GSSL HELP THREAD!!!

[dissonantdissident]

I still haven't been able to chase down the problem in my build, unfortunately.  I've double checked component placement, and all the resistors, etc, seem to be in the proper location, when double checked against the layout, and I'm getting proper voltages at the IC pins and wires.  Resoldered any less-than-shiny welds, etc.  Still, the second I turn it on, the meter flies over to the max and the VCAs clamp down. 

It's passing audio and the makeup gain is working, but the audio that passes is heavily squished and distorted.  I've been told that this is a sign that voltage is being dumped into the VCA, but I'm having a hard time finding where.  I'm no electrical engineer, but I've modded dozens of microphones and built numerous CAPI kits and DOAs.  Basically, I'm pretty new to electronics, but I know my way around an iron, and can follow a schematic, pretty good.  With the component placement and test voltages working out, I've hit the limit of my personal skills.

I'm about to take it to the repair shop, but the local guy is pretty horrible.  Last time I used him, I brought him an ashly compressor.  Two months and close to $200 later, he gives it back to me and tells me that one opamp was bad.  Powered it up, and the problem came back, within minutes.  Anyway, I try and avoid using him.

I've tried going through the thread, but it's hundreds of pages long and I haven't found a fix, yet.  Any help would be appreciated.   

 

[ding]

I had this similar thing happen to mine. My problem was that I put a wrong resistor around the vca. It's somewhere in this thread. Hope it's that simple for you. Check the resistors around the vca and make sure they are the right values. Good luck.

 

[Zander]

It may be the connection to the pcb where the switches should be inserted. I had this problem with a temporary molex connector while I was waiting on the right crimp sockets.


Zander

 

[dissonantdissident]

I'm gonna triple check the resistor values.  Zander, I'm not sure what you're referring to... are you talking about the cable that goes between the switch pcb and the main board?  I'll check that, as well.

 

[Gustav]

I'm gonna triple check the resistor values.  Zander, I'm not sure what you're referring to... are you talking about the cable that goes between the switch pcb and the main board?  I'll check that, as well.

Where are you located?

Gustav

 

[Zander]

I'm gonna triple check the resistor values.  Zander, I'm not sure what you're referring to... are you talking about the cable that goes between the switch pcb and the main board?  I'll check that, as well.

Yes, I meant that... I even had it backwards the first time.  :

 

[weiss]

hey dissonantdissident!
i had the same problem. but in my case it was wrong wiring of the bypass switch which made my meter act weird like yours.

weiss

 

[dissonantdissident]

Alrighty,

So, I got passed that hurdle!  Found my mess up, and it has to do with my one main complaint, about the build guide.  I didn't see anywhere where the meter was wired in, in the assembly or universal wire guides.  I made a stupid mistake and wired the meter to the  "optional relay and light" spot, instead of the meter spot on the switches pcb.  Totally my bad, but it'd be nice if the assembly guide had the meter wired in being shown. 

Anyway, I moved those wires, plugged it in, and things seemed to be working.  The meter no longer slammed to the far side, and I went ahead and threw it in the rack.  Turned on and passed signal w/o distortion!  Makeup gain working, threshold, etc, etc, all seemed to be functioning, as intended.  Unfortunately, when the VCA kicks in and does gain reduction, I am getting distortion.  This leads me to believe that my input and output sections are good !  Yay!  Unfortunately, it seems like I'm still having a problem in the VCA sections.  It's possible that I'll need new ICs, due to the previous wiring issue, but the opamps all seem to be running fine, so I'm hoping the VCAs are also unburned.  The pin voltages always read correctly.

As always, any help is highly appreciated!

ps- Gustav, I'm in USA.

Later Edit:  It also occurs to me that I have no idea what to expect this thing to sound like, really.  Does the unit usually break up with more than just a few db of gain reduction?  I see people always say they use it really lightly, but I always assumed that was because of not wanting to over-squish the mix.  It just seems to distort more than my dbx 166, which has the same THAT corp VCAs.

 

[Mazieresantoine]

Hi,
I have a problem withnmy gssl from gustav.
When the threshold is at the minimum the meter is going from 0 to 20db and then'going back to 0 and move again to 20....
When i turn the threshold at the maximum tu meter doesn't move.
I do this check without sound into the comp.
Do you have any idea?
Thanks

 

[weiss]

obviously you have some wrong wiring here - check your meter connections and all wiring of your potentiometers and the switches!

 

[Mazieresantoine]

obviously you have some wrong wiring here - check your meter connections and all wiring of your potentiometers and the switches!

Ok i will check it today I think it was maybe near the Threshold pot, because the pots for ratio/attack/release are sold on the pcb.

 

[bernbrue]

Alrighty,

So, I got passed that hurdle!  Found my mess up, and it has to do with my one main complaint, about the build guide.  I didn't see anywhere where the meter was wired in, in the assembly or universal wire guides.  I made a stupid mistake and wired the meter to the  "optional relay and light" spot, instead of the meter spot on the switches pcb.  Totally my bad, but it'd be nice if the assembly guide had the meter wired in being shown. 

Anyway, I moved those wires, plugged it in, and things seemed to be working.  The meter no longer slammed to the far side, and I went ahead and threw it in the rack.  Turned on and passed signal w/o distortion!  Makeup gain working, threshold, etc, etc, all seemed to be functioning, as intended.  Unfortunately, when the VCA kicks in and does gain reduction, I am getting distortion.  This leads me to believe that my input and output sections are good !  Yay!  Unfortunately, it seems like I'm still having a problem in the VCA sections.  It's possible that I'll need new ICs, due to the previous wiring issue, but the opamps all seem to be running fine, so I'm hoping the VCAs are also unburned.  The pin voltages always read correctly.

As always, any help is highly appreciated!

ps- Gustav, I'm in USA.

Later Edit:  It also occurs to me that I have no idea what to expect this thing to sound like, really.  Does the unit usually break up with more than just a few db of gain reduction?  I see people always say they use it really lightly, but I always assumed that was because of not wanting to over-squish the mix.  It just seems to distort more than my dbx 166, which has the same THAT corp VCAs.

Lots of  people forget to set the stopper of the release switch (only 5 positions) and get distortion.  Check it, please. The GSSL can be very subtle with moderate settings, but e.g.  set to lowest attack/release/threshold it can  compress the hell out of a drum room track.
Bernd

 

[Mazieresantoine]

obviously you have some wrong wiring here - check your meter connections and all wiring of your potentiometers and the switches!

Ok i will check it today I think it was maybe near the Threshold pot, because the pots for ratio/attack/release are sold on the pcb.

OK so it was a wrong welding in the make up pot.
But now the meter is at 4db comp (in ratio 2), and 20db comp (in ratio 4 and 10)
Thnaks for your help

 

[Mazieresantoine]

So it's not the soldering in the make up pot. I do all the wiring between make up/threshold/and bypass pot and it's the same. The meter moving from 0 to 4db in Ratio 2

 

[ding]

So it's not the soldering in the make up pot. I do all the wiring between make up/threshold/and bypass pot and it's the same. The meter moving from 0 to 4db in Ratio 2

You are making it very difficult to get help. This does not say much to anyone. Please be more specific. Set your send and return on your equipment to unity gain. Send a 1kH sine wave at -10db to both channels, no threshold and no makeup gain. Put the attack and release at medium settings. Are you getting any reduction? If you are than something else is happening, maybe with your sidechain. If not turn the threshold knob till you see 8db of reduction on your daw meters and calibrate the meter using the trim pot until the meter reads 8db. Do it again with +4db and double check. Hopefully you have a meter trim, if not it is a good mod to make. If this is not what you are describing please be more specific about what is wrong so the good people here can be more helpful. BTW this compressor is very clean and "transparent" sounding. I only get distortion when I push it hard so if you are getting distortion at low compression settings there is something wrong.

 

[Mazieresantoine]

So it's not the soldering in the make up pot. I do all the wiring between make up/threshold/and bypass pot and it's the same. The meter moving from 0 to 4db in Ratio 2

You are making it very difficult to get help. This does not say much to anyone. Please be more specific. Set your send and return on your equipment to unity gain. Send a 1kH sine wave at -10db to both channels, no threshold and no makeup gain. Put the attack and release at medium settings. Are you getting any reduction? If you are than something else is happening, maybe with your sidechain. If not turn the threshold knob till you see 8db of reduction on your daw meters and calibrate the meter using the trim pot until the meter reads 8db. Do it again with +4db and double check. Hopefully you have a meter trim, if not it is a good mod to make. If this is not what you are describing please be more specific about what is wrong so the good people here can be more helpful. BTW this compressor is very clean and "transparent" sounding. I only get distortion when I push it hard so if you are getting distortion at low compression settings there is something wrong.

Sorry for the difficult to explain.
What i see for the moment is the meter moving without sound inside. I don't have nothing plug in the comp but when i put it on the meter is moving alone.

I will try with sound inside.

 

[ding]

Ah, ok I see. And does the meter move on any other compression setting?

 

[Mazieresantoine]

Ah, ok I see. And does the meter move on any other compression setting?

Yes if i move the ratio from 2 to 4 the meter is going to 20db comp, and if i go to ratio 10, it's stay at 20db comp

 

[ding]

rule out the meter by actually running audio thru it and see if it is compressing. If its not compressing with the threshold all the way off or clockwise then it is the meter hookup or the components around the meter circuit.

 

[Mazieresantoine]

rule out the meter by actually running audio thru it and see if it is compressing. If its not compressing with the threshold all the way off or clockwise then it is the meter hookup or the components around the meter circuit.

Ok
when the comp is bypass the meter don't move, so i will check the component in the meter circuit
thanks, adn go back when i know more