ditusa
any transformers on the main AC power lines feeding your audio equipment will degrade sound quality. That is the reason why I run all my audio gear on 240 volts ...Your power went through multiple transformers as part of the electric grid's distribution system before it reached the transformer in your neighborhood. There's no way to be rid of them. Your audio components also contain transformers.
BTW, 240 volts, is more efficient then 120 volts, 240 volts, is half the amps as 120 volts, 240 volts is quasi balanced power.No, the two have the same efficiency - the current is the same at either voltage.