something like 6V.  Which I thought was kind of strange.

Any ideas??

Thanks
Gil
Title: SSL HELP THREAD!!!
Post by: gyraf on May 13, 2006, 02:44:45 AM
Hi Gil,

I believe that we've covered most of those questions in this thread already?

btw, I've updated the ssl-page at gyraf/diy to cover 2180/2181 in simple terms.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: imo on May 13, 2006, 05:02:29 AM
Hello everyone.
I have a couple of stuffed SSL boards, minus the VCA's, until i am clear on everything.
I checked the power rails, and +15 is dead on, +12, and -12 are on as well. -15 is reading at -16.45 though. Both units are getting almost exactly the same readings on all including the "high" negative
I did some brwosing through the forums and found some info on power supplies where some folks were saying that the 79 series regulators could register hot until a proper load was put on them. This sounds like what is going on with my 2 units. I have not soldered in any of the jumpers yet, so the power is not seeing a proper load.
Just checking to see if this jibes with other's knowledge of who these guys work. It would be a bit wierd if both the regulators were off in exactly the same way<G>
Any thoughts?
Ian
Title: SSL HELP THREAD!!!
Post by: gyraf on May 13, 2006, 05:06:22 AM
Hi Ian,

As has been said before, you need to fully stuff the pcb's before trying to judge anything about the psu voltages..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: BR on May 13, 2006, 10:27:33 PM
Thanks Jakob,
I'll look it up on your site.
peace
Gil
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 16, 2006, 12:04:44 AM
I am getting 18.3 volts across the board on my PCB. When I fire up the unit, the meter red lines and stays there. It is obviously getting too much current. Any suggestions?
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 16, 2006, 12:40:22 AM
Okay I checked the voltage on my leads going to the board from the transformer. I'm getting 37 volts! And of course half of that is 18. 5 (which I am reading 18. 3 - 18.4) Why is this?
Title: SSL HELP THREAD!!!
Post by: 12afael on May 16, 2006, 12:52:35 AM
my unit don´t compress, audio pass ok.

the power supply voltages are OK.

the make up control work well , I have DC change on the threshold control , I have ac signal on point A but I can´t see nothing more on the rectifier circuit and time constants. I replace the TL074 and it is on the right position.

I have an old tube scope it only read AC. can I see the control voltage on the rest of the rectifier circuit and time constants?

the make up and threshold control just carry dc? if they work my problem is only the AC part?    

I have a meter from an old pioneer radio I don´t know if it read voltage or current , how can I know this? it don´t move but the problem in on the rectifier I think.

If I don´t use a meter should I left the wires open or short?
Title: SSL HELP THREAD!!!
Post by: 12afael on May 16, 2006, 01:55:50 AM
I fix it!!! :grin:  a thin imperfection on the board.

still I need info abou the meter

and of course thanx Jakob for the project!
Title: SSL HELP THREAD!!!
Post by: rbaker on May 16, 2006, 02:02:21 AM
I haven't been in here since my issues with the voltage regulators and the wrong fuses...

Anyway I switched the 78l12/79l12's out and put them in properly and picked up some slo blow fuses.

I measured all of my voltages and everything ran fine.  Took it down to the studio, fired it up and it works!  So far I can't tell that there's any hum and it's sounding awesome!

1 question, when I change the release settings, I can hear it in the audio.  I know that it shouldn't matter since I won't be changing these settings in a mix, but since it doesn't do that on the ratio or attack, I thought I'd ask.

Anyone know if this is normal or if I screwed something up?  Thanks for all the help.  When I started this I didn't have a clue what I was doing.   I'm about to start my 1176 and I think I'm hooked.  :grin:
Title: SSL HELP THREAD!!!
Post by: gyraf on May 16, 2006, 02:41:29 AM
Quote from: "rbaker"
1 question, when I change the release settings, I can hear it in the audio.  I know that it shouldn't matter since I won't be changing these settings in a mix, but since it doesn't do that on the ratio or attack, I thought I'd ask.

Anyone know if this is normal or if I screwed something up?  


Normal. If you look at the schematic, there's a perfectly logic reason for this.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Greg on May 16, 2006, 07:52:09 AM
Quote from: "bluezplaya"
Okay I checked the voltage on my leads going to the board from the transformer. I'm getting 37 volts! And of course half of that is 18. 5 (which I am reading 18. 3 - 18.4) Why is this?

Are you using a 15-0-15 or 18-0-18. I usually read in the high 17s with a 15VAC, especially if unloaded. As you load the transformer, it might drop a little. In general, this seems normal to me.
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 16, 2006, 11:06:45 AM
Quote
Are you using a 15-0-15 or 18-0-18. I usually read in the high 17s with a 15VAC, especially if unloaded. As you load the transformer, it might drop a little. In general, this seems normal to me.


Yes sir, this is an Avel Lindberg 15v toroidal from Parts Express. I wired it according to the help thread I believe from one of your posts.

Blue + Violet to "N"
Brown + Gray to "L"

Red + Orange to center hole on PCB
Black to outside hole nearest corner
Yellow to inside hole nearest 1000uf Cap

Am I wrong in wiring this?

whew! I need a Newcastle!  :sam:
Title: SSL HELP THREAD!!!
Post by: keefaz on May 16, 2006, 11:35:31 AM
Did you put some ICs in the circuit ?
With a 18-0-18 transformer, I used to see +20V and -19V without
any ICs connected. When I have put the ICs, the voltage has dropped
to normal (+15, -15)

[edit]
I just see that you get 37V, surelly a bad transformer connection,
maybe you should refer to the very detailed post about transformers
in this thread ?
Title: SSL HELP THREAD!!!
Post by: bluezplaya on May 16, 2006, 11:53:11 AM
This board is stuffed according to the parts layout and everything is in place (as far as I know). But I will check out the more detailed section on transformers.
Title: SSL first one!...works great except for 60hz hum
Post by: AudioguyII on May 18, 2006, 09:18:32 AM
Hi all,
First thanks for all the info on this thread. Couldn't have built this first one without you guys.

I am getting a hum at 63hz, a little less at 177hz,  and less at 300hz, it drops as it goes up the harmonics. Is this an AC problem?
 tried grounding different ways, no luck getting rid of it...
Any help would be appreciated.
I haven't racked it yet....this make a diffence?
Title: SSL HELP THREAD!!!
Post by: gyraf on May 18, 2006, 09:32:42 AM
Quote
I haven't racked it yet....this make a diffence?


Yes..
Title: SSL HELP THREAD!!!
Post by: Twin-x on May 18, 2006, 10:05:55 AM
Quote from: "gyraf"
Quote
I haven't racked it yet....this make a diffence?


Yes..


LOL  :thumb:

I had a hum too what i did was this: http://www.groupdiy.com/index.php?topic=180752#180752

Hum gone! Thanks Greg for telling this!!
Title: SSL HELP THREAD!!!
Post by: rbaker on May 18, 2006, 04:09:14 PM
I asked this before but nobody answered---I'm assuming it's because it's normal, but I'll ask again just to check.

When I change my release I can hear the clicking in the audio path, but not with the ratio or attack.  Can anyone else confirm that it's normal or did I screw something up?

Thanks again everyone.  I'll post some pictures when I figure out this lazertran thing.
Title: SSL HELP THREAD!!!
Post by: Greg on May 18, 2006, 04:15:42 PM
It's normal. No worries.
Title: SSL HELP THREAD!!!
Post by: AudioguyII on May 19, 2006, 11:24:21 PM
Thanks for the help... ran a bunch of extra ground wires and it brought the hum down. Next week I'll put it in it's chassis and hope for the best...
Sounds great though, better without the hum  :)
Title: SSL now racked!!! but now make-up gain doesnt work???
Post by: AudioguyII on May 22, 2006, 01:50:06 AM
So nice to have my first GSSL in it's rack with all the trimmings.

Only problem is the make-up gain doesnt work now. The only hings I've changed was racking it , attaching the meter and replacing the 2k meter resistor with a 20k resistor because my Sifam Al29 are 100uA instead of 1mA...

Can anyone shed some light on this???
Thanks
Title: SSL HELP THREAD!!!
Post by: gyraf on May 22, 2006, 03:18:38 AM
If you read back through this thread, the most common reason for make-up gain not working is wrong wireing of the bypass switch.

So check wireing, shorts, and soldering..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on May 23, 2006, 04:34:00 AM
My two Golden DBX 202C VCAs are on the way. Is there anything that I should know when installing them except that I remove all other components from the VCA sections?
Title: SSL HELP THREAD!!!
Post by: gyraf on May 23, 2006, 04:48:24 AM
That should be all that's needed..

Jakob E.
Title: SSL HELP THREAD!!!
Post by: Purusha on May 23, 2006, 05:02:20 AM
OK, thanks Jakob.
Title: SSL HELP THREAD!!!
Post by: Greg on May 23, 2006, 06:54:20 AM
Did you by sockets for them, or are you planning to just solder straight to the board?
Title: SSL HELP THREAD!!!
Post by: Purusha on May 23, 2006, 07:24:42 AM
Well, I wasn't even thinking about the sockets yet. What do you suggest?
Is it hard to get them?
Title: SSL HELP THREAD!!!
Post by: BR on May 23, 2006, 10:12:14 AM
Hey guys,
still working on mine here..
I got everthing where it needs to be.  Using 2180LA.
I ran the unit through a anylizer and it was outputing +24db with 45% distortioin..  I bet it sounded killer.
So I started checking the power around the chips, (with the help of my good friend amorris).  The rails were fine but I read ,on the 5534s, 12V on pins 1 and 8.  I'm not sure if that is right.  Whenever I pull the chip and measure the sockets I have no DC reading at those pins.
Is this normal or do I have a bad chip or something??
I did replace that particular chip with another one and had the same reading.

thanks
Gil
Title: SSL HELP THREAD!!!
Post by: Greg on May 23, 2006, 04:42:57 PM
Purusha, I used sockets that are often used for socketing discrete opamp amps, but I did have to carefully drill the holes on the PCB a little bigger to get them to fit. Check in my API parts list (Fabio version) for the part number.
Title: SSL HELP THREAD!!!
Post by: roginator on May 23, 2006, 05:12:29 PM
PAD2002TS
http://www.proaudiodesign.com/productinfo.php?ItemID=P60008
did anybody tried that VCA in GSSL instead Gold 202c ...

Pro Audio Design said that this State of the art VCA is direct replacement for old 202c...

I wonder how that sounds ....since it using 4 THAT 2181LA per VCA
Title: SSL HELP THREAD!!!
Post by: Greg on May 23, 2006, 05:55:35 PM
With a list price of $179, I doubt that anyone tried it... but I may be wrong.
Title: SSL HELP THREAD!!!
Post by: Purusha on May 25, 2006, 12:51:32 PM
Quote from: "Greg"
Purusha, I used sockets that are often used for socketing discrete opamp amps, but I did have to carefully drill the holes on the PCB a little bigger to get them to fit. Check in my API parts list (Fabio version) for the part number.


Sorry, can you direct me to your parts list?
Title: SSL HELP THREAD!!!
Post by: Greg on May 25, 2006, 01:17:40 PM
Go to search... Look in the  "The Lab" only and put "Greg" in the author field. It should come up on the first or second page. It's a thread called, "Greg's Parts List - All"

It'll be in there.
Title: SSL HELP THREAD!!!
Post by: tommypiper on May 26, 2006, 02:36:19 PM
I inherited a GSSL board that was stuffed but not working.  When I plugged it in one of the 5534 chips exploded.  

Voltages are not healthy.  I've now replaced all the parts in the power supply portion but still not getting correct voltages.  Can someone steer me to a next diagnostic or idea?  

I'm not getting correct voltages off the regulators. But replacing the regulators has not helped.  I've also replaced the power transformer and the rectifier.  Resistors test fine.  Already replaced the first 1000 uF caps and 22uF caps too.  Where do I look next?

This pcb board has been worked on by two people now and neither one of us can find the problem.  It's REV 7 board.  Is there something peculiar on this REV 7 we should know?  Any ideas?  Help.
Title: SSL HELP THREAD!!!
Post by: tommypiper on May 27, 2006, 09:10:04 PM
GSSL Help?
Title: SSL HELP THREAD!!!
Post by: gyraf on May 29, 2006, 04:21:25 AM
Piper,

Nothing to do but check, check, and double-check. And read this looong thread.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tommypiper on May 30, 2006, 10:52:53 PM
Yep.  I'm worried about lifted solder pads having broken off and then buried under new solder.  And no longer connected to the trace.  The regulators and caps have been replaced several times, by two people, and I also replaced several other parts and noticed at least two solder pads lifting and breaking free.  

I've also been suspecting broken traces and solder bridges.  Between the two of us scraping possible solder bridges I found at least one trace that got cut.  

I've also been testing for continuity on traces to verify them, and to verify lack of solder bridges, but I find the components appear to spoil the continuity readings.  So I'm somewhat in the dark about whether to trust these readings on a stuffed board.  Will that work?

The voltage readings with new parts do not produce logical results.  I'm getting irregular voltage right off the regulators.
Title: SSL HELP THREAD!!!
Post by: gyraf on May 31, 2006, 05:36:12 AM
Don't just replace parts. Trace signals through the unit (search post about this) - that way you'll know where to look for problems.

Jakob E.
Title: SSL HELP THREAD!!!
Post by: tommypiper on May 31, 2006, 04:28:15 PM
Thanks.  Searched and read what I could find.  With yet new regulators, tracing the current, I find:

-Transformer feeding 16.4 VAC from both leads of the transformer entering the board.
-Rectifier showing + / - exactly 21 VDC each side.
-Regulator 7915 showing -15.2 VDC.
-Regulator 7815 showing +12.0 VDC.
-Regulator 79L12 showing -12.2 VDC.
-Regulator 78L12 showing +12.1 VDC.
-At "-12" mark on back of board I am showing -20.8 VDC.
-At "+12" mark on back of board I am showing +12.1 VDC.
-At "-15" pad mark on back of board I am showing -15.2 VDC.
-At "+15" pad mark on back of board I am showing +12.0 VDC.
-At "-15" mark on bottom, back of board I am showing -15.2 VCD.
-At "+15" mark on bottom, back of board I am showing 0 VDC.

So many wrong voltages.  
So, 7815 is suspect, apparently again?  That will be regulator number 5 in that position.  (I'll search for broken pads when replacing, maybe that's causing it.)

Where could the -20 V be coming from when it's supposed to be -12V?

Why is there 0 V at the bottom of the board when it's supposed to be +15?  

I'm not having success corrolating components on the board with the schematic.  Which cap, or point on the schematic, corrolates with the "-12" mark on the back of the board, please?  

Likewise, which points on the schematic corrolate with the other pcb marked voltage test points?  That would be a huge help in following the schematic pathways on the physical board.
Title: SSL HELP THREAD!!!
Post by: Greg on May 31, 2006, 07:46:36 PM
Measure resistance from +15V to ground... see if you have a short.
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 01, 2006, 01:15:39 AM
No, thanks, but there's no short on the +15.  And with the new regulator it now shows +1.01 volt.  Weird as a witches whistle.

I spent the day checking every conceivable place for continuity.  Thought maybe I'd be lucky today.  There is one area under the sidechain VCA that is showing continuity across traces.  I cannot find it exactly on the schematic - can someone help me with this?  How do we locate components on the schematic?  I'm struggling to do this without part numbers.  I've cleared all the solder away and made many visual inspections and it still shows continuity where I don't think it should.  I wonder if the continuity is passing through a cap or resistor or some other pathway?  Maybe it's normal?  If I could show you on the schematic it would help.  How can I identify this trace?

Everything else checks out fine for continuity.  The whole board is cleaned and inspected up the bloody wazoo.

I replaced reg 7815.  Now getting consistent +14.86v and -15.3v.  Not great, but maybe not my problem either.

12 volt regs doing fine.

But I am still getting -20.8 V on the -12v test point.  It's driving me nuts.

I'm at a loss.  The only possible theory I can find is that trace under the sidechain.  Would that cause these issues?  

Can someone tell me where the -12v test point is on the schematic?  And the lower +15v test point, please?  

I'm dreaming about this board in my sleep.
Title: SSL HELP THREAD!!!
Post by: fucanay on June 01, 2006, 01:31:44 AM
Between which pins is it showing? I think there should be continuity between some of them.

Also, if you have iChat on, ping me at fucanay. It's an AOL name, not .mac.

Matt
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 01, 2006, 01:43:16 AM
Hi Matt, thanks, you've cheered me up already.  Sorry, I don't have iChat, I'm on a very old Mac...

Counting from the edge of the board, it's the traces connecting to pins 2 and 3 which show continuity under the sidechain VCA.
Title: SSL HELP THREAD!!!
Post by: fucanay on June 01, 2006, 01:53:15 AM
Quote from: "tommypiper"
Hi Matt, thanks, you've cheered me up already.  Sorry, I don't have iChat, I'm on a very old Mac...

Counting from the edge of the board, it's the traces connecting to pins 2 and 3 which show continuity under the sidechain VCA.


Yeah, I just tested mine and I show it too.

Have you checked the resistor values all around there? Like the 3k9 that leads to the -12 test point? Maybe you have a wrong value there.

Matt
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 01, 2006, 10:37:01 AM
Thanks.  I tested all the resistors when I got the board.  

I don't see any 3k9 near the -12v test point.  I only see two 10s, near the small regulators.

The 3k9 near the sidechain is testing 3k2 while on the board.  I'll pull it off and test it...  It tests 3k83 off board.

Can someone help locate the -12v test point on the schematic, and the +15v test point, please?
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 01, 2006, 11:00:23 PM
Maybe this will jog something.  Humor, if nothing else.

Odd voltage readings:
TL074:
pin 1 -.7v
pin 2 -.8v
pins 6 & 7 -.8v
pins 8 & 9 +1.7v
pin 13 -.8v
pin 14 -.5v

TL072:
pin 2 +1.8v
pin 6 +1.5v

Sidechain VCA:
pin 5 -8.8v
pin 8 -8.0v

Output 5532:
pin1 +.9v
pin2 +.6v
pin6 +.9v
pin7 +.9v
pin8 +14.8v

L & R VCAs:
pin3 -15.2v
pin5 -15.2v
pin8 +.7v

These don't look corect to me.  Are *any* of them correct?

I'm still getting -20v at the -12v test point on the back of the board.  This is the negative lead on one of the 22u caps.  Is this actually supposed to be -12 or -20?  Can anyone tell me which cap it is on the schematic, please?
Title: SSL HELP THREAD!!!
Post by: fucanay on June 02, 2006, 12:02:22 AM
I'll be checking everything on my board once my son goes to bed, but I think I've figured this out.

After doing some tracing for you, I believe that the -12 on the back is just identifying the rail, not a test point. If you notice, the negative (-), of the -12V on the bottom of the board,  is actually touching the trace that is -12. It connects to pin 11 on the TL074 and the 3k9 resistor in the side chain. It also goes to pin 4 on the TL072. If you're getting that, I'm sure the +/-12V part of the PSU is good.

I'll post my results in a couple hours.

Matt
Title: SSL HELP THREAD!!!
Post by: fucanay on June 02, 2006, 12:58:51 AM
Are you testing with chips in or chips out?

Matt
Title: SSL HELP THREAD!!!
Post by: fucanay on June 02, 2006, 02:51:57 AM
Ok, I went in and tested with chips out. I don't know if that's the same as how you did it, but it's the state my board is in right now.

Rails
+14.69
-14.98
+12.02
-12.17

NE5532 Output (channels weren't identical, but close. I'm only writing one down.)

1. 0.44V
2. 0.44V
3. 0V
4. -14.98V
5. 0V
6. 0.44V
7. 0.45V
8. 14.69V

NE5534 Input (channels weren't identical, but close. I'm only writing one down.)

1. 0V
2. 0V
3. 0V
4. -14.98V
5. 0V
6. 0V
7. 14.69V
8. 0V

NE5534 VCA section (channels weren't identical, but close. I'm only writing one down.)

1. 0V
2. 0V
3. 0V
4. -14.98
5. 0V
6. 0V
7. 14.69V
8. 0V

Channel VCAs

1. 0V
2. 0V
3. 0V
4. -0.52
5. -14.97
6. 0V
7. 14.69V
8. 0.44V

TL072

1. -.03V
2. -.03V
3. 0V
4. -12.17V
5. 0V
6. 0V
7. 0V
8. 12.02V

TL074

1. 3.35V
2. 3.35V
3. 0V
4. 12.02V
5. 0V
6. 3.14V
7. 3.14V
8. 0V
9. 0V
10. 0V
11. -12.17V
12. 0V
13. 3.56V
14. 3.84V

Sidechain VCA

1. 0V
2. 0V
3. -0.03V
4. 0V
5. -8.26V
6. 0V
7. 12.02V
8. 3.4V

I hope this helps.

Matt
Title: SSL HELP THREAD!!!
Post by: gyraf on June 02, 2006, 04:38:55 AM
Quote
NE5532 Intput (channels weren't identical, but close. I'm only writing one down.)

1. 0V
2. 0V
3. 0V
4. -14.98V
5. 0V
6. 0V
7. 14.69V
8. 0V


Input opamps are 5534, not 5532!!!
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 02, 2006, 10:47:42 AM
Quote from: "fucanay"


...I believe that the -12 on the back is just identifying the rail, not a test point.

Matt


Thanks, Matt.  It would be nice if the maker of this board could verify that or answer this question I have been asking many times.
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 02, 2006, 10:49:45 AM
Matt, there are many discrepancies between your readings and mine in the chip sockets.  (Yes, mine were also done with empty sockets.)  You also had discrepancies between left and right, which makes me wonder what those small voltage readings mean, if anything?

My TL074 has many discrepancies:
Pins 1,2,5,6,7,13,14.  

Your board is working, right?  So I should be trying to get the same values?
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 02, 2006, 10:52:00 AM
Quote from: "gyraf"
Quote
NE5532 Intput (channels weren't identical, but close. I'm only writing one down.)

1. 0V
2. 0V
3. 0V
4. -14.98V
5. 0V
6. 0V
7. 14.69V
8. 0V


Input opamps are 5534, not 5532!!!


OUCH!  

Jeez, he just made a typo, for crying out loud.  We know what he meant.  He's trying to help.
Title: SSL HELP THREAD!!!
Post by: fucanay on June 02, 2006, 11:17:20 AM
Quote from: "gyraf"
Quote
NE5532 Intput (channels weren't identical, but close. I'm only writing one down.)

1. 0V
2. 0V
3. 0V
4. -14.98V
5. 0V
6. 0V
7. 14.69V
8. 0V


Input opamps are 5534, not 5532!!!


Ah Ha, But you'll notice that I wrote "Intput" so I am only half wrong. Hmm, maybe even more wrong. Anyway, I fixed it in the list.

Matt
Title: SSL HELP THREAD!!!
Post by: Greg on June 02, 2006, 11:47:36 AM
Quote from: "tommypiper"
(Yes, mine were also done with empty sockets.)

The regulators need to be loaded to test for proper voltages ! As long as you aren't measuring any shorts get those chips in there !
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 02, 2006, 01:37:47 PM
Hi Greg, thanks!  Nice to get an answer on here from someone.

The last time I powered it up with chips it blew up one of the 55xx chips.  Nasty pop, hiss, lots of acrid smoke...
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 02, 2006, 02:37:25 PM
OK, Matt, that was helpful to compare readings.  A couple curious points:

The schematic shows the VCA 5534s with + / - 12 on pins 7 & 2.  However, both our boards are showing + / - 15 on those pins.  Anyone?

Likewise, the schematic shows + 15v on the THAT pin 7, but both you and I measured +12v.    Which should it be?

Neither you nor I had a corresponding -12 or -15 on any THAT pin.  The schematic shows -15 on pin 2.  Do we have the same problem?  Anyone?

My output 5534s show only +.7v on pin 7 where I expect +15.  That is clearly wrong.  And maybe why the previous 5532 exploded.  I'll work on that problem, but I don't know what to make of the previous points.  Anyone?  Mr. Gyraf, can you clarify what the correct readings should be?
Title: SSL HELP THREAD!!!
Post by: fucanay on June 02, 2006, 02:52:25 PM
Quote from: "tommypiper"
OK, Matt, that was helpful to compare readings.  A couple curious points:

The schematic shows the VCA 5534s with + / - 12 on pins 7 & 2.  However, both our boards are showing + / - 15 on those pins.  Anyone?

Likewise, the schematic shows + 15v on the THAT pin 7, but both you and I measured +12v.    Which should it be?

Neither you nor I had a corresponding -12 or -15 on any THAT pin.  The schematic shows -15 on pin 2.  Do we have the same problem?  Anyone?

My output 5534s show only +.7v on pin 7 where I expect +15.  That is clearly wrong.  And maybe why the previous 5532 exploded.  I'll work on that problem, but I don't know what to make of the previous points.  Anyone?  Mr. Gyraf, can you clarify what the correct readings should be?


The only voltage I would compare to the schematic is the +/- 12 and 15 until the chips are in. I'm going to be on this tonight or maybe get off work a bit early and go for it this afternoon. It's really almost done, so I just need to wire up a few things and give it a test try.

I think you should also take into account that I have changed resistor values around the channel VCAs to account for the THAT 2181LB chips I'm using. So the voltages may be slightly off compared to your anyway. I dunno.

Matt
Title: SSL HELP THREAD!!!
Post by: gyraf on June 02, 2006, 03:01:42 PM
Quote
The schematic shows the VCA 5534s with + / - 12 on pins 7 & 2. However, both our boards are showing + / - 15 on those pins. Anyone?


Yes, the VCA's drivers has been moved to +/-15V lines. Haven't updated schematic (this is an oooold change)

Jakob E.
Title: SSL HELP THREAD!!!
Post by: fucanay on June 02, 2006, 07:29:29 PM
Ok, I messed up on the board I checked. These are not yet finished either and I have been making some of the changes that were based on the THAT datasheet. Some of them are apparently not correct because I thought I was supposed to remove one of the 10K resistors and not put a jumper in. But that makes some of the points have no voltage on the channel 5534 sockets. I had one board one way and another board the other way.


So now it reads like this.

Ok, I went in and tested with chips out. I don't know if that's the same as how you did it, but it's the state my board is in right now.

Rails
+14.69
-14.98
+12.02
-12.17

NE5532 Output (channels weren't identical, but close. I'm only writing one down.)

1. 0.44V
2. 0.44V
3. 0V
4. -14.98V
5. 0V
6. 0.44V
7. 0.45V
8. 14.69V

NE5534 Input (channels weren't identical, but close. I'm only writing one down.)

1. 0V
2. 0V
3. 0V
4. -14.98V
5. 0V
6. 0V
7. 14.69V
8. 0V

NE5534 VCA section

1. 0V
2. -14.98V
3. 0V
4. -14.98
5. 0V
6. -14.98V
7. 14.69V
8. 0V

That looks better.

Matt
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 02, 2006, 11:20:10 PM
Big Thanks to Matt.  :guinness:  
We both got our units running and passing audio.  :grin:  Mine is not compressing.  In case anyone knows, mine doesn't have the bypass switch wired in (I'm looking for a switch in meantime), would that be the reason it's not compressing?
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 03, 2006, 11:35:20 PM
Jacob, or anyone.  My last +15v regulator was actually putting out -1v for about 30 minutes before I tracked down the problem.  Could I have damaged any of the caps or chips during that period?

My question is, should I worry about damaged components from it having run with -15v and -1v on the power rails?

Second question.  No compression.  I do not have the bypass switch.  Will the compression work without it?  What do I need to do?

The switches are wired backwards in orientation from the board.  Could that be a problem?  (I didn't wire them, so it's a mystery to me.)

It passes clean audio but does not compress.
Title: SSL HELP THREAD!!!
Post by: tommypiper on June 05, 2006, 12:22:27 AM
I'm stuck.  I spent two days reading this help thread over and over and took 15 pages of notes.  

I am trying to trace the signals, but I don't understand everything.  I have traced backwards from the VCAs where there is no signal and finally found a small AC signal on Pin 6 of the Input 5534, but I am confused about where it goes next.   I can find the signal on the upstream side of the 27k resistor, but not on the dowstream side, there it disappears.  

(Both channels are doing this, so I don't think it's a bad