So in US< in essence, isn't "clean" AC power predominately 60hz, and any variations from this "noise"?Yes, except that I would say "noise or distortion."
Can an oscilloscope make this distinction?Yes, mostly. It can certainly distinguish between 60 Hz and broadband noise (within the bandwidth limitations and amplitude resolution capabilities of the particular scope, which for a decent quality scope I suspect would be good enough for this kind of purpose). Relatively large amounts of distortion could probably also be quantitatively characterized in a reasonable manner with a scope. It might not be possible, though, to assess relatively small amounts of distortion (that might still be great enough to have audible consequences in some systems) without a spectrum analyzer or other comparable instrument.
If so I would expect it to be useful to help determine "clean" power.My reference to usefulness was not with respect to determining the degree to which the power is "clean," on an overall basis. It was with respect to usefulness in resolving sonic issues, and/or making purchase decisions about power conditioners and regenerators, in response to your initial question:
The effect the AC power, signal noise or otherwise, has on sound case by case or not is another story, out of scope of what I am trying to understandl which is merely how to distinguish noise from clean signal with AC power.
03-19-14: MapmanBest,
Beyond the multimeter, which is a logical first step, is there an affordable gadget out there that can be used to actually measure AC line noise? That would take a lot of guesswork out of the equation when attempting to determine value of adding conditioners, regenerators, etc.
I'm thinking an oscilloscope type device could certainly be used but something more affordable and easier for a lay-person to use and get a clear determination of line noise frequencies and levels just for this purpose?
-- Al