Which sounds best, 120 volts, or 240 volts?

Folkfreak is right about what I meant - Watts = Volts X Amps.

folkfreak2

@cleeds I presumed @joeylawn36111 meant the case of a component designed for dual voltage operation (or switchable between the two) in which case for a given power draw the current will halve as the voltage doubles.

Sorry, you are mistaken. At a given power draw, the amperage will halve as the voltage doubles. The current remains the same.

Amperage and current are the same thing. Ohm's law is current over voltage times resistance. So the unit's needs have not changed, (the unit being the resistance) only the voltage is higher, so the amperage, or current if you want to call it, is lower. The 50 or 60Hz is the frequency of the alternating current, doesn't really come into the ohms law equation. Although it does have an effect on impedance. Which is what they call AC resistance. Most pieces of stereo have a multi tap transformer inside. Made to have different windings for several different possible voltages around the world. The 110 tap may be attached right in the middle of the 220 windings, so the number of coils have been cut in half. Or, the other way round? So the transformer is actually acting as a whole new device, a different ratio of windings to produce the same outcome for the device to consume. Switching from one to the other could in fact add 100 feet of coiled wire to the Input! Between the wall and the actual circuit. These are big differences! A change in impedance, adding or subtracting a very long length of wire in the transformer, one would think the piece of gear would definitely sound different?

Amps, current. Talking about stuff you don't understand.

Would not an amplifier sold in both the US and UK have exactly the same circuit boards inside and differ only in transformer / rectifier? And does this not make the question moot?