I am presently using an Exactpower EP-15. It is very efficient because it regenerates only a fairly small percentage of the AC waveform. It provides a very solid and stable 120v +/- 1% @ 60hz. It uses very little power in doing so. It makes my 100pc integrated amp sound like it's on "stereoids". Digital clock circuits love it.
I use an outboard filtering device for digital filtering and isolation amongst the components. That device is directly plugged into an outlet on the EP. The amp is plugged directly into the EP, devoid of filtering. Exactpower also builds a balanced power unit.
I will admit that the EP did in fact have a slightly undesirable sonic signature after about 200 hours of break-in. Although, it was fairly easily corrected by replacing the EPs power cord with a higher quality cord, and applying some vibration dampening material to the inside of the EPs aluminum cover. The unit runs stone cold no matter how hard it is being driven.
For me, music took on a very convincingly real sound (after break-in and the minor mods). The amp seems to remain "at ease" when reproducing highly dynamic passages at fairly high volume levels. The noise floor is lowered to the point that the most subtle details are revealed, and the background is absolutely black. The EPs sonic signature now seems to be nonexistant.
If you are just starting to investigate this technology. Good Luck! The amount of manufacturers and products available is bewildering. Although, you are absolutely heading in the right direction.
Happy listening....
