One other option. Your receiver or amp may be an ungrounded design. I'd guess it might be the receiver since I doubt Bryston would design an ungrounded amplifier. For example, I understand from John Tucker of Exemplar Audio that the Denon 2900 is an ungrounded design. Who'da thunk it?
You can try an AC cheater plug on the Bryston or the receiver to lift the ground. Try it on one then the other. It may do the trick.
You can try an AC cheater plug on the Bryston or the receiver to lift the ground. Try it on one then the other. It may do the trick.

