Geoff,
A voltage regulator is a good idea, but usually these voltage regulators have a higher output impedence (does not supply current very well). So that is the problem. But if you can put these behind a balanced power conditioner or an isolation transformer (as suggested by Jay S), it will sound good (as the current demands on the voltage regulator is reduced).
I just experimented by connecting my Blue Circle Music Ring to my Monster Power 2500. Normally, connecting an amp to the Monster would reduce the dynamics. But now I have the Music Ring in between, I dont seem to notice any reduction in dynamics. Above that, I have better microdynamics and ability to hear into low level details much better. For eg, the very low level delays added to the vocals (echos) are now easily discernible.
This multiple stage approach is also advocated by ExactPower. They have a device which produces a clean sine wave. This should be used in conjunction with the balanced power conditioner they make. I have seen people using just the sine wave regenerator alone not fully satisfied with it.