03-02-12: StringreenWhile I would not completely rule out the possibility of adverse effects on audio quality, if there were any such effects it would not be because of power depletion. For typical speaker efficiencies the hum levels we are discussing probably correspond to less than a thousandth of a watt.
The hum that the above poster is talking about comes from the Grado cartridge. They don't do well with some arms. Even if the hum is inaudible when playing music, it depletes the amp from valuable power and lessons the quality of the audio.
Regards,
-- Al