[Arny Krueger]

"jamesgangnc" wrote in message


I see nothing that looks like any sort of regulation in
this amp.

That is typical.

The scratchy noise is on both channels but it is not
identical. Given that there is hardly any common
components makes it a bit strange. There are a number of
wire wraps on the pwer supply. I have encountered age
related issues with wire wraps in other amps. (I have a
sx-1250 that had a low output problem on one channel that
was fixed by simply soldering the wire wraps. That amp
has the output transistors connected to the main board
with wire wraps.) This adcom does not have any wire
wraps in the output circuitry but there are some on the
power supply board. And a few on indicator leds. No
hard in soldering those.

Go for it!

I think the next step for me is to check the rectifier
bridges for shorts.

Unlikely, as shorted power supply diodes always blow fuses and the like.

Open diodes is more likely.

Replace the filter caps since they
are 20 years old anyway.

Don't jump to conclusions.

Solder all the wire wraps.

Agreed.

The unit does share a common ground throughout and one
side of each output channel is at ground. I have not
checked to see if one side of the input is ground but
expect it is.

There might be some low value resistors in that path, or the path may be
through one circuit board.

The power cord does not connect to the
mains ground.

Normal.

There definitely could be something to the
ground issue idea.

Please keep us informed!