Let me dispel a few myths and some bits of misinformation:
1. "Surge protection" (so called), as provided by all of these 'power grooming' devices is no better than what already comes built into your components, if they were constructed in the last 10 years, and some even earlier. That is to say, they add nothing to what you already have in the component itself. AND it's not enough to really protect your equipment from a real HIT, like a lightening strike -- to protect yourself from that, you need to unplug your system from the wall -- period. The only exception to this strategy is using an isolation transformer which PHYSICALLY as well as elecrically separates your stuff from the power grid.
2. A 'battery back-up', part of a class of devices better known as an UPS (uninterruptable power supply) can be added to any system. They are commonly for computers to save critical data, or finish critical transmissions, before allowing the computer to shut down if power is not restored soon. But computers are relatively low power consumers compared to even a 100W/channel SS amp. You won't be listening to your music very long if there's any kind of serious power outage.
3. Every regenerator product I know of has voltage support (voltage regulation for over/under line voltage) So does a (much cheaper) device called a Variac. If you have a tube amp that need accurate line voltage to maintain accurate tube bias, but essentially no other big utility company problems, one of these along with a big isolation transformer (for REAL surge protection) would be just the ticket.
4. Regeneration. OK, we're not talking about motor-generators which use gas or electric motors to drive a generator and make fresh power. And, except for the ExactPower (which I'll get to shortly) ALL REgenerators use the same generic method. They take ALL the AC power from the wall, turn it into direct current (DC) and then turn ALL that DC into fresh AC. It works! BUT it's terribly inefficient; which BTW is why all the high-capacity regenerators (except the EP) have to have cooling fans and add significantly to your electric bill. I call this the 'baby out with the bathwater' method;-)
4. First of all, there's really no point in making 100% "new power" because the WORST wall power is only about 20% out of spec. So why not leave alone the 80% of it that's good and just "fix" the rest? That's what the patented ExactPower circuitry does. Middle Atlantic Products purchased the company for that patent -- which they are now using to manufacture full building regeneration systems (which is where the profits are biggest -- not audio ;-) It's a slick solution to an old problem now made possible using computer matching algorithms and Class D amps (perfect for 50/60Hz AC) to turn a sow's ear into a silk purse! OK, it's not exactly a RE-generator by the original definition, but in my view it's better than anything out there.
I had to laugh when I was reading the APS comparitor matrix which suggests that there are a couple of things the ExactPower unit doesn't do that tha APS and PS Audio units do. And it's true! The ExactPower unit DOESN'T do those things. Why? Because it doesn't have to ;-) It's already replaced all the places in the incoming waveform that were noisy or out of spec!
