220 or 110 volts for amplifiers

[stalag2005]

You can wire a home for 220/240 throughout the home, but that presumes that you find all 220V devices for use in the home. In the USA that would be difficult at best. The 110V was picked as a safety factor by Edison and that choice stuck us with 110V.

 

[Speedskater]

Not really, as it is predictable. The thermal imaging over the power transformer would be down by about four fold over the primary windings. The primary windings would generate four times the heat at 120 volts as compared to 240 volts. That is simple math and 100% predictable, due to I squared R heat losses.

More audio amp's have power transformers with two 120V winding's. Connected in parallel for 120V and in series for 240V. So each winding will have the same current & voltage in both cases.

 

[TLS Guy]

More audio amp's have power transformers with two 120V winding's. Connected in parallel for 120V and in series for 240V. So each winding will have the same current & voltage in both cases.

Well that is obviously not true. If the voltage is halved then the current has to double. If that were not so, the receiver would only get half power. So the heating has to be four times higher in the primary on a 120 volt system, compared to 240 volts.

Series connection in a transformer is not like a resistance. Only the heat generated by the DC resistance. A transformer is two coupled inductors. The coupling is magnetic not electrical. So the turns ration is different for the 120 and 240 connections. So the 120 set up sees half the impedance of the 240 volt set up. Remember impedance is not the same as DC resistance at all and different rules apply.

 

[Speedskater]

In the 240V case you sum the voltages of the two winding's.
In the 120V case you sum the currents of the two winding's.