I also have an old GFA-555 that still sees action and it has always that has always done the squiggly sound thing at shutdown. I was also told by Adcom that it is normal. If I remember correctly lowering the volume seemed to make it less obvious. I just leave mine on 24/7 anymore so the squiggle is gone.
amp make discharge noise
Every time I turn off the amp, I get a discharge noise. I have a Adcom GFA-545 II. Does anyone have similar problem with this model? thanks alot