I have had the amp/receiver for about a month, have noticed it seems to have started humming through the speakers. Even when the amp is muted there is quite a loud humm. I assumed it was due to bad earth, or connected equipment. I have pulled the amp out, with no inputs connected, 1 speaker wired on the floor into the amp, and still i get humm. I have now tried putting it on a UPS to ensure clean input, and still humm. I guess its faulty - any other suggestions Dean.