wthrelfall
Well-known member
I cleaned up the flux and checked the suspected short, installed a new rectifier and switched on: exactly the same results as before - rectifier burned out.
Harpo said:
GSSL HELP THREAD!!!
- Thread starter hairyandy
- Start date
Help Support GroupDIY Audio Forum:
Chrome Heart
Well-known member
wthrelfall said:
Check the bottom of the CRC board and make sure there is no shorting.
Chrome Heart
Well-known member
On another note, I cant seem to fing the problem on this comp. Ive check everything voltage wise and it seems to be right. The unit is not compressing and in bypass mode the meter pins.
Any ideas?
Any ideas?
Chrome Heart
Well-known member
Does anyone know if there is supposed to be 12v DC on the plus leg of the makeup gain pot?
Chrome Heart
Well-known member
Yes, I found the schemo and saw that.
Chrome Heart
Well-known member
Well, the unit is not compressing. No audio passes in bypass and the VU pins in bypass. I get audio in comp mode but no functions work.
Chrome Heart
Well-known member
Well its passing audio now. I had a cooked TL074. Makeup gain works but still no comp.
Harpo
Well-known member
you checked the maybe broken from reverse bias 22uF at TL074 pin7 ?
you swapped the sidechain VCA with an audio VCA to exclude this part being broken ?
you swapped the sidechain VCA with an audio VCA to exclude this part being broken ?
Chrome Heart
Well-known member
Harpo said:
Harpo said:
Yeah. I replaced the 22uf @ pin 7 with a new one. I also replaced the VCA's on the in and out. Ive built 4 of these so I have a bunch of parts around. Im not sure where else to look. I also replaced the diodes in the TL074 part of the circuit thinking maybe they popped at the same time as the OpAmp. No go.
Harpo
Well-known member
a TL07x isn't that easy to kill. Opamp might have been latching to a rail voltage when running open loop because of an oxydated socket that didn't make contact to the chip. Reseating or pulling chips out of their socket and back in often helps enough to scrap this oxydation layer off contacts.
Chrome Heart
Well-known member
Thanks Harpo. I replaced all the chips because I had a bunch. No luck. So far, Ive all but rebuilt the dang thing.Harpo said:
Make sure that your bridge rectifier has the correct pinout (!!!)
99% of ROUND bridge rectifiers are correct when you orient the +pin correctly - but the square types can have any pinout (ac,ac,+,-) and WILL burnout if wrong
Jakob E.
99% of ROUND bridge rectifiers are correct when you orient the +pin correctly - but the square types can have any pinout (ac,ac,+,-) and WILL burnout if wrong
Jakob E.
wthrelfall said:
wthrelfall
Well-known member
Jakob, thanks for the reply. Yes, I checked this already, but of course I'm going to check and double check again..
Last night I actually had a dream about the compressor working... perhaps today we will solve it!
Last night I actually had a dream about the compressor working... perhaps today we will solve it!
gyraf said:
Harpo
Well-known member
You have a short somewhere in between the positive raw DC and 0V. There are only 3 parts in this area. The (maybe broken) 1000uF cap next to the rectifier, the (maybe broken) 7815 voltage regulator and the (maybe shorted) pcb trace linking these parts. Until you remove this short circuit, you will blow your rectifier again. Use a magnifying glas to spot a short between pcb traces, double check the regulator is a 7815 for real, not a 7915 or whatever else. Ohm it out for a higher ohm reading before soldering the next rectifier on pcb. A low/zero ohm reading will indicate, there is still a short.
checked without success ,
about possibility
to set the gssl attack and release controls as " fine " variable , like threshold and make up do ,
leaving the rotary switches and adding a potentiometer for fine regulation
there is some help about ?
peace
r2d
about possibility
to set the gssl attack and release controls as " fine " variable , like threshold and make up do ,
leaving the rotary switches and adding a potentiometer for fine regulation
there is some help about ?
peace
r2d
Harpo
Well-known member
??? my last answer to this subject was two pages back in this thread. There are others as well.r2d2 said:
thanks Harpo !
i checked about the first 100 pages and some research too by search function
... o my god this thread is the largest of all the other ...
some "direct link" about all gssl "options-add on" posted in the first page of this thread
would be a nice great help ,
peace and diy !
r2d2
i checked about the first 100 pages and some research too by search function
... o my god this thread is the largest of all the other ...
some "direct link" about all gssl "options-add on" posted in the first page of this thread
would be a nice great help ,
peace and diy !
r2d2
Harpo said:
wthrelfall
Well-known member
Harpo, you are right - there was a short in chef's pcb, from the + to the ground just after the rectifier - a really tiny piece of copper (I took a photo in case others have this problem, it's about halfway between the rectifier and the capacitor). So thankyou Harpo & Jakob for helping...
But! I have correct voltages everywhere and I can pass signal when in bypass, but no sound when compressor is 'on'.. here we go again :-[
But! I have correct voltages everywhere and I can pass signal when in bypass, but no sound when compressor is 'on'.. here we go again :-[
Harpo said:
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