Re: GSSL HELP THREAD!!!
« Reply #8080 on: April 13, 2019, 07:05:53 AM »
thanks weiss,
well i have some issues with unity gain due to adding a cavendish board. but that should not matter now as im running on ics atm.
there are two other things that seem dubious to me:

the ratio: when feeding a low to moderate level input 2:1 always does more reduction that 10:1. at some point (level) this flips and 10:1 actually show the most compression. reading through this thread is a pain. but from what i gathered this might be normal?

threshold: the way this sits atm i can get barely any compression when feeding a 0db sinus (as needed for meter calibration). i certainly can't get 10db of compression. there is a resistor on the control board (47k*) that supposedly reduces threshold sense. maybe jumper that?

cheers


weiss

Re: GSSL HELP THREAD!!!
« Reply #8081 on: April 13, 2019, 04:15:08 PM »
Opinions vary, but I can see at least 4 wrong resistor values in the VCA substitution blocks (the 3K9's current setting resistors for the +/-15V supplied VCAs would better be 5K1. The 68R's for the DBX2150 type VCAs should be removed/left out for your THAT2180 type VCAs.)
You -in this order- removed the nut, the washer and the indexing ring below the nut, turned the rotary switch full CCW and put back the indexing ring to the full CW position 5 for the release switch?

i changed the resistor values and reset the release switch but the release still has very little effect on the signal...
Where could i look further?

thanks for your help guys


the ratio: when feeding a low to moderate level input 2:1 always does more reduction that 10:1. at some point (level) this flips and 10:1 actually show the most compression. reading through this thread is a pain. but from what i gathered this might be normal?
yes you got to readjust the threshold when switching ratios, this is my experience as well. when i switch from 2:1 to 10:1 i need to lower the threshold otherwise, it is doing no compression. is that what you asked?

threshold: the way this sits atm i can get barely any compression when feeding a 0db sinus (as needed for meter calibration). i certainly can't get 10db of compression. there is a resistor on the control board (47k*) that supposedly reduces threshold sense. maybe jumper that?
you could try that, but i would also check for some other wiring / populating errors, as i doubt, this will have that great impact on the overall sensitivity.

weiss

Re: GSSL HELP THREAD!!!
« Reply #8082 on: April 14, 2019, 12:58:20 PM »
Could anyone tell my why I. Can’t defeat the makeup? I completely rewired the bypass switch. What could be the issue?

Potato Cakes

Re: GSSL HELP THREAD!!!
« Reply #8083 on: April 14, 2019, 05:29:33 PM »
Could anyone tell my why I. Can’t defeat the makeup? I completely rewired the bypass switch. What could be the issue?

The two solder pads shown as black dots next two the 750k resistor have to be shorted when bypassed for make up gain defeat. So however you wire your bypass switch these two pads must make a connection together some how.

Thanks!

Paul

weiss

Re: GSSL HELP THREAD!!!
« Reply #8084 on: April 15, 2019, 12:57:16 AM »
The two solder pads shown as black dots next two the 750k resistor have to be shorted when bypassed for make up gain defeat. So however you wire your bypass switch these two pads must make a connection together some how.

Thanks!

Paul

Thanks Paul,

This is mysterious. I can’t see any connection. Gotta Check continuity later.
Do i need to remove the resistor like in the picture as well?

Potato Cakes

Re: GSSL HELP THREAD!!!
« Reply #8085 on: April 15, 2019, 02:41:54 AM »
The resistor that it says to remove is the 1k for the power LED if you just use toggle switches. If you use LED push buttons you would use 1k resistor on each button's LED and not on the ratio board.

The connections on the board are unmarked but they are next to the make up gain pot connections as you can see. However you are doing your switching, whether it is toggle or relay or push button, one set of poles somewhere has to make that connection between those two pads when you bypass the compressor. You may even have to add a relay or a switch with more poles to do this. But that is how you do make up gain defeat for the GSSL unless you add a hardwire bypass on all of the XLRs.

Thanks!

Paul

weiss

Re: GSSL HELP THREAD!!!
« Reply #8086 on: April 15, 2019, 09:29:37 AM »
The resistor that it says to remove is the 1k for the power LED if you just use toggle switches. If you use LED push buttons you would use 1k resistor on each button's LED and not on the ratio board.

The connections on the board are unmarked but they are next to the make up gain pot connections as you can see. However you are doing your switching, whether it is toggle or relay or push button, one set of poles somewhere has to make that connection between those two pads when you bypass the compressor. You may even have to add a relay or a switch with more poles to do this. But that is how you do make up gain defeat for the GSSL unless you add a hardwire bypass on all of the XLRs.
Again thank you, paul.
I checked for continuity at the pads and noticed something weird.
When i check between both pads i can break the connection with the switch, but when i check between the pads and the middle leg of the makeup potentiometer there is always continuity which explains my problem! but there is no connection between the potentiometer and the pads.... is the pot broken? or the switch? what am i missing ???

weiss

Re: GSSL HELP THREAD!!!
« Reply #8087 on: April 15, 2019, 12:43:13 PM »
Now i replaced the whole control board and the makeup gain works correctly. I don't know what the problem was. Am gonna trash the old board...

thanks for your help!

weiss

Re: GSSL HELP THREAD!!!
« Reply #8088 on: April 16, 2019, 10:08:37 AM »
i want to avoid the super sidechain board and use a rotary switch to use different frequencies for the hpf like in this picture:


Is it correct that i combine the two 47k resistors, connect this to my SW pole and then on each lug connect the corresponding cap and wire it to the other end of the 47k resistors?

any help would be appreciated.

thanks

Harpo

Re: GSSL HELP THREAD!!!
« Reply #8089 on: April 16, 2019, 10:54:36 AM »
Is it correct that i combine the two 47k resistors, connect this to my SW pole and then on each lug connect the corresponding cap and wire it to the other end of the 47k resistors?
No. (this would make it a mono compressor with fighting left/right side).
Your switched caps ensemble connects between TL074/pin7 (the output of the current to voltage converter) and the following DC-blocking 22uF/35V cap. This further goes to the two 20k input resistors of the full wave rectifier, each connecting to a virtual ground node, so the resistive part of the -6dB slope R/C HPF is the paralleled value of these=10K.  The HPF cutoff point is set by 1/(2xPI() x R x C) with R in Ohms and C in Farad. Keep in mind, this is NOT an external input as this would be breaking the sidechain-VCA/rectifier/timing control-loop.
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams


weiss

Re: GSSL HELP THREAD!!!
« Reply #8090 on: April 16, 2019, 11:35:31 AM »
No. (this would make it a mono compressor with fighting left/right side).
Your switched caps ensemble connects between TL074/pin7 (the output of the current to voltage converter) and the following DC-blocking 22uF/35V cap. This further goes to the two 20k input resistors of the full wave rectifier, each connecting to a virtual ground node, so the resistive part of the -6dB slope R/C HPF is the paralleled value of these=10K.  The HPF cutoff point is set by 1/(2xPI() x R x C) with R in Ohms and C in Farad. Keep in mind, this is NOT an external input as this would be breaking the sidechain-VCA/rectifier/timing control-loop.
harpo! you are the man ! this works like a charm. i tried it between the resistors before but the effect wasn't pleasant.
Now this thing is absolutely perfect. thank you very much!  :)

Re: GSSL HELP THREAD!!!
« Reply #8091 on: Today at 12:32:45 PM »
Hi all,

Build myself one of those Gyraff Audio GSSL comps.
Everyhging works within a certain range of the settings but the unit behaves bad @ higher copression.

When I turn the threshold down slowly and I receive more and more compression @ a certain level (around 10db) of compression the needle jumps all the way to maximum compression and the unit goes silent for a brief moment. Then the sound returns @ the speed set by the release.

Every control element on the panel works but once I hit a certain amount of compression the thing goes TILT.

On a typical drum loop this happens every 2 snaredrums or so.

Any ideas?

Thanks in advance.

weiss

Re: GSSL HELP THREAD!!!
« Reply #8092 on: Today at 12:57:23 PM »
Hi all,

Build myself one of those Gyraff Audio GSSL comps.
Everyhging works within a certain range of the settings but the unit behaves bad @ higher copression.

When I turn the threshold down slowly and I receive more and more compression @ a certain level (around 10db) of compression the needle jumps all the way to maximum compression and the unit goes silent for a brief moment. Then the sound returns @ the speed set by the release.

Every control element on the panel works but once I hit a certain amount of compression the thing goes TILT.

On a typical drum loop this happens every 2 snaredrums or so.

Any ideas?

Thanks in advance.


I had a similar problem with one of my units. Did you check voltages? What VCA's are you using?

Potato Cakes

Re: GSSL HELP THREAD!!!
« Reply #8093 on: Today at 01:39:34 PM »
Hi all,

Build myself one of those Gyraff Audio GSSL comps.
Everyhging works within a certain range of the settings but the unit behaves bad @ higher copression.

When I turn the threshold down slowly and I receive more and more compression @ a certain level (around 10db) of compression the needle jumps all the way to maximum compression and the unit goes silent for a brief moment. Then the sound returns @ the speed set by the release.

Every control element on the panel works but once I hit a certain amount of compression the thing goes TILT.

On a typical drum loop this happens every 2 snaredrums or so.

Any ideas?

Thanks in advance.

Double check your components and solder joints, especially on and around the header that connects to the control board. Also check the wiring from the main PCB to the control board. My first GSSL had a pair of wires crossed there and a solder bridge on that header which caused it to malfunction.

Thanks!

Paul


 

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