In my experience, power line conditions have almost no influence on actual, static _hiss_ generated by a particular unit. This type of noise is a function of the noise generated by the various opamps and other audio and video stages within a component. Pops, buzzes etc. are what are manifested by most junk on the power line. In cases where 'hiss' can be attributed to the AC line, it always turns out to be RF interferrence which in most cases goes right through the power supply of most equipment through capacitive coupling in the power transformer. A power line filter such as the Monster, or "Isobar" by TrippLite will filter this out. These filters will also isolate components to filter out any inter-device coupling of high frequency noise. The level of RF interferrence has to be relatively high, such as when you live near a transmitter tower, or someone with a CB transmitter, for it to be heard through most equipment . Occasionally, such interferrence can be generated by appliances which use the AC line to transmit data, such as the X-10 modules, and units which transmit audio/video through the AC line. Also, some light dimmers can generate noise which contaminates the AC power, and is heard as a buzz through the system. The solution for this is to use autotransformer type light dimmers, as most AC line filters cannot filter this noise out.


[This message has been edited by soundhound (edited December 20, 2002).]