Two questions if I may.
My amp is a U.S. made Son of Ampzilla, powered for the U.K. but with a U.S. style plug on a captured power cable. I live in the U.K…
Out of the wall, and out of a Shunyata Hydra, the amp hummed immediately on turning on, this would then settle and disappear, but then sometimes, but not always, return for no obvious reason and it could be quite loud.
When I powered the amp via a power regenerator I got a lower but steady hum which seemed to recede a bit in time but was always there.
Powered via the P10 I also get a similar result as the other power generator, if a little bit quieter.
The hum is at 150Hz (shows up on a speaker frequency response measurement).
Voltage Out in the P10 was set at 240 volts. The U.K., in common with the rest of the EU, is now supposed to be 230 volts. My Voltage In seems to vary between 232 and 236 volts, THD Out always 0.1%. The manuals of all my gear, where mentioned, say 230 volts.
Should I set the Voltage Out to 230 volts, or perhaps 234 volts (average of Voltage In) to reduce P10 workload? Can this improve sound? Or amp humming for that matter?