HIGH Quality Electric Service Panel

I like Siemens for two reasons: (1) it's German, and (2) their high duty breakers and their regular breakers have the same part number. That means, IMO, that their regular breakers are made to high duty standards (i.e. 2000 on-off cycles).

My audio sub-panel is Siemens, and I also use their circuit breakers for on-off switches, and haven't had a failure, though it's only been 4 years.

I agree with cleeds: ground the panel with your house ground, or you may end up with a ground loop. Siemens, by the way, has a surge suppressor option.

Thing is that toroids like to growl while they work. Not what you want in your music room.

Balanced power can be a good thing, unless the equipment manufacturer connected the neutral leg of AC to ground. With normal utility power that's not a problem, but with balanced?

I would say more recently than that Jea, but I may be wrong. In any case, there are too many refurbished classics floating about to give a blanket assurance. Beware the two-prong plug!