I just returned from vacation and switched on my 2 channel amp (NAD C-272) before switching the pre on (B&K Ref 20) (sleep mode). I got a very loud screatching, static constant sound. I pulled the 2 channel outputs from the pre and still got the same sound. When I pulled the inputs to the amp, the noise stopped. It also occurred on the Zone 2 outputs on the pre.
I checked all connections and plugs, etc. Turned the main power off and on. Now, the unit does not make sound unless the interconnects are plugged into the AMP and the Pre...this is a very loud hum even with the volume on the pre turned way down.
No one touched the equipment while I was away. Help please.
[it does appear that there was a power outage while I was again as some clocks needed to be reset and my external drive on the computer was off....I have a very cheap surge protector on the amp...and did try plugging it straight into the wall with no change]