NAD 7100 preamp/tuner/amp Suddenly the balance changes, or perhaps one channel gets lower. Sometimes some popply or scratchy noise but mostly the image moves left or right... occasionally, then it settles down for a while, then again. I assume some volume control circuit is messing up? Any fix? Any suggestions?
Hugh, does this happen only with the tuner? Do you have another source to try, a cdp perhaps? Have you tried another input to the preamp, or switched interconnects around?
Have you serviced or replaced speaker leads in recent memory?
It happens with tape or cd input. I suspect the preamp section. Speaker leads are old but I wiggled them to no effect. It seems more temperature, corrosion, or capacitors in some kind of volume/balance circuit. Tapping the circuit board and wiggling gives no output noises. Switched interconnects to no effect. The manual mentions "feedback controlled volume control" or some such. Perhaps this circuit is failing and muting the output. Know anything about this feature?