GSSL HELP THREAD!!!

[drive]

The compression kicks in to late, I have to turn the threshhold to at list 9 o'clock for the comp to start compressing. What would I need too change for it to start compressing sooner?
I tried to change 47K on the threshhold but that does not seem to do much.

 

[Autophase]

right i just had my first power on without any of the IC's plugged in, the power light is on which is a good sign. but it wont turn off when i flick the power switch.
What could cause this?

Also when checking the DC voltage on the board I'm getting 31V, I know this cant be right. Any suggestions.

 

[Biasrocks]

right i just had my first power on without any of the IC's plugged in, the power light is on which is a good sign. but it wont turn off when i flick the power switch.
What could cause this?

What won't turn off, the LED or the entire unit?

Also when checking the DC voltage on the board I'm getting 31V, I know this cant be right. Any suggestions.

Are you checking the +/- rails togther? That would give you 30VDC or so, if so you're fine as far as voltages go.

To measure the power rails properly, you should be referencing it to ground.

Mark

 

[jeandoe]

Hey everybody

Alright. After loads of fault finding i had everything working nicely. However the last two weeks I started experiencing distortion problems that seem to increase in quantity. It started with the ration switch, which caused gross distortion after changing positions. This would be solved by randomly adjsuting any of the knobs ??? ??? Now the problem started appearing with practically all changes of position with any knob! What did seem to help was to turn them really really gently  ???
The distortion seems to be a lot worse at the highest ration setting where it also introduces a strange tonal ca 4k crunchy hiss.

Any ideas where i could start looking?

Much appreciated,

Joel

 

[Autophase]

right i just had my first power on without any of the IC's plugged in, the power light is on which is a good sign. but it wont turn off when i flick the power switch.
What could cause this?

What won't turn off, the LED or the entire unit?

Also when checking the DC voltage on the board I'm getting 31V, I know this cant be right. Any suggestions.

Are you checking the +/- rails togther? That would give you 30VDC or so, if so you're fine as far as voltages go.

To measure the power rails properly, you should be referencing it to ground.

Mark

Thanks mark, I was measuring both, referencing ground its fine, thanks for that.

As for the LED thing I dont know if its just the LED or whole unit, I havent solderd on my audio inputs and out puts or potentionmeters yet. all I know is the lLED is on when the power switch is set to on and off.

 

[signalflow]

Hello all,

I've had my GSSL up and running for awhile now and it is absolutely wonderful.  But one thing I'm experiencing and was wondering if anyone else had the same problem is that If I just put it on a 2 trk mix, either drum or full mix, I have to have my threshold wide open and bring my signal down from my mixer just to not have it start slamming the hell out of my tracks.  It acted this way before I added in the turbo function so it's not that doing it.  Do I just need to play round with values of the threshold sensitivity resistor?  Or is there something else that should be looked at?

Thanks

-Casey

**EDIT**  I missed this thread on my search earlier it seems that some issues were sorted out with some resistor swaps.  I'll trythem out and see.
http://www.groupdiy.com/index.php?topic=2418.20

 

[Biasrocks]

As for the LED thing I dont know if its just the LED or whole unit, I havent solderd on my audio inputs and out puts or potentionmeters yet. all I know is the lLED is on when the power switch is set to on and off.

When you switch it off do you still have +/- 15VDC?

If so, perhaps you're switching the neutral side of the power connector or some other thing.

How do you have it wired coming from the outlet into the power transformer?

Check this for a reference.

http://sound.westhost.com/psu-wiring.htm#s2.0

Mark

 

[Autophase]

As for the LED thing I dont know if its just the LED or whole unit, I havent solderd on my audio inputs and out puts or potentionmeters yet. all I know is the lLED is on when the power switch is set to on and off.

When you switch it off do you still have +/- 15VDC?

If so, perhaps you're switching the neutral side of the power connector or some other thing.

How do you have it wired coming from the outlet into the power transformer?

Check this for a reference.

http://sound.westhost.com/psu-wiring.htm#s2.0

Mark

I have the transformer primary plugged into the mains. and the secondaries connected to the 3 pins on the main GSSL board.
The switch I'm referring to it the rotary switch on the control board

 

[wmtunate]

As for the LED thing I dont know if its just the LED or whole unit, I havent solderd on my audio inputs and out puts or potentionmeters yet. all I know is the lLED is on when the power switch is set to on and off.

When you switch it off do you still have +/- 15VDC?

If so, perhaps you're switching the neutral side of the power connector or some other thing.

How do you have it wired coming from the outlet into the power transformer?

Check this for a reference.

http://sound.westhost.com/psu-wiring.htm#s2.0

Mark

I have the transformer primary plugged into the mains. and the secondaries connected to the 3 pins on the main GSSL board.
The switch I'm referring to it the rotary switch on the control board

That's not a main power switch.  It's a compression enable/disable switch (or "bypass" as it's labeled in the documentation).  You NEED to put a switch between the primary of the transformer and the AC input from the wall, otherwise everything is powered up as long as you have it plugged in, as indicated by your LED.

 

[Autophase]

That's not a main power switch.  It's a compression enable/disable switch (or "bypass" as it's labeled in the documentation).  You NEED to put a switch between the primary of the transformer and the AC input from the wall, otherwise everything is powered up as long as you have it plugged in, as indicated by your LED.

Ah ok thanks, I'll probably just get a switched IEC socket.
I'm still a little confused with  the rotary switch on the control board that switches compression in and out, on the files on the gyraf site it shows more wires connected to it than just the the 3 wires that go to "on" "off" and "com" is it essential for me to connect these, also there is  a small jumper on the control board labelled "a" and "a2" am i supposed to jumper this? What does it actually do.

Thanks

 

[radiance]

Ah ok thanks, I'll probably just get a switched IEC socket.
I'm still a little confused with  the rotary switch on the control board that switches compression in and out, on the files on the gyraf site it shows more wires connected to it than just the the 3 wires that go to "on" "off" and "com" is it essential for me to connect these, also there is  a small jumper on the control board labelled "a" and "a2" am i supposed to jumper this? What does it actually do.

Thanks

Wire the rotary as described in the gyraf docs. If you only wire the on off com wires your make up gain pot will always be active, also in bypass mode. I've no idea what these a and a2 jumpers are...must have been added on newer version pcb's than I've laying around.
Post a pic maybe..?

 

[pearldrum944]

I have a couple of new questions.  

I just looked up directions for testing the pots tonight, so did not get a chance to check them today...but in 2:1 the compressor is compressing with the threshold fully CCW.  Also, with the make-up gain fully CCW I am getting a level increase of 4 or 6 db.  Think these problems are related?  Other than this, these knobs appear to work properly.
EDIT: No worries, I finally found out good search terms for these issues.

 

[gerardmanvuca]

There are some questions and info regarding the DBX 202 Black Cans and GSSL compatibilty here:

http://www.groupdiy.com/index.php?topic=37306.0

 

[pietro_moog]

hi guys!
i finished my gssl, i tried without turbo board and it was working.
i installed the turbo board, but i didn't tried it because it was late and i was tired.
i'll check the sound tonight.
my problem is my power led doesn't work anymore..
i soldered the turbo wires on the switches pcb, but maybe i did not a god job. (it was late)

do you guys know which connection powers the led?

thanks




p.s.
is it normal that 78L12 and 79L12 runs at a super hot temperature?
i thought that 7815 and 7915 should be hotter, instead 78&79L12 are.
i mean so hot that you can light a cigarette with..

 

[livingnote]

In that case the 12's were pumping too much current, got hot and folded back (though
I don't know if the little ones do that too...) but that'll put out your LED because
of the volage drop/current limitimg.

Might wanna check to see who's the culprit sucking all that current, either it's a short
or a component that's doing the krazy straw...

 

[gerardmanvuca]

Weird thing on my GSSL...its al working great with DBX202's, turbo and sidechainboards. But when i run my sound card inputs at -10dB the left channel is a few db louder than the right.....when i run the soundcard at +4db the levels are spot on equal.    Any one have any ideas?....i'd rather run at - 10db than +4  so i can push the gssl a bit more

 

[pietro_moog]

thanks livingnote,
i thought something like this, but i was not sure. so, if the comp seems to work fine, how can it has a short or a component working bad?
and how can i check it?  i checked all the voltages on the main pcb before installing SSC board and turbo, and everything was ok.
 
thanks

 

[Biasrocks]

and how can i check it?  i checked all the voltages on the main pcb before installing SSC board and turbo, and everything was ok.

The turbo board is using the 12v supply iirc. You may have a problem there, component shorted, etc.

Try disconnecting the Turbo board from the power supply to see if the regulators cool off. You could also monitor how much current the Turbo board is drawing by placing a 10ohm resistor in series with each power rail (+/-) and measuring the voltage across the resistor. See this post for more info.

http://www.groupdiy.com/index.php?topic=37348.msg459858#msg459858

If you find no shorts you may want to check how much voltage are you throwing away at the 12 volt regs. If it's a significant amount that may explain why they're heating up.

You can measure the voltage at the junction of the 10R resistor and the 22uF capacitor just ahead of the regulator.

Mark

 

[pearldrum944]

My compression kicks in too early.  With a -10dbfs input tone, I am getting 2db of compression in a ratio of 2:1.  I know how to adjust the threshold sensitivity.  But how do I raise the whole range?

 

[livingnote]

@pietro - exactly, like Mark says - you can have some kind of phenomenon where there
is not enough voltage or current to fodder the LED but still holds up the sidechain opamps
somewhat because they have low current draw and are happy below 12V too (though
this could give you some weird compression behavior you don't notice at first if the SC
does hit the rails).

@Pearldrum, 10 dBFS bears no indication re how that translates to how many dBu now
actually are coming out of your DAC at the end, your comp could be doing just fine while
your DAC is firing a bit high. The sensitivity adjust thing with the resistor does both, changes
sensitivity AND bumps the range up, but before I'd twiddle that I'd check to see how many
dBu are coming out of your DAC at -10dBFS to know what's going on (1kHz tone and
AC volt meter). You can translate this on this thing