Acoustic Revive: RTP-4 Power Conditioner

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All internal connections are crimped since Acoustic Revive feel that soldered connections have a deleterious effect on the sound. (Not unusual: a number of audio manufacturers opt for crimped connections.) Properly done crimps produce more certain and consistent results than soldering. (Back in the dark ages known as the '60s, when a computer consisted of a hundred or more printed circuit boards, socket pins were connected to one another with tightly wrapped, thin wire. Metallic surfaces joined by pressure this way – and this applies to crimps as well – can actually bond on a molecular level and provide an electrically superb joint.) The wire used in the RPT series is manufactured by Furukawa Electrical Industries: PCOCC-A, Pure Copper by Ohno Continuous Casting – Annealed. This wire was designed by Professor Ohno at Chiba Institute of Technology. It is extremely high purity, single-crystal copper, oval shaped (2.2mm x 2.6mm) to eliminate resonance, (The Acoustic Revive site says little more about wire resonance, but if one does a thought experiment comparing a round chime to an oval chime, it seems intuitively obvious that the round tube would sustain longer, since a round tube would have a single resonant frequency, while an oval tube would multiple resonances which would have lower amplitudes and would interfere with and cancel one another.) The same solid core, single crystal wire is used in the matching Power Reference AC cord. Annealing, heating to a specific temperature and cooling at a specific rate in a specific environment, results in (among other things) removing stresses in the crystal lattice and increasing ductility. As I understand it, single crystal structure not only enhances electrical performance (presumably reducing thermal and quantum noise?), but during the annealing process the absence of crystal boundaries on the wire surface provides no access for impurities. (The microphotograph above compares single crystal copper – top – with standard copper – bottom.)


For the companion, hand made Power Reference cord, three such wires are used, each individually wrapped in silk tubing specially woven by Ebisawa Corporation from extra grade silk (silk is available in three grades, extra being the highest purity). This tubing is designed to maintain air space around the copper wire and to prevent build up of static. The three individually silk wrapped wires are then inserted into a flexible pipe of OFC copper. This pipe is constructed along the lines of flexible electrical conduit, made of a formed, continuous spiral of metal. It is treated by immersion in a Teflon solution which seals the surface of the metal preventing corrosion. Copper pipe provides greater shielding against EMI (especially strong fields) than woven strands of fine wire, or thin foil, both commonly used for shielding purposes. The cord isn't very flexible, but once shaped it will retain that shape. Finally, the copper pipe is covered with a woven mesh of very fine polyurethane fibers that has been impregnated with carbon particles. The carbon provides additional shielding from EMI. The cable is terminated with Oyaide plugs, polished to a mirror finish, plated with silver and rhodium, and cryogenically treated.

Materials function. Commercial power, which virtually everyone uses, arrives carrying a lot of noise, a whole spectrum of frequencies, along with 50/60Hz alternating current. Power supplies in audio equipment do not filter out all of this noise; linear power supplies certainly don't, even switch-mode power supplies don't. Nor are they designed to do so. An accessory power filter with a low frequency pass band can filter some of it, but the necessary components of such a filter as traditionally designed – capacitors and inductors and such like – create problems of their own and exact a toll on the sound, often perceived as restricted dynamics. Even if these components were electrically perfect, which they're not, they'd have an audible effect that many audiophiles would find deleterious. Thus the impetus for designing electrically passive power filters.

The RTP series are designed with state-of-the-art electrical connectors. Among their characteristics are highly polished metallic surfaces. This is important. When a power cord with polished, perfectly parallel pin surfaces is inserted in the RTP, there is a large contact area between male and female parts, with few if any gaps that might introduce noise through microscopic arcing. (Interestingly, there is a theoretical limit to how closely the atoms of one surface can be to the other; if they get too close, they fuse.) Now, if these surfaces move relative to each other, if there is any vibration, opposing capacitative and frictional effects occur that can theoretically set up a kinematic oscillation, resulting in variation in conductivity: another potential noise source. The RTP minimizes these phenomena first of all by using connectors that have unusually strong spring action which tightly grips inserted pins, and by polishing them flat. Secondly, selection of materials, careful, high-mass design, accuracy of manufacture, and use of specialized feet, all limit as much as possible the transmission of vibrations. I've already commented on the use of PCOCC-A wire internally, its ovalized shape designed to quash vibrations that have small, but perhaps audible, capacitative and inductive (including self-inductive) effects.

Certainly a unique feature of the RTP is the potting mix lining the bottom of the chassis, containing quartz, lithic tourmaline and green carborundum. There is only the most cursory information about these materials on the Acoustic Revive site. And their attributed behavior is not what I’d call intuitively obvious, nor are some of the claims of the effect of these behaviors on the AC power. But when I mentioned these to a friend who has a lot of experience working with the energetic fields of minerals, she thought the explanations made perfect sense. With the assistance of Joe Cohen, Aki Monobe (of Acoustic Revive), and the internet, I proffer the following information.

Green carborundum, one of numerous forms of silicon carbide, absorbs electromagnetic radiation. Carborundum is a semiconductor (in fact because it is stable under high-temperature and has high-current density, it is useful in applications where silicon would fail). It also has “high coupling” to microwave radiation (radar, cell phones, repeaters, etc), so it will tend to absorb higher frequency electromagnetic radiation (read: noise). Mr Monobe states, “Green carborundum acts like an antenna and converts the EM energy to heat.”

Heat from the green carborundum acts on lithic tourmaline and causes it to generate negative ions. (This principle is also used in the Acoustic Revive RIO-5II negative ion generator.) Negative ions lower or eliminate the buildup of static electricity. One can speculate that the buildup and discharge of static could have physical (capacitative) and electromagnetic effects. That is to say, it could create minute physical movements of the internal wiring (a theory also applied to the audible effect of removing static charge from a CD). The presence of static charge/discharge could also create electromagnetic disturbances that might have an effect, however slight, on the EM field around the wires inside the RTP. But how does the static charge come about? There's science behind the theory.

Static charge can be created through the triboelectric effect. Materials are charged negatively or positively, to greater or lesser degrees, depending on the dissimilar material with which they are in proximity. The further apart materials are in the triboelectric series (, the more readily they create a static charge. This occurs when the adhesion of surfaces results in an exchange of charges, one surface losing electrons, the other gaining. Thus the choice of insulator for a copper conductor can effect the degree of static charge.

Finally there's quartz powder. According to the US Patent Office, the hard science is that if quartz is ground to particles not exceeding 6ҵm (miniscule), and then heated to 200 C or above, it will generate far infrared radiation at room temperatures. This much is certain. Now, Acoustic Revive have told Joe Cohen far infrared facilitates the flow of electricity. How it does this I do not know at this point.

Impressions. I have limited experience with power filtering, yet I have rapidly come to appreciate how big a difference it can make to the quality of sound reproduction. My review of the LessLoss cord goes into some detail about how a power cord can be designed so that high frequency noise is attenuated before it reaches the equipment. The effect of switching from OEM cords to LessLoss cords was very dramatic. Switching from a commercial-grade power strip to the Acoustic Revive RTP-4 (using the Power Reference cord), did not – as I didn't expect it would – have an equally dramatic effect.

Other reviewers did find the effect of the RTP dramatic and there can be many reasons for this disparity: perhaps in installing the RTP they eliminated a dynamically restrictive power filter, or perhaps their power cords were to begin with not as effective as the LessLoss cords I am using, or perhaps they have an audio system capable of greater resolution. Take your pick.

As I understand it, delivering clean power is the primary goal of audiophile AC plugs, sockets, cords and conditioners. While it may be true, for example, that the commercial power delivered in New York City has more spurious noise than power delivered in Seattle, noise riding piggyback on the AC is finite. If a power conditioner theoretically eliminates 90% of that noise, the most that remains to be eliminated by, say, power cords is 10%. Hence even a superb, multi-thousand dollar cord may have relatively little sonic effect. What is consistently said about the RTP, in the relatively sparse English reviews, is that it does a much better job than any power condition the reviewer has heard before.

The standard adjectives flag for me at this point. I found the installation of the RTP-4 produced an immediate but rather subtle improvement. Somewhat greater clarity, instrumental body, richness of overtones. But as time has gone by, I have found myself more and more impressed with the sound. Instruments seem more real. And the qualifier that recurs to me is, there's less. Less of something. It not exactly as if a veil has been lifted. The tonality and dynamics haven't changed exactly. The sound stage and image haven't been appreciably enhanced. There was a great sense of presence before the RTP-4 was installed, so it's not exactly about presence. Yet all of these adjectives might be applied. No, it is rather as if something, something I didn't really notice because I was completely used to hearing it along with the music, has been eliminated. Something that must come riding in on Pacific Gas & Electric's power lines. The music has become more pure, more honest, a more accurate facsimile of a live performance. A small change (or perhaps a number of small changes) wrought by the RTP-4 have, over time, made a big difference in the joy of music listening. I've frequently felt uncertainty judging electronics – does amplifier A really sound better than amplifier B? In what ways better? Is the bass in amplifier B more accurate? Does amplifier A do a better job reproducing the female voice? Does amplifier B have a more convincing soundstage? Does amplifier A project a deeper, more realistic image?

None of these considerations apply with the RTP-4. Top to bottom, one CD after another, vocals, jazz, symphonies, piano sonatas, everything sounds better. After some weeks listening with the RTP-4, my mind open to the possibility of additional descriptive words, one suddenly occurred to me. It's a word I've seen frequently in audiophile literature, one I've looked at somewhat askance, but in this case it seems to apply: microdynamics. It is one of the elusive factors contributing to the uncanny realism of the sound. Fact is, the nature of the change with the RTP-4 is both subtle and pervasive, elusive and obvious at the same time.

I have been delving once again into Beethoven's piano sonatas. Lately it's been Anton Kuerti's impeccable, somewhat restrained performance on Fleurs de Lis (Analekta FL 2 4010). Now, I've yet to be fooled into thinking there's an actual piano in the living room, but often from another room the illusion is uncanny. Go into the living room and the illusion disappears, definitely a recorded piano: acoustics, awkward room dimensions, bass peaks and reverberations (limitations of my loudspeakers) break the spell. But for the first time ever – with the RTP-4 and its umbilical in circuit – the illusion seems to remain in tact even under the far less than ideal acoustics of my living room. Something's changed. There is a palpable piano in the room. (At least with certain CDs.) The experience is, not to put too fine a point on it, wonderful. Well, it's not real enough to make me question my sanity, but it's a damn sight more real than anything I've heard before. The piano strings ring like clarions, the bass seems to reach deeper into my body, and to resonate in my chest, full of power and emotion. Profound. (Now, if only I had a pair of JMLabs Grande Utopia Be's...)

As those of you who have read my recent reviews may remember, I actually do own other jazz recordings besides Clifford Jordan's Live at Ethell's (Mapleshade 56292). Not too many, it's true. But none that I love more, and none that are more perfectly recorded. As close to being in a club as you can get from your living room. I put on my favorite cut, Lush Life, the one with Maestro Jordan's only known vocal. I must have heard this CD a hundred times, and I am prepared to testify that never has Clifford Jordan sounded so real. The venue acoustic is so detailed, so finely wrought, you can see him standing there. Really. The finest nuances of sound, fully and accurately retrieved, that I have heard on my stereo.

Orchestral music is difficult to reproduce well in this venue. So I was curious how my stereo would fare with the RTP-4 on complex music. I chose the slow movement from Bruckner's Seventh Symphony (Gunter Wand conducting the Berlin Philharmonic, RCA 74321 68716 2), partly because it is music of unusually lush and rich texture, and partly because it is a stupendous performance. It is the only performance of the Seventh I've heard to equal (or exceed) the old Eduard van Beinum / Concertgebouw recording. Bruckner is never in a hurry to get somewhere, and the Adagio is nearly twenty-two minutes long. The effect of its ponderous evolution is intense and emotional, but deeply spiritual; it opens a vast door to a glorious other world. I'd swear the hair on my arms stood on end. More than once I had to remind myself to breathe, so mesmerizing was the experience. The textural detail is lusciously delineated, the architectural structure raised miraculously before me, glorious order from inchoate creation.

Ultimately, none of this is about the unending (and expensive) trudge to audio perfection. It is about the pleasure and joy of music. Music can be enjoyed on a cheap car radio, but the love of audiophiles for realistic sound seems to be a part of their skin. The RTP-4 retails for $2250, the Power Reference cord $600 for 1.5 meters. That comes to $2850 (before taxes): a fair wallop. Is it worth it? Yes. In my experience there are plenty of ways of spending nearly $3000 that would prove far less compelling and endearing. No CD player, amplifier, DAC or preamp that has passed these portals has done anything quite like it. It is a unique device. I find I can well believe those other reviewers who said it's the best power conditioner they've ever heard.


Acoustic Revive RTP-4

Outlets: 4

Type: Passive

Price: $2,250.00 US


Sekiguchi Machine Sales Co., LTD
3016-1 Tsunatori-machi
Gunma Pref. 372-0812
Tel. +81-270-24-0878

U.S. Distributor:

Joe Cohen
Lotus Group USA
Tel. (415) 897-8884