GSSL HELP THREAD!!!

[somsay]

hello Barbera,

yes my unit compresses, the meter works, all my controls work.

i tried to install the turbo card for the gssl to see if i can work arround this, but i could not get the turbo card to work yet, so my left channel is louder.

i made sure i did clean soldering, i checked out the grounding, and looked at the compents again, i hope its not a faulty vca?

maybe ill try to switch my vca's too see...

 

[somsay]

i just tried to switch the vca's and they seem to do the same thing...the left channel is still louder.

 

[somsay]

i have been testing recording in mono and i actualy like the sound of the louder channel and the lower volume channel.

im gonna be using my gssl just for drums and bass. the louder channel has a cool distortion...

sounds great!

thanks all

 

[somsay]

i have been testing recording in mono and i actualy like the sound of the louder channel and the lower volume channel.

im gonna be using my gssl just for drums and bass. the louder channel has a cool distortion...

sounds great!

thanks all

 

[gyraf]

If one channel is louder than the other, this is because of one of two things.

1) Improper balancing stage, either in input or output.

1A) Balanced input: connect a balanced source, and check that level at the output of the input 5534 opamps are the same

1B) Balanced output: send audio through the unit, and make sure that you have equal output level on output xlr's pins 2 and 3, measured against ground, pin1

2) Wrong resistor somewhere in circuit - the 15K or 27K feeding the VCA's and the feedback resistors across the output opamps after the VCA's are good candidates - but follow the schematic, compare with PCB, and re-check everything in the L/R path, including the 5534-circuit around the VCAs.

...also make sure that you wired the xlr's correctly to the PCB - this is a common mistake because the numbering on the PCB in/out connector is a bit confusing

JAkob E.

 

[MartyMart]

Also check your cables, I had exactly the same issue a few weeks back and
it was a "brand new" balanced cable that was at fault !!
( lost 5db on one side )
GSSL was perfect.

MM.

 

[RedNoise]

same pb here cause of faulty solder (wiring to xlrs)

 

[somsay]

thank you kindly gyraf.

and thank your for making the gssl possible.

 

[feza]

Hey people,

Currently I am making the last order for the GSSL and then it will complete!

I've got the Purusha Oxford version of the case and need the correct toggle switch. I'm quite lost in the massive amount of switches but a SPST on-off toggle switch with solder connection and a panel mount is what I need with the Purusha case right? Still there are more things like the correct operating voltages what I do not know.

Can somebody help me with this? The last order and I can get busy! :thumb:

 

[somsay]

i got the same case, and had the same problem.

i got a 4PDT for my bypass switch so i can make the bypass led light to work too.i found no site on how to wire the poles...so i did trial and error, i didnt get it to work that well yet. if anyone knows how to wire this that would be great.
right now i got the led to work, but when i turn on my power the meter of the compressor turns on right away with the led light of the bypass...so i got it wrong...but almost right!

here is a link:
http://www.web-tronics.com/general-supplies-for-electronics-switches-miniature-toggle-switches-4pdt.html



then i got a single pole double toggle switch for the power switch. works great.
link:
http://webtronics.stores.yahoo.net/103-0132.html


good luck

 

[geetar_king]

Okay, so I'm still troubleshooting my GSSL. Problem again is no compression. Makeup gain is working fine, and unit passes clean audio.

I was reading a post about the same problem occuring on a bad connection on the bypass switch.  I just wanted to double check that my bypass wiring is correct, so I can rule that out.

I'm using a 3PDT switch. First set of poles for the compression "On, Com, Off" as on the PCB layout.  Other set of poles for defeating Makeup Gain when out. Last set of poles for the LED indicator.

I have posted a diagram of my wiring setup, added on to Gyraf's control board layout.  Is this right? I think it is, makeup works fine. Are my compression poles backwards maybe?

I'm picking up new TL074s and TL072s tomorrow to rule that out. VCAs are good. Something has to be wrong in the sidechain but what!!? I'm getting +15Vdc/-15Vdc on the rails, and voltages on the TL074 and TL072 are good at +12Vdc/-12Vdc.

Sidenote: I'm using the 2180's. What resistor value should I have for the 127K* resistor? 127K?  This mainly affects the ratios?

 

[gyraf]

Is this right? I think it is, makeup works fine. Are my compression poles backwards maybe

All is well - but you may want to add another LED for power indication - or maybe use the switch to switch in a larger series-resistor (4K7? 10K?) that is shorted out by the switch when "in", in effect dimming the LED when bypassed.

It's always nice to know if the unit is powered or not...

Jakob E.

 

[geetar_king]

Great, well its not the bypass then.  Yes, I agree about the power indicator. My next panel layout will be set up for a power indicator

 

[feza]

i got the same case, and had the same problem.

i got a 4PDT for my bypass switch so i can make the bypass led light to work too.i found no site on how to wire the poles...so i did trial and error, i didnt get it to work that well yet. if anyone knows how to wire this that would be great.
right now i got the led to work, but when i turn on my power the meter of the compressor turns on right away with the led light of the bypass...so i got it wrong...but almost right!

good luck

Thanks for the reply!

From what I know is that an SPST toggle switch is needed for the Purusha case. It only needs to powered on or the other one being bypassed. There's a LED option on the switch which will indicate when its powered/bypassed. I'll be asking this to Purusha as well. Keep on eye on this thread. 

I've found new info regarding the switches. Personally bought the relais bypass from Igor. So it might help you more :

http://www.groupdiy.com/index.php?topic=7690.0 

 

[geetar_king]

Well I figured out that my gssl compresses ONLY when either the Left or Right channel is at the input.

In stereo (both left and right IN), the unit doesnt seem to be compressing at all.

Anyone know what this solution is? Does this have to do with the 47K resistors going to the sidechain??

I've been banging my head on the desk trying to get this to compress! Hopefully that clue helps! Maybe i'll pull the two 47ks and try?

Thanks

btw, new forum search engine is muchhh better  woo!!

 

[geetar_king]

Well I upped both 47K resistors to 150Ks and nothing changed.

Decided to put the 47Ks back in, but removed one.  (the one closest to the sidechain side of the board)

I have compression in both channels now!!  Have other people done this? Is this okay to do? And would it matter which resistor i removed?

I'm not sure if thats the way to solve the problem, but I have compression now!!

 

[geetar_king]

Well I've been playing around with the 47K resistors. Thought that was my problem and they would just require tweaking?


I just noticed that on Gyraf's Rev#9 layout there are 27K resistors beside each VCA.

My board from Gustav shows 15Ks there.  I originally had 15Ks.  I'm running 2180's. Should I change these to 27Ks? What is the effect of these?

Maybe change them to 27Ks and put the 47K s.c. resistors back in?

 

[geetar_king]

Well not sure what I should be trying next.  Is there some math to determining what resistor values I should have?

Right now I have:

Positive Leg of Threshold pot: 47K

Both Summing Resistors: 47K

No noticeable compression (<0.1 dB if any) when both Left and Right channels are sent into the GSSL.

With either Just left or Just right side inputting, I get abou 8.4dB gain reduction at 10:1 ratio with threshold fully counter-clockwise.

Anyone?????????????

 

[Siegfried Meier]

Hey guys,

Just built another one of these bad boys, and I made sure that every single resistor that exists, where there's more than one, were matched identically - took some time, but I wanted to make sure that my left to right balance was perfect.  And it is, absolutely 100% perfect!

The only problem I have with the thing is that when I set my release to Auto, the whole thing distorts like mad.  I seem to recall this happening to me years ago with one, but I can't for the life of me remember what caused it, or what I did to fix it.  In every other position the thing sounds golden.  Any thoughts?

Much appreciated!!
Sig

EDIT - I just read that someone had the same thing, and that it was because they accidentally left 6 positions instead of 5 on the release.  And, that's exactly what I have.  But, the distortion sounds cool as shit!!!!!  Any problems with keeping it this way?  It's nice to be able to add it when you need it, but I'm not sure if there's any damage to the VCA's that can be caused by this etc.  Would love to know.

Otherwise, the damn thing is 100% out of the gate!!  These things get easier the more you make, I'm on #6 now.

 

[geetar_king]

Does anyone know how the sidechain input works?

Why can I get compression by panning all the way LEFT or RIGHT, but dead center there is no compression??

If I lift one of the 47K resistors, then compression works but I assume is only detected by the one side of the stereo channel.

Why am I getting compression like this?? It's weird. If I had two of these units, one for left and one for right then at least I could kinda use it  ???  Except that I dont get enough compression.

Should I leave the 47K resistors alone and play with the resistor on the threshold pot or what??