Which sounds best, 120 volts, or 240 volts?

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?

The point was, if a power cord can make a difference in sound, would not operating on a different frequency, transformer, etc. make a huge difference in sound? And I'm afraid I do know what I'm talking about, I've got a college degree in electronics and computer sciences. Current is measured in amps, voltage measured in volts, and resistance measured in ohms. Power is measured in watts, or amps times volts. Alternating current goes from positive to negative and back is one cycle, if it made one cycle in one second, that would be one hertz. So 50Hz changes polarity 50 times a second, and 60 Hz changes polarity 60 times a second. But none of that is the point of the post, just the fact that these differences are HUGE compared to swapping a power cord, they should be readily audible. 
That, is the only point I'm trying to make.