my question to the EE's out there is, does an amp draw the same power regardless of volume level, or does higher volume level draw more power? I'm wondering because it seems to this non-EE (I did high school physics but that's about it) that volume would be regulated by a variable resistor, so with lower volumes resistance would be turned up to limit actual output to the speakers, but this current would be "lost" as heat in the resistance. for higher volumes, the resistance would be turned down to let more current through to the speakers to do "actual work" in driving speakers to higher SPLs. that being the case, the amp would then draw the same amount of current regardless of what volume it's playing back at, and low volumes would mean more current lost as heat. OR:- do amps somehow draw less current at low volumes, which seems to make sense since the amp is doing less work in driving the speakers? if so, how exactly does a volume knob reduce the amount of power drawn? perhaps my earlier simplistic model of variable resistors is only used in simple devices (e.g. portable transistor radios) and sophisticated hifi amps and receivers use some sort of logic circuits? oh well. could someone with the requisite electrical/ electronics knowledge humour me please with an answer?