General Asylum: REVIEW: ExactPower EP 1000 Power Conditioner/Surge Protector by Pete Watt

Model:	EP 1000
Category:	Power Conditioner/Surge Protector
Suggested Retail Price:	$1299 (audiogon price $950)
Description:	AC Purifier and Voltage Regulator
Manufacturer URL:	ExactPower
Manufacturer URL:	ExactPower

Review by Pete Watt ( A ) on September 21, 2002 at 13:10:27
IP Address: 198.81.17.174

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for the EP 1000

I recently completed a series of listening tests in which I auditioned three products with differing power conditioning technologies. My objective was to evaluate products with enough capacity to support all of my major systems components, specifically a Spectron Class D digital amp (300wpc), Conrad Johnson PV-12 tube preamp, Monolithic Sound P3 power supply (for my Perpetual Technologies P-1A DSP and P-3A DAC), and Cal Audio Delta CD transport. The three products I auditioned were the ExactPower 1000 AC Purifier/Voltage Regulator, the Shape Electronics Ferroresonant Transformer and the Balanced Power Technologies Isolation Transformer.
Power Conditioning elements already installed:
To level set, my base case going into these tests included, from a power conditioning point of view, the following: 20 amp dedicated circuit in my listening room, FIM audio grade wall outlets, high-end Harmonic Technology Fantasy power cords, a Furutech power distributor with some noise filtering, and various hardware mods to reduce the noise floor in some of my key system components (e.g. CJ PV-12).
Also, before beginning this test, I had auditioned one highly regarded power conditioner featuring a high grade filter - the PS Audio high current Ultimate Outlet - with mixed results. When I tested the UO in support of my Spectron power amp, the sound became more closed-in and far less revealing. Alternately, when I tested the UO in support of my digital sources their was some marginal improvement in base extension, clarity and detail, but not as much as I had hoped for. Frankly, my experience with filters generally and the UO in particular has been to steer me away from filter-based solutions and toward other technologies that have the potential of providing high grade power conditioning for my entire system, including my 300wpc amp (which drives a pair of power hungry B & W Nautilus 802 speakers).
Finally, I decided to exclude from the new series of tests the PS Audio power regenerators, since the only unit that had the capacity to support my amp - the PS Audio P1200 - requires a 220V circuit and is very expensive to acquire and to run.
Listening Tests: ExactPower 1000
For those of you not familiar with this product, the EP1000 is termed an AC purifier and voltage regulator (not a regenerator) and its technology is optimized to do the following: 1) Maintain a rock solid constant 120V AC output within one percent at very low impedance, 2) correct in real time poor or damaged sine waves to create the perfect waveform, and 3) in the process remove all harmonic distortion. The EP1000 is a de-rated version of the older EP2000, substituting 7.5 amps and 1000W for the previous 15 amps and 2000W at a much more attractive price. It should be noted that both the EP1000 and 2000 have now been discontinued in favor of the newly announced EP15A, which offers 1800W at 15amps with some minor improvements and at different price point ($1799). I choose to proceed with my test utilizing a used EP1000, since 1000 watts was more than adequate for my system.
The first thing I did upon installing the EP1000 was to plug in the Spectron amp. The result was phenominal -- better base extension, much more natural midrange, exceptionally better soundstage (more dimensional), and greatly improved clarity and delineation. Next, I switched over the CJ preamp and there was additional improvement. Finally, when I added my CD transport and Monolithic power supply driving my Perpetual DSP and DAC, things sounded better, although not at the same magnitude as with the Spectron and the CJ. Plugging the Furutech power distributor/filter in between the digital gear and the EP did nothing plus or minus, and accordingly the Furutech became redundant.
Listening Tests: Shape Ferroresonant Transformer
Although based on a different transformer technology, the Shape FR unit is designed to accomplish essentially the same objectives as the ExactPower product, i.e. constant regulated AC power output, corrected sine wave, etc.
When I connected the Spectron amp to the Shape transformer, there was a noticeable improve in sound, but nothing close to what I experienced with the EP. That and the fact that the Shape FR unit is acoustically very noisy led me to drop it from further consideration.
Listening Tests: Balanced Power Technologies Isolation Transformer
The BPT technology is very different from the EP AC purification/regulation and from the technologies commonly used in power conditioners based on filters. BPT features balanced power and component isolation techniques to lower the overall noise floor in the system. For my test I left my Spectron amp plugged into the EP1000, but put all the other components (preamp and digital sources) into the BP-Junior (BP's most econimical unit capable of handling 2.5 amps and 300 watts). Plugged directly into the wall, the BP definitely was an improvement over the Furutech power distributor/filter, especially with regard to base extension and overall definition and clarity. Next, I unplugged the BP from the wall and plugged it directly into the EP. Things improved signicicantly. But then, finally, when I removed the BP entirely and left the CJ and digital sources on the EP, nothing change, up or down.
Conclusions:
1) Rock solid clean regulated power is clearly the big winner, especially when it comes to the power amp and preamp, but also incrementally to the digital sources. The magnitude of the improvement I experienced was dramatic. In addition to the elements I cited before, I heard for the first time in my system absolute dead black quiet!
2) The broad based system wide benefit delivered by the EP was far superior to all of the narrower noise floor reducing filter technologies I have tried including the Furutech.
3) The BP technology based on balanced power and component isolation was certainly superior to the simple filtering in the Furutech, but was not as good as the ExactPower solution.
4) What surprised me was that, with the BP plugged into the EP, there was no additive benefit from what appears to be complementary technologies. The high quality sound gained from plugging all components into the EP with no apparent need for isolation speaks well for the ExactPower common ground design. And clearly the befefit of balanced power in noise reduction was trumped by the clean regulated current put out by the EP.
Future Tests: Regenerators
As I indicated before, I ruled out power regenerators from my current series of tests due to the prohibitive price involved in supporting all systems components including the Spectron Amp. Now, however, having decided to keep the ExactPower unit permanently in my system, I'm beginning to plan for a future series of tests that will involve at least one power regenerator. In these tests, since the Spectron amp will continue to be plugged directly into the EP, I will have the flexibility of auditioning less expensive power regenerators, handling only my digital sources, or perhaps my digital sources plus the CJ preamp. Although the BP did not provide any additive benefit when used in combo with the EP, its still possible the a regenerator with other functionality (e.g. multi-wave, multi-frequency, power factor correction, etc.) might work very well in combo with the ExactPower unit. More on this later.

Product Weakness: 7.5 amp/1000W spec could be marginal in extremely power hungry environment (e.g. home theater). Would have to step up to EP15A
Product Strengths: Full system-wide power conditioning at a reasonable price; Dramatic (not incremental) improvement in sonics across the board

Associated Equipment for this Review:
Amplifier:	Spectron Digital One (Class D)
Preamplifier (or None if Integrated):	Conrad Johnson PV-12 (tube) w/mod
Sources (CDP/Turntable):	Cal Audio Delta CD transport
Speakers:	B & W Nautilus 802's
Cables/Interconnects:	Audience AU24 analog & bal digital
Music Used (Genre/Selections):	Classical, Jazz, Vocal
Room Size (LxWxH):	22 ft x 20 ft x 15 ft
Room Comments/Treatments:	None
Time Period/Length of Audition:	Six weeks
Other (Power Conditioner etc.):	Harmonic Technology Fantasy pc's
Type of Audition/Review:	Product Owner

Product Weakness:	7.5 amp/1000W spec could be marginal in extremely power hungry environment (e.g. home theater). Would have to step up to EP15A
Product Strengths:	Full system-wide power conditioning at a reasonable price; Dramatic (not incremental) improvement in sonics across the board