Cavedog. I don't know about the US but in the EU all electronic equipment has to meet very stringent standards for EMI ingress and egress. This can be a protracted and expensive business for new designs.

I can assure you that "our" amplifiers met the standards. I never in 3 years had a complaint of RFI trouble, not even with amplifiers with IC front ends! I did have a guy with a problem but it turned out he lived only a few 100 yards from some hush-hush naval transmitting ***t. Nothing was going to keep THAT out!

It is not possible to reverse a mains plug in UK unless you chop off the moulded one and fit another, wrongly.