Adcom GFA 4304 amplifier


2008-02-28 2:14 am
Just wondering if anyone out there is in ohio area and is able to repair my amplifier.I'm not too sure what happened,but I suspect a little water got inside the amp and caused the problem with it.Upon power up one of four channels causes severe popping in connected speaker,has a real pungent odor,output maybe?No major signs of burning on circuit board.This has been my favorite amp for nearly 14 years,first problem.Any help would be greatly appreciated.

Perry Babin

Paid Member
2003-11-20 11:01 am
A pungent odor would tend to be a resistor or a transistor.

A sweet odor would tend to be electrolyte. This is more likely to cause a popping sound through the speakers. If the problem is leaking electrolyte, you should have the repair shop replace all of the caps similar in construction to the one that leaked. If one has leaked, the rest will be likely to leak also. If the large, snap-in filter caps are intact, they probably don't need to be replaced.
I own 6 of these.
As I recall Adcom will still service these, but that was some time ago when i heard this info. But you can goggle Adcom and call them and ask...

I take care of my own, and stock all original parts for these, They require gain matched Mosfet devices throughout the entire amp circuit, as I recall Adcom used to advertise 2% gain matched devices inside them.

I have seen a few failures over the years, mostly the input mosfet pair,and or a output or two, and turn on circuitry failure on some older models < just a couple bipolar transistor in the turn on circuit and viola! she lives again.
If your getting it fix, I recommend capacitor replacement inside the amp due to age and length of service. I did mine and actually increased the internal energy storage by 50% of that Adcom used to talk about in there sales ads... Hope this info helps