The hum very likely is a ground loop. Do you have cable tv or a satellite receiver hooked up? Try disconnecting them to see if the hum goes away.

2xM80 VP180 2xQS8 2xM3 HSU STF3 LG 60PS11 Denon 3808 ATI 1506 LCR 2xATI 1502 Oppo BDP-83