GSSL HELP THREAD!!!

[weiss]

hey all, any idea why my unit would be distorting audio at the fastest release setting but all other are fine? comp sounds and works perfectly otherwise, just distorts at .1 release setting.

what music are you playing through it ? what type of distortion?

to some extent, distortion or rather "saturation" at lowest release setting is normal

 

[Catrunes]

what music are you playing through it ? what type of distortion?

to some extent, distortion or rather "saturation" at lowest release setting is normal

Different program material, all same result. even when throwing pink or a low 1k sinus through it distorts. sounds like 3rd order but i havent put my analyzer to it yet. will be able to tomorrow.  its definitely not typical. ive built 2 of these before no problems.

 

[Gustav]

Hello, I build the Gssl toghter with the super side chain from PCB Grinder and the push bottons from Don Audio too.
But I do not know the right wireing. Can you helt me, do you have any layout? Many thanks

Doing mods and adding to the design adds variables. If you are not able to figure out the wiring of a switch, its best to leave out that variable. Then, when you add it to a known-to-be-working circuit, you can do a bit of trial and error to achieve what you want, knowing that the basics work.

So, here comes my broken record..

"Do the basic build first".

Gustav

 

[Potato Cakes]

Hello,
I am new here and I have more mechanical background then electronical.
But in the past I positive results ;-) At the moment I build from PCB Grinder the GSSL kit together with the Super Side Chain PCB.
I buy the housing kit from Don Audio including push buttons.
The PCBs are done, now I want connect these boards together but it is not clear for me how I should connect the push buttons together with the "control unit", the mean board and the Super Side Chain PCB.
I found in the net differed of pictures, layout etc.
Can anybody help me? Many thanks

Do the one on the right.

 

[Gustav]

What should I do with this kind of feedback? I need a way to solve the problem , on my pictures there are layouts but these are not fully clear for me! Maybe you have a real solution for me ;-) THANKS

I do not have a detailed answer to your modified wiring, thats better than your drawing, unless I spend time doing the work figuring it out. Even then, I do not have the switches you want to use to check it out - you do!

What I recommend  is what I would do myself. Cut out variables by doing the basics, then add the modification, knowing that the modification is the only variable at play. That way, you can move things around a bit and apply logic to your problem solving, even gain some understanding.

I have helped hundreds of people with their GssL unit - I guarantee you that one of the most important lessons learned it, that its nearly impossible to help unless they get the "basics" working first.

Asking for a real answer makes me feel like you are uncertain wether you will be able to do the modifications you would like to do without a detailed roadmap drawn for you. I have no doubt you can get there, based on my advice, if you get basics working first.

Gustav

 

[Potato Cakes]

Who can help me?
GSSL from PCB Grinder together with the Super Side Chain Board and two Push Buttons from Don Audio.
I need the right wiring ;-) Thanks for your support ;-)

First, all questions regarding mods and add-ons need to posted on the GSSL Add-On thread to keep this already very lengthy thread from exploding. Second, both times you had posted images that have all of the information you need. The SSC board has connections on it for the bypass switch and LED for said bypass switch. I'm not sure what you want anyone here to do as you seem to have all the information you need. Look over the images you've posted and you'll soon be able to figure it out.

Thanks!

Paul

 

[SeanRyderWilliams]

Hi All - This is a great thread, and has been more helpful than SSL in diagnosing my original FX-G384 Grey Face with THAT 2002T VCAs and LF356N ICs.

I'm hoping some here may take pity on me and offer some suggestions, any suggestions on troubleshooting and diagnosing this G384...

-Originally the issue started with an intermittent short in the right channel that seemed to be affected by turning the ratio switch... Though now, and maybe through my troubleshooting, the Compressor does not seem to engage.

I have done extensive testing, please see results...

Again, Any and all feedback and advice is welcome...I've been pulling my hair out and testing for weeks...Trying to finish mixing a labor of love before I run out of money and time and this is my mix bus compressor.

I have more / better test result pics here... https://www.gearslutz.com/board/geekslutz-forum/1247336-i-m-diagnosing-ssl-compressor-issues-please-advise-ssl-gssl-etc-rack-compressor.html

Sincerely,

- Sean Ryder Williams

 

[Potato Cakes]

Hi All - This is a great thread, and has been more helpful than SSL in diagnosing my original FX-G384 Grey Face with THAT 2002T VCAs and LF356N ICs.

I'm hoping some here may take pity on me and offer some suggestions, any suggestions on troubleshooting and diagnosing this G384...

-Originally the issue started with an intermittent short in the right channel that seemed to be affected by turning the ratio switch... Though now, and maybe through my troubleshooting, the Compressor does not seem to engage.

I have done extensive testing, please see results...

Again, Any and all feedback and advice is welcome...I've been pulling my hair out and testing for weeks...Trying to finish mixing a labor of love before I run out of money and time and this is my mix bus compressor.

I have more / better test result pics here... https://www.gearslutz.com/board/geekslutz-forum/1247336-i-m-diagnosing-ssl-compressor-issues-please-advise-ssl-gssl-etc-rack-compressor.html

Sincerely,

- Sean Ryder Williams

You would be best served starting a new thread specific to the SSL unit. To keep things under control on this one, only questions pertaining to a stock GSSL build should be posted here. It'll help keep things less convoluted.

Thanks!

Paul

 

[erquere]

Hi ! I have one trouble with my GSSL - PCBs bought at pcbgrinder. The internal sidechain doesn't seem to work, I checked components everything seems fine, wiring seems fine, it compresses a lot when the SC is off, and nothing when on. Any idea ?

 

[weiss]

Hi ! I have one trouble with my GSSL - PCBs bought at pcbgrinder. The internal sidechain doesn't seem to work, I checked components everything seems fine, wiring seems fine, it compresses a lot when the SC is off, and nothing when on. Any idea ?

hi,

are your voltages correct? check your sc and bypass switch wiring again.

 

[erquere]

The SC 2181B is 10V and -7V fed, signal seems very low : 3mV

Could the SC switch type have consequence ? ON-ON or ON-OFF ?

 

[gyraf]

The internal sidechain doesn't seem to work,

it compresses a lot when the SC is off, and nothing when on. Any idea ?

Not much in that part of the circuit.

We know it works when sc filter is set to off, that is, your blu+red wires (in above pic) shorted. But not when there is a capacitor (the one mounted on the switch) in that circuit.

Could be two things then

- capacitor way too low value, giving way too high a highpass (re-read marking, or test again with very-high frequency signal) or
- switch/soldering-to-switch not working (test with beeper)

Jakob E.

 

[erquere]

SC filter cap was too big in voltage... now it works. A thousand thanks Jakob !

 

[dasnevestheo]

Hi everyone,
After reading all 400 pages I don't think my problem as already been discussed here...
Everything looks fine except threshold is fixed (quite low, it always smashes the signal).
but it behave quite strange, it's not really changing the threshold of the compression but more like adding a DC signal to the sidechain CV... Very hard to explain so i made a video : https://drive.google.com/file/d/1Fo1k_nbC3phl1Wwg7GkuNoNH4yZNxa-J/view?usp=sharing  please note that there is no signal plugged in during this video so you can notice how the needle is moving by itself when tweaking the threshold knob. You can see on the scope whiper from the threshold pot going from -12 to +12.

Since i can't even put into words what's going on it is really hard to troobleshoot
Any clues ?

Thanks a lot everyone !

 

[Potato Cakes]

I've had something like this happen. It had to reflow and solder joints and make sure I didn't have solder bridges. So unfortunately you get to spend a some quality time looking for a bad connection. You also might need to swap the two chips in the side chain.

Thanks!

Paul

 

[dasnevestheo]

Thanks Paul
Indeed it looks like pin 4 (+12) of TL074 is shorted to pins 3 and 5. pins 3 and 5 are supposed to but not 4. Let's dig in !

 

[dasnevestheo]

SOLVED
turns out the light bulb i was using has an internal resistance so low (13ohms) it was sucking all the current, almost shorting the 12V rail to ground
Should i just add a current limiting resistor to the light bulb ?

 

[Potato Cakes]

I've noticed a strange this with mine recently. It seems that when in bypass it emits a 2k or so tone but it totally fine with the compressor engaged. It does have some mods to it, but all of those work just fine with the circuit in. It's just a little curious to me that with less things in circuit, it develops this problem. Obviously I just leave the compressor turned on and I don't think about it, but I am curious to what it could be in case one day I decide to pull it out of the rack and look try to find the culprit.

Thanks!

Paul

 

[gyraf]

Paul,

Bypass only does two things: Disconnects signal from rectifier into attack/release timing (thereby stopping gain reduction) and disconnecting the makeup gain pot's DC that is added to the main VCA.

If you get noise in there on bypass, not when active, these are the places to look. To clean up the bypass by grounding unused ends when bypassed, look at how it's done in Harpo's schematic, attached.

But usually it shouldn't be necessary, unless you have some noise source in there with the pcbs. Does your noise change when you move wires and cables around inside?

Jakob E.

 

[Potato Cakes]

Jakob,

Thanks for the schematic. I've stashed it away for safe keeping.

I haven't gotten so far as to listen and mess with the wires to see if it goes away. My thought was that it's fine with everything in circuit, what could be induced to the signal with the sidechain bypassed? I've not had this issue before with other GSSL's I've built even with add on boards. When I discovered the issue I had just put it back in my rack after fixing the XLR connections (again, this was my first GSSL build that was used for experimenting), and I needed to keep working on the project at hand so I didn't worry about and just left the compressor engaged. It may be related the make up gain defeat connection now that I think about it as I know the soldering in that region of the control PCB is a bit scary after all of the work that has been done on it. When it get back to doing a full tech day in the studio I'll look at it.

On a side note, I get a similar noise out of a preamp and I had thought it was the DOA but it still made the noise without one installed. I do have to fix that one sooner than the GSSL, so I'm wondering if it is electronically related.

When I find the culprit I'll let you know.

Thanks!

Paul