I recently bought the 950/7100 for my 5.1 set up and am very happy with it. With a bit of time on my hands this weekend I thought I'd try biamping the left and right mains with my two spare 7100 channels to see if it made any difference. I do think it's taken a little of the brightness from the tweeters on my B&w CDM 7NTs so I'm happy with the result, but something interesting is happening.

When I shut down the 950/7100 I'm now getting a high-to-low frequency whine coming out of my main speakers that fades to silence after a few seconds. It's not loud, and I doubt it's doing any harm (I think it may simply be a capacitor in the 7100 discharging) but I never had this before I did the biamping.

Any ideas what might be happening?