tincanear
Headphoneus Supremus
Thanks for these thoughts. I have installed an APC voltage regulator which only show high/low and an OK light, so it doesn't have the granularity needed to detect transients.
I'm working through all the options we have identified: your list adds a few, thanks!
what model is the APC? some can only adjust +- 10% with a tapped transformer using relay switching, and might create more noise, esp during the tap switching. 4 percent high line voltage itself shouldn't be a problem for properly designed audio gear.