Platypus9 wrote:I tried the amp from an outlet on the first floor, and the RFI was barely audible. I then ran a heavy-gauge extension cord to the 2nd floor, from the same outlet on the first floor. Result: intense RFI.
I think both of those tests show very clearly that the amp is heavily reliant on extremely good earthing to control RF interference. So in situations where there is little RFI around, or where it has a really solid earth, it will probably perform perfectly.
However, whether its susceptibility to RFI is a fault on this particular unit, or a design flaw I can't say. The attentions of a good tech should sort it out relatively easily though, I'd have thought.