Using autotransformers

It has been suggested to me that the best way to avoid incoming voltage irregularities from the street to my Krell mono blocks is to add an autotransformer to each amp's dedicated 20 amp line.

It was also not recommended that I use ordinary voltage regulators because they reduce sound quality.

Have any of you had experience with autotransformers in your system? If so I would like to hear your feedback on this.
Ferro-resonant transformers don't work so well for audio. They make a lot of physical noise and electronic noise too.
The AVS looks interesting. I can contact them for more info but do you know, of hand, if the AVS would handle the load for 2 Krell Monos or would you have to buy an AVS for each amp?
Hard to say. Monster's website seems pretty bad, and does not say how much current the device can handle. You will have to call a dealer or such and find out.