I’m curious, how many people are aware of these sounds. I have designed, etched, and built my own switching power supplies along with winding my own transformers. I am aware of the source of the noise. So, does anyone else hear these high frequency sounds regularly?
You’re correct that it’s not the high pitch sound from the old days. Now it’s more like a,low pitch hum. But it’s still there.
Interesting! I haven’t had this happen with any speaker or amp in a good decade. I wonder what it is!