Tweakers' Asylum: REVIEW: Equi=Tech ET2RQM Power Conditioner/Surge Protector by Bruce from DC

Model:	ET2RQM
Category:	Power Conditioner/Surge Protector
Suggested Retail Price:	$2,100.00
Description:	balanced power isolation transformer and surge protector
Manufacturer URL:	Equi=Tech
Manufacturer URL:	Equi=Tech

Review by Bruce from DC ( B ) on October 30, 2002 at 11:18:36
IP Address: 207.91.86.5

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What it is.
Unlike a lot of power products, which seem to be designed in conjunction with creative ad copy writers, this is a straightforward device with no magic dust or apparent reliance on exotic physics. It is simply a very big isolation transformer that converts 120 VAC house power into two opposite phase 60 VAC legs with a derived ground between them. Thus, the potential difference between the two legs is always 120 Volts; but, unlike with conventional US house power, the potential difference between each leg and ground is only 60 volts. (US house power has one "neutral" leg, with zero potential difference between ground and one "hot" leg that has 120 volt potential difference to ground.) Simlar products are made by Furman Sound, Cinepro, Balanced Power Technologies, Blue Circle Audio and (in kit) Transcendent Sound. Rather than try to pretend to be an electrical engineer, I will refer you to these companies' web sites for their various explanations of the benefits of balanced power. Clearly, the presence of a big inductor on the line reduces incoming RF, lowers the output impedence of the power source and blocks DC components in the power. This device is not a regenerator like the PS Audio Powerplants; so I doubt that it corrects waveform distortion. I think the big benefit is the "derived ground" which greatly reduces the possibility of ground loop currents. This Model has the "Q" transformer, which is claimed to avoid the power inrush surge that often makes other models trip house circuit breakers at start up. It also has a digital readout voltage meter that can be switched to read either input or output voltage. The transformer provides a slight voltage boost. Incoming 127 volts comes out as 132 volts. There are front panel switches to control the transformer primary and secondary. As claimed, the unit does not dim the lights at startup, leave alone trip the breaker. This model is rated at 20 amps and uses a special 20 amp plug on its detachable power cord, which requires a special 20 amp "heavy-duty" outlet to be installed. Since I am nowhere near close to needing all 20 amps, I have it connected to a standard 15-amp house circuit.

What's it sound like? Since the Equitech produces a derived ground, I did not feel it would be meaningful to connect some components to it and leave other components connected directly to the house power. It seemed to me that doing that would very likely produce ground loops, and would not be a fair comparison. Therefore, the comparison is on a system basis, in place of the Monster HTS 2000 I used before.
Digital playback
I started out playing CDs, where this device makes a significant improvement. The first thing that I noticed was that I wanted to play the music louder, which suggests to me that this cleans up various subtle forms of digital harshness. (My theory is that the limiting factor on loudness of playback is when some form of distortion in the system becomes annoying -- at some level below obvious audibility.) The weakness of digital -- reproduction of transients, especially high-frequency transients -- seemed to be greatly improved. Playback of digital "challenges" like cymbals on a drum kit, brass wind instruments and even piano, was less harsh. Trumpets were even sweet, and the sound of cymbals was revealed to be more complex.

The totality of the musical presentation was more "immediate" in the sense that front-to-back dimensional relationships were rendered in considerably more detail. There might have been a slight improvement in the impact of bass transients, but I can't be sure. Playback of ensembles was rendered more as a collection of individuated instruments and less of a congealed mass.

Analog

One thing this product did not seem to do was serve as a noise killer. I live in a very high RFI environment, which affects lots of electronic devices around the house, including telephones, keyboards and, of course, stereo. There remains some buzz/hum that comes predominantly from the left channel of my system with the phonostage connected, even though the phono inputs are terminated by shorting plugs. Similarly, the subwoofer still hums slightly, even with nothing connected to it. I have not finished troubleshooting the phono problem; but it may be some incompatibilty between the integrated and the phonostage, perhaps relating to the way the integrated handles its balanced input.

Vinyl playback was improved, but not as dramatically as digital. Once I returned to my high output moving magnet cartridge (so the gain used made the hum inaudible at loud listening levels unless you put your ear very close to the speaker), vinyl playback was very, very good. The sense of "cleaning up" high frequency transients was not present; they were clean to start with. What was slightly better was the individuation of instruments and voices in an ensemble, especially in a live recording. Bass was really exemplary in terms of both accuracy and weight, which is a characteristic of this cartridge and phonostage.

Overall, this product did an excellent job of cleaning up digital and making the whole system seem a little more powerful, in terms of preserving macrodynamics at loud listening levels. In addition, it made subtle improvements in already excellent analog playback.

Product Weakness: Very heavy (50 lbs.) At some level, an expensive, but effective tweak. Not a universal cure for all noise problems.
Product Strengths: Improves digital substantially; subtle improvement in analog. Seems to make system overall more "powerful" sounding.

Associated Equipment for this Review:
Amplifier:	Krell KAV-300i (integrated)
Preamplifier (or None if Integrated):	BAT VK-P5 (phono)
Sources (CDP/Turntable):	Ultech UCD-100 CDP; VPI HW-19 Mk3/ JMW 10/ Clearaudio Aurum Beta S
Speakers:	Joseph RM-7si signatures; Mirage BPS-150 sub
Cables/Interconnects:	Goertz Triode quartz; micropurl AG; DH Labs speaker wire
Music Used (Genre/Selections):	jazz band; classical piano/vocal recital; jazz/pop combo vocals
Room Size (LxWxH):	25 x 12 x 11
Room Comments/Treatments:	lots of books in shelves, rug, drapes
Time Period/Length of Audition:	week
Other (Power Conditioner etc.):	unit under review
Type of Audition/Review:	Product Owner

Product Weakness:	Very heavy (50 lbs.) At some level, an expensive, but effective tweak. Not a universal cure for all noise problems.
Product Strengths:	Improves digital substantially; subtle improvement in analog. Seems to make system overall more "powerful" sounding.