I don't understand a problem with my amp.

I own an EAD 1000 amplifier. I have fed it with both a Joule preamp (love it) and a Surround Sound Acurus preamp. After an extended (over two days) period of time on, it will start feed a distorted signal to the speakers. This has occurred with both preamps and different speakers. After the amp has been off an extended period of times the sound is normal.

I am curious before I send the amp off to be fixed by Noble Electronics what you think this could be?


Possibly either a cold solder joint that is affected by heat buildup, or an electrical component that is affected by heat.

Sounds like a bias problem to me. Heat can make the bias drift if the feedback loop (or the component tolerances if zero feedback) isn't quite right. If it drifts enough, you get a distorted signal for sure. I think it is a big problem that should be easy to locate by a knowledgeable tech.

Thanks a lot for the responses. I should ship it off next week and will let your know the answer.