Al's last point is a good one and begs more backstory: I've been eating components *and* speakers during all of this, at a rate that doesn't otherwise make sense. The whole trouble started most of three years ago with some Parasound gear that would develop a "whooshing" sound in one channel, almost like when one of your ears is full of water, that could be dissipated by wiggling the IC between the pre- and power amp.
Is that the exact-same problem I'm having now? No, of course not -- but the person from AA with whom I spoke on the phone suggested that, if the mains had an insufficient earth ground, and/or significant DC offset, these problems would compromise the components' ability to deal with the cr*p that was being handed to them from elsewhere in the signal path, like RF or digital noise, and could even lead to damage.
I've eaten a left-channel tweeter in one expensive pair of speakers, a left-channel midrange in another (using different amplification), and sent three different amp/preamp combos away for service, with varying conclusions coming back from the manufacturers. As often as not, even noticeably audible problems with the electronics have not been repeatable on the bench -- which would further suggest something having to do with power, no?
Is that the exact-same problem I'm having now? No, of course not -- but the person from AA with whom I spoke on the phone suggested that, if the mains had an insufficient earth ground, and/or significant DC offset, these problems would compromise the components' ability to deal with the cr*p that was being handed to them from elsewhere in the signal path, like RF or digital noise, and could even lead to damage.
I've eaten a left-channel tweeter in one expensive pair of speakers, a left-channel midrange in another (using different amplification), and sent three different amp/preamp combos away for service, with varying conclusions coming back from the manufacturers. As often as not, even noticeably audible problems with the electronics have not been repeatable on the bench -- which would further suggest something having to do with power, no?