GSSL HELP THREAD!!!

[bassculture]

VU meter question :

i build mine in a 2U rack & took this one at farnell :
7758340 - ANDERS ELECTRONICS CV18X1MA - 1mA - 80mm * 67mm (30€ !)

if you build 1U :
143509 - unbranded - 100µA (13€)

also take a look @ conrad.de if you are in europe.

cheers

 

[SIXTYNINER]

LONG LIFE
TO BASSCULTURE
Thanks!
6T9R

 

[bassculture]

thanks,  ;D

take care with the 100µA you will have to solder a 330R resistor across the + and ground of the meter. (= wired paralell)

this is a starting point & maybe you'll have to adjust this value because of the internal resistance/impedance of the meter...

cheers

 

[guitarguy12387]

Quick noob question:

TL072 or LF353N for this project? What's the difference/ which should i go with (i'm referencing greg's bom, thats why i ask)?

If TL072/TL074, which model/suffix should i look for?

Thanks!

 

[tongenerator]

Hello,

i am going forward to build an gssl is well.
i have only build one midibox project, but with sucess.

i am wondering if there are some mayor issues that can ocure during building.
unfortunatly i have been to dull to find some realy bad problems that can happen.

so do you have any tipps for me, what do i have to look after so it wont end up in
a desaster, or is it realy quiet simple? what are the most common issues, which mostly
come up?

thanks or any replay

Mark

 

[MartyMart]

Hello,

i am going forward to build an gssl is well.
i have only build one midibox project, but with sucess.

i am wondering if there are some mayor issues that can ocure during building.
unfortunatly i have been to dull to find some realy bad problems that can happen.

so do you have any tipps for me, what do i have to look after so it wont end up in
a desaster, or is it realy quiet simple? what are the most common issues, which mostly
come up?

thanks or any replay

Mark

Hi Mark,
          First "tip" is to take your time with it and don't rush anything !
Order parts carefully - it's quite a small board and things get tight around the I/O section.
You need very small 0.1uf ( 100n ) poly caps ( 5mm lead spacing ) and also small good quality 22uf's
which are also quite crammed in here and there.
Watch your soldering on the PCB bottom as it's easy to cause a "short" - use a good tinned iron with
a small pointed tip and keep it clean !
Follow all the advice here on the project and look stuff up in the search - you'll be fine

That's all.
Marty.

 

[tongenerator]

sounds great to me, thanks for your tipps 

 

[caseyc]

Ok, i'm new here, been building pro stuff for a long time....

I just wanna share my information to people that are having troubles with "hum noise" in the SSL clone.

Failure: the components/pcb solderings are checked out OK but you still got a "hum noise with high makeup settings" ?

What's causiing this: It's a bad produced pcb....the ground layers on the pcb are so thin that they become a resistance...making the ssl hum...
Measure the ground between two points on the main pcb when it's running...it should be zero, but if you have "Hum" it's not.

Solution: well, if you have made your own pcb, solder groundwire on every groundlayer on the pcb = no hum. It does NOT help soldering a wire between the points!
If you have bought a pcb with coat/barnish on it...well, you have some nights in front of you fixing it...!

Ok, all for now. /Casey

 

[Chrome Heart]

Im under the impression that Gustav supplies many boards to builders on this group and personally Ive had very little trouble with ground noise, and I have built three of these units using Gustavs boards. Id like to hear from builders who actually are having ground problems and see what boards they are using.

 

[feza]

Solution: well, if you have made your own pcb, solder groundwire on every groundlayer on the pcb = no hum. It does NOT help soldering a wire between the points!
If you have bought a pcb with coat/barnish on it...well, you have some nights in front of you fixing it...!

Ok, all for now. /Casey

Welcome Casey!

There's another solution. Building an off-board PSU works as well. Those PSU boards can be bought from Mnats (1176 boards seller) and really am excited about the build. Right now I am drawing the wiring of all the PCB's combined for my GSSL. It's quite complex for me but if you are handy with building units? Feel free to correct it by then.  

Later,
Dennis

 

[Eje2005]

Question: When using That2180LB , if i skip the 50k trimmers do i still need to cut leg #4 on the vca´s ?

 

[feza]

Question: When using That2180LB , if i skip the 50k trimmers do i still need to cut leg #4 on the vca´s ?

As far as I know yes. Perhaps bending the pin would be better.

If you are using the pre-trimmed VCA's check this thread as well if the Turbo mod is going to be installed :

http://www.groupdiy.com/index.php?topic=29386.0

 

[Eje2005]

Thanks man thats great info.
So just to be sure, its the 4th leg from the left?

 

[feza]

Thanks man thats great info.
So just to be sure, its the 4th leg from the left?

Be sure to check this as well if you do not build the GSSL with the Turbo mod in mind :

http://diy.fischerworks.com/gssl_vca.shtml

To answer your question it is the fourth pin from the left yes. But hey check this mighty thread, tons of questions with good answers.

 

[juanjo]

hi,
it's the first time i post on here but i already read many many pages on this forum!

i built 2 units of the GSSL and it sounds superb, thank you jakob for that wonderful design!

both units sound great but i have the same problem with both clones....
1 out of 3 times, for no reason, i have no +15V (the -15V, +12V and - 12V are fine)... when i reboot the devices the +15V works fine and so does the clone. i just can't understand why it works 2 out of 3 times and the third time it doesn't...
i double checked the transfo (a 2x15V 30VA toroid) and it delivers both 15V's every time i turn it on.
Could it be a transformer issue? maybe i should use a 2x18V?
I mounted a minipsu (calrec psu from gyraf) with the same components, sane transformer, and it works every time, no matter how many times i reboot it. Do you guys think my toroid is too weak to provide for both the 15V and 12V rails?

thanks very much for your help!
juanjo from Paris!

 

[feza]

Hey,

I'm almost finished drawing the wiring diagram. The only thing I do not know is the following :

When building my GSSL it features 10 PCB's (hope it fits ) and all needs power to work. To make a story short the relays (Igor XLR kits) is connected in serial with each other but needs 12v to work properly. So 12 volts (from Mnats PSU) goes directly in the relays. There's an input and output on the relays and with the last relay in the serial connection it ends with the "in" connected only, the output is not in any kind of connection. The question is ; how to power the mainboard's plus and minus 12v rails? There are more components needing the 12v rails. With an off-board PSU the bridge rectifier and the two big capacitors are not mounted.

It is very important for me to know how the 12v rails are powered on the GSSL board with this configuration. With that answer I can finally complete the drawing.

Thanks!

EDIT : I got it. Finalizing diagram..... ;D

 

[museic]

Hi all, new to the board. I've been wanting to DIY for a long time and finally I think I'm going to go ahead and build a GSSL and see what happens. I'm getting my parts orders together and have been using Gregs SSLCloneParts List. It seems that Digi-Key no longer stocks a few of these parts. I was wondering if someone could help me out where to find them. They are...

Semiconductors - #1 IN4148 Silicon Diode (0.15A 75V DO-35) and #2 Regulator 79L12 (TO-92 -12V 100mA)

Tantulums - #3 0.47u 50V and #4 6.8u 50V

Sorry if this has already been covered, but I haven't found any mention of it in the pages I've read. I'm located in the U.S. by the way so a U.S. distributor would be best.

Thanks!!!

 

[Chrome Heart]

Hey Museic, and welcome to this very helpful board. The digikey parts numbers you need are 1N4148-TPMSTR-ND - TAP474K050SCS - T356F685K035AT. The 7912 I get from Mouser. Part # 526-NTE1903
Cheers, and have a fun build. Watch those solder bridges!

 

[JW]

Hey guys,
I bought a GSSL from a member here, and am finally getting around to messing with it.

Please forgive me for my newbie questions. I have a few.

1. This one actually has DBX 202C's in it. In this regard, is it necessary to undo the revisions that Jakob describes on his site, which I think I'm understanding are supposed to correspond to the various THAT chip versions but not if you have the original 202s?:

"Component overlay revised to properly describe three mods necessary: Unity gain (two 15K resistors changed into 27K, look here), Ratio adjust (100K changed to 127K look here), and threshold de-sensitize (adding a resistor between pcb and threshold pot + look here)

2. What are some proper measurements to find out if the GSSL is working/calibrated properly

3. The guy I bought it from said the meter didn't work properly, but I found that simply reversing the leads to the meter made it swing the right way. It appears to be reading compression but I want to measure the meter to make sure that it has the right resistor value corresponding with it.  How do I figure that out? (It's a Sifam with the part number 26868-01-0015 on it. I googled that and didn't come up with the meter model.  It's a 2RU tall meter, so it's definitely not the one Jakob has on the original 1RU unit)

4. If I understand correctly the turbo board is to remedy the need to sum the two channels, which is an issue a lot of folks had with the original GSSL design. If mine has DBX 202's in it, will the turbo board with THAT 2180 chip still work right with this unit? It has a THAT 2180 in the sidechain.

5. Because the power transformer came loose during shipping the secondary leads broke off at a point where the copper wire is un-solderable. Right now, I've extended these leads, but with 22 AWG wire. Is this sufficient is the current draw enough that I should bump up the gauge? (This is between the secondaries and where they connect to the main board)

Sorry for all these questions. It just seems like there are such few versions with the 202's so I'm sort of wondering what the differences are in the build.

 

[onlymeeee]

1.  I quote Barclaycon: If I remember rightly the original layout was done with the DBX202 package in mind, so the resistor values on the PCB will be correct except for the fact that ratio resistor is changed to 127k (120k is close enough) and the resistor feeding the VCA is changed to 27k because the balanced output gives +6dB gain.
(In actual fact the value should be 30k if you want unity gain).

4.  Yes, and well worth it
5.  My transformer that I use has 22awg.