For about a year now I've either had an intermittent problem or an intermittent psychosis, and it's turning out to be really difficult to tell which one it is:
The sound from my system is often dry, reedy, really unpleasant -- even my girlfriend can hear it -- and the problem seems to be of an electrical nature. There's a sort of a buzzing noise through the upper midrange and low treble -- sort of the audio equivalent of those little trickles we used to see on the television when dad was running the electric carving knife in the next room.
If I experiment with different connections (interconnects, power cables, etc.) I can sometimes -- but not always -- make the sound come booming in, perfect, so there's no possibility at this point that what I'm hearing is speaker damage. The trouble is that the bad sound doesn't always go away when I do this little disconnection routine (I've tried every configuration, scientifically), and it always comes back, no matter what I've swapped.
One other symptom that might be interesting: when I get really lazy in my detective work and start connecting speakers to an already powered-up amp and preamp, I can hear a whisper of cloudy-sounding static, almost like the sound your ear would make if it was full of water. I know a person should never hook speakers to powered-up equipment, but in the past when I've done this incredibly stupid thing I haven't heard any such crackle.
It's not the source because it happens on different sources, and it's not any of the cables because I've switched them all out at least once. It's not RF pollution because I've treated the whole system extensively and, besides, it's in the wrong frequency band.
The mains in my house are NOT grounded, so at this point I'm thinking that it's a buildup of fault energy in the amp or preamp, but why would that affect the sound intermittently, and why only in this very peculiar, difficult-to-pin-down sort of way? Could a "bad cap" be the culprit? Any ideas are appreciated. I don't *think* I'm delusional, because non-audiophile friends can hear the difference, but on the other hand this problem has spanned several configurations of gear.