Almost 24 hours TO THE MINUTE since this problem mysteriously appeared, it
vanished!

I had pulled the amp from the rack 20 minutes ago, leaving slack on the
wiring enough to set it on a crate in front of the rack. I powered it up and
it worked normally.

So the next thing I do is take an alligator lead and cautiously touch the
amp chassis with one end and the rack with the other, fully expecting
fireworks. Not a thing happened.

So the next thing I do is carefully lift the entire amp and sssllooooowwlly
slide it into the rack space where it normally sits. Again, NOTHING unusual
happens. So now I'm really wondering... The next thing I do is put one screw
in. Still no fireworks. I put the rest of the screws in. It's still working!

Next test: I power off the amp and power it back on. Still works.

Now let's try the other surround source (at this point I have it working
with the front end mixer output, something it would not do for the last 20
hours.) I swap the input connections with the output of the DVD player's
surround outputs. I power the amp up and... no popping. Just surround
program coming out of both channels as it should.


The bottom line is, this goes down in my "X-Files" folder. It's something I
cannot explain. For exactly 24 hours, no matter what I did, I could not
solve the "feedback loop" or whatever phenomenon was occuring. Now it's
working and all I did was install the amp while it was powered on. The other
7 or 8 times I installed it in the last 24 hours it was powered off. Go
figure. I'm not a mystical man, but this occurance is deeply disturbing
because I have not found the cause of the problem, and it cleared up just as
quickly and mysteriously as it appeared last night.