A few years back I had trouble with a "Metallic Buzzing" noise coming from an old Peavey rig I bought to use for practice at home, tried alot of things and still had the annoying buzz. I decided to try moving it to another part of the room and lo and behold, the buzzing stopped. It turned out that the amp was making one of the return register vents on the wall vibrate and buzz. I swore it was coming from the amp.
