Hey all!
Many of you had helped me track down a ‘ground loop’ buzz I was having in my refurbished Adcom GFA555 amp. The buzz, was a two fold issue as it turns out!
One part was that the new inputs for the amp were not properly grounded!
So thanks to Paul and you all, I did the proper sequence listed by McGowan and found the Amp itself was making a loop…AND, the PS Audio Pre-Amp was ALSO making a buzz!!!
I hadn’t noticed, but the Pre-Amp when you plug it into an outlet, you can hear an audible ‘buzz’ from the transformer box. When attached to any amplifier, you will hear a ‘buzz’ in the speakers (low volume).
In assuming ‘well maybe the capacitors have worn out and they aren’t smoothing properly’, upon opening the case, I could see that there is a resistor (unknown value to me) that looks broken/blown a little? It doesn’t look burnt, but broken apart. Everything else ‘looks’ fine.
Would love to know the actual proper types and values of the Capacitors, the resistor, and the bridge rectifier to see about rebuilding it?
Many thanks all!
