DIT amp schematics ADCOM GFA585 rebuild?

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vincent_brient

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Joined 2005
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#1
Hi,
I am using a GFA585 for my subwoofer. I have only one channel working, but with an unstable offset. I don't have any more the other channel. A few minutes ago it completely died, some small signal transistors and resistors burnt. This one-channel GFA585 was already modified (protection removed...) so the pcb is a mess, with an offset problem and now many components burnt.

So I would like to use the existing case, +/- 90V power supply, heatsink, output transistors etc.. to build a new one-channel high power amplifier.
This amplifier used 5 pairs of bipolar transistor 2SD424 and 2SB554.
Who can give me a new and simple schematics that I could build to replace the Adcom PCB?
Or should I buy a PWM amplifier module and place it in the case? In this case I would not use the output transistors.

Vincent
 
#2
I had rebuilt my GFA-585 input boards. They too were a mess. The caps leaked electrolite all over the boards. If the traces are not destroyed you would be best off cleaning the boards. You will need an ultrasonic cleaner, and use a 10 to 1 misture of simple green. If intereseted I can point you to my thread.
Ben
 
#5
I found that gfa565 shematic is much diffrent than gfa585. I down loaded from googling gfa585 and forgot the link. GFA585 schema I got from internet was much better resolution, and is correct one for gfa585 than gfa565 I got from one of Adcom thread here. If you can not find it, i can email to you

Can somebody tell me what brand electrolytics they used on GFA585. My gfa 585 had really bad repairs by Frankenstain. Rt and Lt has no matching caps on value and brands.
 
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#6
birdyman said:
I found that gfa565 shematic is much diffrent than gfa585. I down loaded from googling gfa585 and forgot the link. GFA585 schema I got from internet was much better resolution, and is correct one for gfa585 than gfa565 I got from one of Adcom thread here. If you can not find it, i can email to you

Can somebody tell me what brand electrolytics they used on GFA585. My gfa 585 had really bad repairs by Frankenstain. Rt and Lt has no matching caps on value and brands.
Click to expand...
hello i need a higher resolution scema for the gfa585le thanks ken
 
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