By the "same phase," you mean that the dedicated audio circuit breakers should be installed on the same side of the breaker panel, using the same leg of 220V feed, right? That will make all the DC ripple coming out of audio power supplies more harmonious when passing signal from one component to another. Great idea. Shane suggested that to me recently, but until now I did not understand.
What if you install a dedicated power panel near the system. That would use a 220 line to the new panel, and then you would have 2 legs of different phase for the breakers. How do you decide how to apportion those?
Preaching to the choir here, I know, but just to encourage Ken to go for it: I moved my system upstairs a few months ago, and plugged into a couple of shared 15A circuits. The added noise and reduced tone quality was a real eye opener for me, and I have excellent underground power from a huge ground level transformer. What happens in the house wiring is critical for high end audio. On dedicated 20A line, overall sound is much superior. Hubbell outlet and Black Sands cables help too.
Picking up on the grounding thing, ya gotta have only one earth rod, but a separate audio panel would be grounded directly to the one house service rod anyway, giving a nice quiet ground, in theory. Two separate rods seems tempting for even quieter ground, but it is illegal, because a lightning strike with two unbonded earth rods makes a big house fire. The slightest voltage potential (different resistance to earth) between the two rods causes hundreds of amps to flow through equipment and house wire rated for 15 or 20, or even 100amps between panels, it will all explode with a lightningstrike leaving molten metal sprayed inside the wooden walls. No insurance payoff either. Get a pro, Bolton is great around here, I've used them many times.
Rich