Just to be clear:
This is not 60 Hz or some 60 Hz harmonic leaking into the sound system, but instead an increase in _distortion_ in the sound system when the lighting is at reduced power?
If the input to the sound system is totally silent, do you hear the distortion, or do you only hear distortion when there is some input (eg. someone speaking into the microphone)?
Is the distortion or noise _source_ dependant? Does it matter if you are using a microphone or a tape recorder as the input source?
-Jon
