GSSL HELP THREAD!!!

[jordan s]

I did all the mods for using 2181LB VCAs and now instead of being jumpy, it sounds like it's either compressing way too much no matter what I do or it's just attenuating the signal a lot. When I move around the release switch, the level gets a lot louder while switching. If I use a ratio of 4 or 10, I can't even hear the signal anymore, nor can I with fast attack times.

 

[ptron]

Well, I got it to power on but it's not really functional in any way. All kinds of weird stuff is going on. For one, it doesn't seem to be compressing at all. The meter is completely pegged when not in bypass. Threshold pot does nothing. The release switch makes loud popping noises when switching and worst of all, it's making very loud scratchy, static noises. Also, one side is coming through a lot louder than the other. I don't even know where to begin with this. I've checked my wiring, all resistors, polarity of all polarized parts. Any ideas?

Update*, I swapped the 2180 VCA's in the VCA section with some 2181. Now it's compressing seemingly randomly, jumping all over the place, sometimes completely lowering the whole signal. The controls seem to have an effect on how it's compressing but not the desired effect. Now that I've got this all wired and I have all the expensive parts, I might just populate a new set of boards and swap them in. I could probably do it in an evening, who knows how long it could take to trouble shoot this. These boards have been in the hands of several novice builders before me and there's no telling what the issue is. At least I can keep track of myself when I populate the boards and be extremely through.

i kinda had the same problem somehow ended up being the 10X molex on gssl main board (a pad was broken) i oversolder the female part of the molex thingys, too much force... i broke it .. but my problem was very similar does your unit pass audio when its off? .. anyways try fiddling a bit around that area(just touching the board around the header no pressure intended) in mine helped me see the problemo.. but if its not broken there i figured it was on the + connection of the header maybe something wrong round there
http://www.groupdiy.com/index.php?topic=42706.0

hope u find it soon

 

[jordan s]

I checked all the connections between the main board and the switch board and it's all good. The hard part about this is that these boards were assembled in India or something and I don't know where the person got the resistors but the colors are really hard to tell. Red looks like orange, green looks like yellow, etc. It's a bit tricky to tell if they're the right resistors unless they can be checked with a meter in the circuit and I already checked all of those.
I also tried replacing the tl074 and tl072. When I got the board, the rectifier was blown so who knows how this thing has been abused.
Even with no signal, it acts the same way. Compressing way too much, fluctuating wildly.

 

[jordan s]

I tried to trace the sidechain signal with some headphones and I'm noticing some static popping noises at pins 1 and 14 of the tl074 when not sending signal. When I am sending signal, the sound on these pins is very distorted, sometimes completely noise. Could this be the cause of my issue? What could cause this? The audio at pin 7 is clean and noise free.

 

[jordan s]

Well, I may never know how that noise was getting into my sidechain and why it's not there anymore. I'm going to call it mysterious RF interference and never think about it again. I was able to get it working, calibrate the meter and properly adjust the ratios. Everything is looking and sounding great. I briefly compared it to the Waves SSL buss comp on drum buss duties and they sound (un)surprisingly similar. I'm happy that this is done. Now I can tighten things, close it up, put the knobs on run some rock through it. Pictures to come.

 

[wahfreak]

Hi guys,
Can you help me out on a simple question. I'm trying to hook up my transformer (Amveco) 62063 but I don't think I'm measuring it right or it's not working correctly. I have the yellow and red primaries wired together in parallel and connected to the IEC "N". The purple and black are also wired in parallel and connected to the IEC "L". Ground wire is connected to the chassis.

I have the secondary red and brown wired together (which is supposed to go to pin 2 "0V" on the board) in the upper right hand of the pic. The green and blue are suppposed to go to pins 1 and 2 of the SSL Rev #7 board.

I looked at some previous threads about wiring this exact xfmr but I can't seem to figure out what I'm doing wrong.

What is the right way to measure the voltage on the xfmr and what should I expect to see??

Thanks

 

[MeToo2]

We could do with some more information to confirm some stuff and be able help you out properly.

Where are you located? Europe or USA? Is the local power 110V or 240V ac?

Assuming the wiring for the transformer is the following.
http://www.amveco.com/Miniature_Low_Profile_Transformers_2.htm

Then if your mains is 110V you would connect yellow (primary) to red (primary) to IEC N, and black to violet to L. E on the IEC would go to the chassis.

Red (secondary) would be connected to brown (secondary) and to the centre pin = 2 of the 3 pin header (0V) and also to the chassis via pin 1 of your input XLRs.

Green (secondary) connects to one of the outer pins of the 3 pin header, and blue to the other outer pin (doesn't matter which as it is AC)

So that broadly agrees with what you've written previously.

Mains power input should measure 110V AC between yellow/red (primary) and black/violet (primary) using a multimeter suitable for measuring mains voltages.
Have you checked that you fitted a fuse to the IEC connector? Most come delivered without a fuse fitted.

Output of the transformer should be around 15-18V AC measured with an AC multimeter between green and red/brown and also the same 15-18V AC between blue and red/brown. 18V AC is the spec for the output under no load conditions.

The voltage across the large 1000uF 35V power capacitors should be around 20-25V DC. There should be very little AC across these caps as the current draw of a gssl isn't high: around 40mA-100mA (depending on side chain and relay options etc.)

You can also measure the output of the regulated power supply at the +15V and -15V straps just below where the on board transformer would be mounted. This should be pretty much exactly 15V DC (at least within 0.5V anyway).

BTW you seem to be missing a 5 pin header on the input...... and also be sure to check out the orientation of your TL074. Isn't it in upside down?

I found powering up with just the passive components inserted, and then inserting the IC's one by one was a good way to debug. Mind you I also used a current limiting lab power supply to avoid frying anything accidentally.

 

[wahfreak]

We could do with some more information to confirm some stuff and be able help you out properly.

Where are you located? Europe or USA? Is the local power 110V or 240V ac?

I am in the US, so it's 110 but I measure 121 from the IEC.

Assuming the wiring for the transformer is the following.
http://www.amveco.com/Miniature_Low_Profile_Transformers_2.htm

Yes, that's the one.

Then if your mains is 110V you would connect yellow (primary) to red (primary) to IEC N, and black to violet to L. E on the IEC would go to the chassis.

Red (secondary) would be connected to brown (secondary) and to the centre pin = 2 of the 3 pin header (0V) and also to the chassis via pin 1 of your input XLRs.

Green (secondary) connects to one of the outer pins of the 3 pin header, and blue to the other outer pin (doesn't matter which as it is AC)

So that broadly agrees with what you've written previously.

Thanks, thats what I thought.

Mains power input should measure 110V AC between yellow/red (primary) and black/violet (primary) using a multimeter suitable for measuring mains voltages.
Have you checked that you fitted a fuse to the IEC connector? Most come delivered without a fuse fitted.

Output of the transformer should be around 15-18V AC measured with an AC multimeter between green and red/brown and also the same 15-18V AC between blue and red/brown. 18V AC is the spec for the output under no load conditions.

I was measuring ~18V between the  red/brown, green and blue, but I assumed it should be 15V. This is why I asked. I didn't want to fry anything if I wired it.

The voltage across the large 1000uF 35V power capacitors should be around 20-25V DC. There should be very little AC across these caps as the current draw of a gssl isn't high: around 40mA-100mA (depending on side chain and relay options etc.)

Thanks, I'll check that tonight when I get home.

You can also measure the output of the regulated power supply at the +15V and -15V straps just below where the on board transformer would be mounted. This should be pretty much exactly 15V DC (at least within 0.5V anyway).

I'll check these too!

BTW you seem to be missing a 5 pin header on the input...... and also be sure to check out the orientation of your TL074. Isn't it in upside down?

I'm waiting for the header to be delivered. I'll also double check the pinout on the TL074.

I found powering up with just the passive components inserted, and then inserting the IC's one by one was a good way to debug. Mind you I also used a current limiting lab power supply to avoid frying anything accidentally.

Thank you, thank you, thank you for your time and effort!!! I really appreciate it.

 

[jordan s]

So even though I wasn't getting any hum out of my unit at home, I decided to add the CRC board in my unit. While the CRC board is putting out a solid +/-24v, the 7815 will not drop it down to +15v, instead it puts out -1v. I did make sure to have +24 going to the 7815 and -24 going to the 7915. When I bypass the CRC, it's all working as it should again. Weird. Any ideas?

 

[MikeClev]

So even though I wasn't getting any hum out of my unit at home, I decided to add the CRC board in my unit. While the CRC board is putting out a solid +/-24v, the 7815 will not drop it down to +15v, instead it puts out -1v. I did make sure to have +24 going to the 7815 and -24 going to the 7915. When I bypass the CRC, it's all working as it should again. Weird. Any ideas?

Is your ground definitely connected to the CRC board and to your GSSL board? Its worth checking! Also check the connections between the CRC and power transformer.

 

[jordan s]

There is no separate ground connection on the CRC board, all 3 terminals are connected properly on each side. As far as I can tell, the CRC board is putting out proper voltages and the compressor works perfectly well when the CRC is bypassed. It's a mystery to me. I might just leave it out, I'm not hearing any hum without it.

 

[Bob1991]

Hi,

I was wondering which option to choose to upgrade my GSSL: the super sidechain mod, OR the turbo board..
I'd like to use my GSSL as a masterbus compressor too, so the bass-rolloff filters in the super sidechain are a good choice. But in fact it is not really stereo compression, both channels are compressed just the same..

So maybe for mastering usage the turbo board is a better choice, as it's a 'real' stereo compressor then.

What I'd like to know is, is the over-compression of loud/centre panned bass sounds also reduced with the turbo mod?

Which board should I choose? - I think that choosing them both is a little complicated..

 

[tzman]

Hi,

I was wondering which option to choose to upgrade my GSSL: the super sidechain mod, OR the turbo board..
I'd like to use my GSSL as a masterbus compressor too, so the bass-rolloff filters in the super sidechain are a good choice. But in fact it is not really stereo compression, both channels are compressed just the same..

So maybe for mastering usage the turbo board is a better choice, as it's a 'real' stereo compressor then.

What I'd like to know is, is the over-compression of loud/centre panned bass sounds also reduced with the turbo mod?

Which board should I choose? - I think that choosing them both is a little complicated..

Just some quick answers:
The Turbo board does indeed get rid off the effect of too much compression of center panned bass.

I too couldn't decide what to use and am currently building a GSSL with both a SSC and Turbo board. I'm going to make this switchable, so you will be able to choose either your GSSL with one SSC (mono), OR your GSSL with Turbo board and without SSC (stereo).
This isn't complicated at all and I would be glad to help you out.

 

[Bob1991]

Ah, that's a nice idea.. So you can select both options, but not at the same time. Quite nice solution I think.

If you got some schematics for wiring those 2 boards into your GSSL, I'd like to hear from you how you did it

 

[chrispbass]

Ah, that's a nice idea.. So you can select both options, but not at the same time. Quite nice solution I think.

If you got some schematics for wiring those 2 boards into your GSSL, I'd like to hear from you how you did it

+1

 

[mac]

having built a few of these now, I am not really sure why you would want to run material through the GSSL without the turbo or turbo and side chain filters. I originally built one stock, then added a side chain which I found I used most of the time. Then one with just a turbo, and now I have one with a custom side chain filter and turbo on it.
I am just not sure of an occasion when a single detector GSSL would be the best treatment - not turbo - not with a side chain filter ....

but I am an options junkie ...... so I guess the more options the better...make one with all the options and switchable output transformers as well!!!

Mac

 

[tzman]

Ah, that's a nice idea.. So you can select both options, but not at the same time. Quite nice solution I think.

If you got some schematics for wiring those 2 boards into your GSSL, I'd like to hear from you how you did it

No problem:
http://www.groupdiy.com/index.php?topic=16113.160

Use the drawing stitch-o made at the bottom of that thread.

Instead of a DPDT switch you could use a relay or two relays as described by Holger here:
http://www.groupdiy.com/index.php?topic=32341.0

Cheers!

 

[ptron]

i did same thing as described by stitch-o he even helped me out with some specifics! my compressor is great to be honest i almost always end up with single sidechain thru one of the filters from the SSC board when i master (altho i always do electronic music which kinda makes sense to let that thump thru)...
the turbo is really really nice too but it sounds much more compact for that style of music. and to be honest i would think for most styles i want the bass thumping away a bit more than the rest of the spectrum.
anyways this way is really good choice !

@ jordan .. i hope harpo comes up with something cus your problem seems very weird.. is your build working properly now?

 

[MikeClev]

Here is a youtube video explaining why the GSSL Turbo is worth installing.

http://www.youtube.com/watch?v=EQD8GPhFGYE

The video was created by this forum's 'SSLTech', the inventor of the Turbo mod.

I have the turbo installed on both my GSSLs, once I tried it I knew I needed it on both.

 

[Bob1991]

Thanks tzman!

The only thing i dont understand is how to wire the bypass switch with these mods, I'd like to use a standard on/off pushbutton as a bypass switch instead of the lorlin rotary one i currently have installed..