my 11 year old parasound HCA-220 seems to be have a problem. When I first turn my system on, the speakers fade out and I get some static. after 10-15 minutes (once the amp is warmed up?) everything is fine. I first thought the problem was my preamp/processor but parasound checked that out and said it was fine.

I could tear apart my HT and hook up my other 5-channel amp to my main speakers and if everything is fine then that would tell me my main HCA amp is the problem but frankly that is a major headache for me to do with the cabinetry etc...

any suggestions?