I have a couple month old Fender Blues Deluxe. When I play with the amp on the carpeted floor, there is a ringing sound similiar to a metallic rattling. When I pick the amp up and put it on a stand the ringing seems to dissapear or at least become inaudible. Does anyone know what this is?
Might be something in the room, or it could be the reverb pan or the metal chassis. When you take the amp off the floor the sympathetic bass frequencies that create punch and subharmonics are dampened, so less likely to rattle.
Its probably something in the room, try your amp in a different room.