I have a Bryston 4B Cubed amp plugged in to a P20. With no music is playing I hear a low level hum coming from my Bryston amp after powering on. It’s not loud enough to hear from my listening position but it’s definitely there when I am up close. When I plug the amp directly in to the wall the hum goes away. The wall outlet is the same one my P20 is plugged in to. No other components have any issue being plugged in to the P20. It also doesn’t have any bearing on the sound quality of my system.
I tried the clean function on the P20 which I thought helped a bit but the hum comes back almost immediately or very quickly. It’s also there with regular and multi wave. Multi wave sounds really nice on my system so I want to keep the Bryston plugged in to the P20.
Any thoughts on what may be causing this? Other troubleshooting ideas?