Axiom Home Page Forums General Discussion Technical Questions A person I work with is having this problem???

I had said it sounded like the vacumm was causing a back feed into the receiver. I am curious as to whether or not his house wiring is newer or older? If newer, the receptacles should be polarized and my theory is not valid but if they are not polarized the plugs could be wired inconsistantly and pulses etc from electrical items could be coming through any surge protection on the wrong side of the plug(neutral) which might not have internal protection on the amp.