January 2014

Audiophile AC Power Outlet Comparisons
Oyaide, Synergistic Teslaplex, ACME, Hubbell IG 5362, cruzeFIRST Audio Maestro, and Furutech GTX.
Review By Jonathan Lo

  Most audio reviewers dislike writing cable reviews, especially if it involves comparing multiple cables, since the amount of time, effort, and concentration required makes it a laborious challenge. What is even more onerous? It has to be audiophile AC outlet comparative reviews because changing out outlets to compare outlet A to B to C, then back to A severely tests one's perseverance, patience, memory, and sanity. There is good reason one does not see this type of reviews very often, but it has to be done, so here it is.

The reason one cannot simply ignore AC outlets in the audio system is that they can make rather large differences in sound quality, as much as different cables, tubes, and even entire audio components can make. The fact these audiophile outlets tend to be relatively affordable compared to major components is the other reason audiophiles should experiment with them to find ones that synergize with their systems. However, it would be a mistake to assign absolute rankings to various outlets and expect the same results for different people's systems and tastes, so this article is an attempt to describe some sonic characteristics and personalities that others may find useful when they decide to choose outlets they would like to experiment with. In order to maximize the ease of comparison as well as to preserve consistency and repeatability, the outlets were installed in my DIY outlet boxes, which enabled fast switching.

Oyaide SWO-XXX
There has been a lot of ink spilt over Oyaide outlets. Since many audiophiles have tried the SWO-XXX and are familiar with their sound, they may be a good reference for comparing sound signatures. SWO-XXX, which is often thought of as their "palladium" outlet, utilizes highly polished deoxidized phorphor bronze as base metal, which is plated with 1.5 micron thick gold, then again plated with 0.3 micron of palladium. Oyaide has since come out with SWO-XXX Ultimo, which uses the same base metal and plating, without a clear explanation of what exactly has changed. Comparatively, SWO-DX series uses the same base metal plated with silver, then rhodium, while SWO-GX series is basically gold over gold, resulting in extra thick (2 micron) gold coating.

Audiophiles who have not experimented with "audiophile" AC outlets may be shocked at first to hear the sonic difference between a normal household AC outlet and Oyaide SWO-XXX, especially as the quality of AC outlets seems to keep going down in these new track homes being built. SWO-XXX will redefine what a mere outlet can do for "air" and "smoothness" in a system. There is oodles of air cushioning each sonic note and performer, seemingly lifting them upwards in the soundstage, while traces of brittleness, hardness, and grit are removed, resulting in a more liquid, smooth textures. Having a good amount of experience with palladium or platinum based conductors and cables, I recognize the great air and speed as a trait shared by both materials, usually with palladium sounding softer and smoother than platinum which tends to be airy yet more immediate, less soft. The final layer of palladium gives Oyaide R1 its unique flavor of smooth liquidity, which numerous audiophiles have loved and settled in with.

All is not perfect, however, as when one part of the sonic spectrum is so spectacularly noticeable, long-term listening usually bears out issues elsewhere. In the case of SWO-XXX, there is a sense that quite a bit of editorializing has been done to the sound, akin to photo's that have had slightly too much "photoshopping" done to them. One keeps thinking "this recording shouldn't sound this liquid" or "that note was never that airy." Also, the deep bass foundation appears to lose a bit of quantity and aggression. Now, many systems out there sound the exact opposite, i.e. rolled-off highs with dry textures and overblown bass, in which case SWO-XXX will do wonders to push those parameters the other end. SWO-XXX can certainly be an impressive life-saver for many systems out there, but as usual with these tweaks, try in your own system before deciding.

Oyaide R1
After the SWO series have become very popular, Oyaide rolled out the R1 as their premium AC outlet. While the SWO series starts out with phosphor bronze as the base metal, R1 uses beryllium copper as the base metal. What's the advantage of beryllium copper? To quote Be Cu Manufacturing Co, Inc:

"This malleability provides outstanding precision for critical miniature parts. However, unlike pure copper, beryllium-copper can be heat treated to harden the alloy into an extremely strong and durable metal. Stamped and formed shapes, such as springs, retain their performance characteristics for long spans of time. The inclusion of up to 2% of beryllium to copper enables the alloy to retain high electrical conductivity. Equally important, heat-treated beryllium-copper features excellent dimensional stability, fatigue resistance and corrosion resistance. Its strength is greater than ordinary copper alloys and many steels." 

Oyaide takes beryllium copper, polishes it highly, then plates it with platinum, then again with palladium. Basically, R1 uses platinum plating instead of gold plating stage of SWO-XXX while outside stays palladium. Platinum and platinum alloys in past have struck me as having a bit more immediate, resolved nature compared to palladium while still leaning to the fast, neutral mien instead of warm and romantic like gold. This trend bears out for R1, which sounds significantly more resolved, less soft, and less ethereal than SWO-XXX. There is more definition to images and more bass foundation compared to SWO-XXX. While many loved SWO-XXX after its release, there were some grumblings on the ‘net talking about how SWO-XXX was too cool or lean in their systems. The R1 should fit in more comfortably into many more systems, providing meaningful improvement over generic outlets. Compared to something more upfront and vivid like Teslaplex, R1 still has the Oyaide signature of refinement and liquidity, just not to the same degree as SWO.

Synergistic Research Teslaplex
The outlet under comparison is the original Teslaplex, which has since evolved into Teslaplex SE, which has different material for the back strap apparently. Reading about the Teslaplex outlet on the Synergistic Research website will likely cause a non-audiophile to burst into laughter or question whether it's April Fool's:

"The Synergistic Research TESLA Plex SE is our Quantum Tunneled duplex outlet. Quantum Tunneling is a process that changes the way a conductor works at the sub atomic level, impacting the entire TESLA Plex SE assembly. By applying a two million volt signal to each individual unit, at a specific pulse modulation and an ultra-high frequency, for an exact duration of time, we transform the outlet at the molecular level. This process is also performed on all TESLA Series cables, from Accelerator to Apex. The ‘before and after' is startling, with a lower noise floor and improvements in inner detail, air, low frequency extension, and overall transparency."

Yup, it's a tough pill to swallow even if you are an audiophile. Frankly, there is a lot of language on Synergistic's website that describes some incredulous stuff like active shielding for cable, "quantum" fuses, EnigmA valve power supply for active shielding, and Acoustic Art room resonance control cups. Putting all the baggage aside for a moment, the jist of Teslaplex seems to be zapping an outlet with very high voltage (two million volts) to change its sound. Well, what does that do?

Apparently, the extreme-voltage zapping really makes Teslaplex sound clear, vivid, and involving. This is not a ethereal, warm, or forgiving outlet; instead, it's very "open," super-resolving, crisp, dynamic, and engaging. In some systems that already accentuate upper-mids and lower-treble, it may even come across as unforgiving and bright, but in well-balanced systems, it is all about throwing away that veil and making music come alive. Perhaps because it tends to enhance edge-definition and highlight outlines, it seems to present more defined images to voices and instruments compared to outlets like Oyaide and ACME.

Its personality tends to suit tube-based systems better, especially the single-ended triode variety, when the main voice or instrument is helped to project energetically into the room with exciting clarity and bite. Still, as usual, one will need to be careful which components would work best with Teslaplex and how many is too many in one system.

ACME Audio Silver Plated Outlet
ACME Audio Labs outlet is definitely an "oldie but goodie." ACME takes the Pass and Seymour 5242 outlets, silver-plates the metal parts and screws, then cryo-treats whole thing.  The ACME outlet has been around a very long time, and while many other audiophile outlets have been brought to market since, it still sounds excellent while maintaining a budget price. The main hurdle to enjoying the ACME is the seemingly ridiculous amount of time it takes to break in, and it's probably a good idea to just install them into other rooms, connect some lights, refrigerator, etc, and just forget about them for a few weeks before actually installing them into the audio system.

If hastily installed and listened to right away, the ACME will likely introduce the proverbial Audio Hell to the owner, who will likely be disappointed and give up on this great outlet before the good stuff starts. At first, music will sound rigid, bright, rough, without any natural flow, and over the next few weeks, there will be a rollercoaster ride of improvement here and there while some things take a step forward then a step backward. When all said and done, the ACME presents a clear, resolute view into the recording with superb dynamics and definition. While it's probably not an outlet to use to soften and hide system faults, it will likely secure a place in a system, perhaps to feed some good tube amps, while another outlet that's a little more forgiving feeds the digital source, for example. It's difficult to beat the price-to-performance ratio of ACME outlets in this day and age when boutique outlets can cost an order of magnitude more.

Hubbell IG 5362 Double Cryo'd AC Outlet
Hubbell IG 5362 should not be confused with the regular Hubbell 5362. "IG" stands for Isolated Ground, and this model also happens to be built from phosphor bronze, which is very rare in non-audiophile, off-shelf outlets.

Unlike the ACME, which took an extremely long time to settle down, the Hubbell sounded good right out of the box and didn't exhibit much "nasties" during break-in. Compared to a "normal" household outlet, both IG5362 and ACME cleared away a veil, removing a ‘wooly gauze' over music. Images snapped into focus with better 3-D density. Bass was warm and popped with authority when called for, but not cyborg-uptight. While it is possible to imagine a system that is very rough around the edges that may benefit from the defocusing effect of a "regular" outlet, in order to extract that last 10% from the system, strategic use of good outlets is a must.

Compared to the double-cryo'd Hubbell, the ACME seemed to have a slight amount of glare and hardness riding on top of upper-midrange to low-treble area, which is an effect very similar to silver-plated solid-core copper wire relative to plain copper. It's not very noticeable with most music, but with music containing lots of energy in this area, such as a trumpet or female vocals at top of the range, there's a certain "tearing" effect with the ACME. Luckily, having used the ACME outlets for many years in various rooms, I can report that when they are truly well-used, like many months, this hardness eventually disappears, leaving a nicely extended, dynamic, clear-sounding outlet, if not exactly forgiving.

When thus fully burned-in, ACME can demonstrate what may be a bit of a problem with double-cryo'd Hubbell, which is a mild attenuation of frequency extension at the extreme top and bottom. IG 5362 probably has the most rich and bloomy midrange of all the outlets mentioned here, a delight and an almost tube-like response curve. Certain solid state or class-D amps with strong top and bottom response but somewhat reticent midrange may in fact pair beautifully with the Hubbell, as well as digital front-ends that exhibit similar subjective response. My personal reference systems revolve around tubes and refined digital sources, which is the reason my system synergizes better with Teslaplex and ACME.

cruzeFIRST Audio Maestro Outlet
cruzeFIRST Audio takes a completely different approach to audiophile outlets compared to a company like Oyaide. Their Maestro outlet eschews any plating, which cruzeFIRST Audio strongly believes benefits the unobstructed power flow. Instead, they concentrate on starting with sound materials by the way of commercial-spec outlet made to their specifications with high-purity copper/brass alloy. This is not a simple off-the-shelf outlet one can buy anywhere. This outlet then undergoes precise deep cryogenic treatment, special coating to reject RFI / EMI, then mechanical dampening applied. That's not all, as it then goes through a two-week break-in process before being sealed into its packaging.

The very first thought that occurred when plugging into the Maestro outlet was how supremely clean it sounded. It's not so much that other outlets did not sound clean before; many of them certainly sounded quite clean, especially when compared to run-of-the-mill household outlets. However, Maestro outlet seemed to open a new level of clean sonics that's revealed best in direct comparison. The lack of any plating may have something to do with this impression, among other factors, as there was almost a subliminal sense of less "stuff" between my ears and the music signal, less make-up and gloss being placed on music. This meant that less-than-perfect recordings with passages with some irritating texture or peaky brightness came through without these imperfections being thrust into one's face. They are still there but not as aggravating, which allows a deeper relaxation into one's favorite tunes, a boon for sure.

The second thought that came into mind was how delightfully natural the Maestro sounded. "Natural" is not exactly a heart-pounding, exciting description and is easily lost in the sea of audiophile verbiage; but it also happens to be one of the toughest attributes to achieve in an audio component. Take for example the Teslaplex, which at times comes across as more spot-lit, exciting, and engaging, which is a pleasing effect for many systems out there. Unfortunately, with certain recordings, it can have almost a "crispy" type of brightness which is unpleasant and distracting. The Maestro presents the performers a bit less forward and less thrusted toward the listener, more properly set back within the soundscape. There is less tension in the audio frequency "presence region" with the Maestro as well as a bit more natural bloom and weight in the mid-bass; as a result, some tracks that are overcooked and close-mic'ed are more enjoyable via Maestro, but all without losing true resolution or detailing because they are just slightly less forward. In fact, it is evident that the Maestro is neutral and natural enough to fit into a vast majority of audio systems out there without throwing off the system balance way too much, which cannot be said about many other audiophile outlets out there.

Some audiophiles might not be very impressed by an outlet that is described as "clean and natural," but that would be a mistake. The Maestro clearly has been painstakingly tweaked and optimized to arrive at those underappreciated goals, and what is truly wonderful is this outlet sounds natural because it is transparent, not because it smooths over details. It seems kind of odd to call an outlet transparent, but the Maestro certainly deserves that credit.

Furutech GTX-D Rhodium Outlet
The Furutech GTX-D is built like a jewel and sounds like it, too. Unfortunately, such quality does not come cheap, and those who are used to $1 light-weight, plasticky outlets used in most large residential developments these days may be somewhat shocked by the $239 price tag for the Furutech GTX-D Rhodium. Going straight to the source, Furutech, there are reasons their top-of-the-line outlet costs what it does.

In an ideal world, pure copper would be used for power connectors and outlets, but unfortunately, pure copper is quite soft and malleable, which would deform and loosen over repetitive use, leading to a potential disaster for AC power chain. This is the reason most power connectors and receptacles are made with materials with worse conductivity such as brass or phosphor bronze. Furutech has developed a technique that allows the use of their best conductor material, Alpha-treated pure copper, as the base conductor. Alpha-copper means being blessed with Furutech's patented cryogenic treatment and demagnetization process, good enough to be used in Furutech's premium signal cabling products. This copper is strengthened with nonmagnetic stainless steel spring system that maintains a very firm grip on power blades while avoiding damages to male connector blades. These receptacles receive the world-renowned Furutech rhodium or gold plating, becoming (r) or (g) versions of GTX-D.

Attention to detail does not stop there, and in order to minimize vibration and resonance, the receptacle body is made from a heavy-duty composite of nylon and fiberglass, which is impregnated with carbon powder and "piezo nano" ceramic. This technique is used to convert mechanical resonance into heat while performing shielding duties from EMI. Some of the other features include a curved pressure clamping system that increases surface contact area between the electrical line and the receptacle, accommodation for either spades or bare wire, special protective clamp cover, patented wire clamping system, nonmagnetic stainless steel mounting strap, and an anti-resonant rear dampening clamp.

If still not convinced regarding the price, one just needs to hold the GTX-D in his hand to realize this has to be the best built, most sturdy, meticulously thought-out, non-resonant piece of audio outlet available. Every moving part, screw, strap inspires confidence that this jewel will last for generations and still deliver. If still not convinced, one only needs to listen to it. Before listening to the Furutech, I was initially worried the rhodium plating may sound too analytical, which is the somewhat accepted reputation for rhodium; the corollary is that gold plating yields warm and euphonic sound. This description somewhat matches my previous experiences with these plating methods with other products, but GTX-D (r) managed to walk the fine line between resolution and warmth, while definitely avoiding any hash, grit, sheen, brightness, or harshness.

GTX-D achieved the highest levels of both resolution and smoothness, something usually not seen together in one product. If one switched from the $1 house outlet to GTX-D, the staggering amount of previously-unheard resolution, clarity, and dynamics will likely be startling to the listener. All that extra information and energy is delivered in a defined, controlled way, without various sound bites getting out of control and ragged as can happen with lesser outlets. Bass is not overblown or obscuring; instead, it is tight, defined, and extended with energetic dynamic punch. Tiny sounds from various nooks of soundstage come alive with crystalline and pure delivery while instrument positioning, layering, and depth become effortlessly obvious. To make matters worse (?), GTX-D delivers a gorgeous, tasteful, 3-dimensional solidity in the all-important midrange without going overboard with overly round and thick presentation. This outlet is not held back by a overly "balanced" but boring presentation with polite, reticent midrange presence, either. The voices have superb reach into the room and soundstage, vivid and forward enough to be engaging while not overcooked, especially in the sibilance and presence region.

What are the flaws? Well, Furutech must have a reason for making the gold plated version of GTX-D as well for a different flavor. Some of the Furutech vendors recommend the rhodium version for neutral to warm systems, probably with tubes, which may mean the gold version, may fit better in neutral to cool systems. Not having the GTX-D Gold in house to compare to Rhodium, it is difficult to say for sure, but going by prior experience with gold vs. rhodium plating, one might presume that GTX-D (g) might have a warmer tonality with possibly more bass quantity, albeit with less tightness. It may also have more forgiveness but not as much detail resolution. Would that make (r) version any less worthy and flawed? Any well-heeled audiophile would already know that systems are different and that one does not fit all. One outlet may serve a certain type of system better while the other outlet may synergize a little better with a different type of system, with final results heavily being dependent on the listener's personal tastes as well. Once again, there is no substitute for actually trying the product in one's own system, and for those audiophiles who are willing to pay the tariff and do the hard work, the Furutech should be on the rather short list.

Epilogue
After reading this article, hopefully the reader can refrain from asking the question, "But which one is the best?" The main purpose of this article was to pull together and organize many years' worth of personal experience with AC outlets while adding some newer ones to the experience base, not to find the "best" but to put subjective impressions into words before memory fades and plays tricks on an aging mind. As such, other people with different systems should not expect the exact same results for themselves, but rather, they should use this article as a starting point in an eventful and long-lasting journey into the AC power world.

Some well-heeled audiophiles may object to this article, citing that the specific power plugs and plating that are plugged into these AC outlets can influence the sound greatly. While this assertion is very true, for the purpose of this article, this effect is treated as part of the overall system balance to be considered. After all, the same thing can be said about using different tubes, cables, tweaks, and even components in a given system powered by outlet A, B, C, etc. Assembling a harmonious, outstanding audio system in its entirety has never been easy, and AC outlets are just one part of the often-mysterious puzzle that haunts us all. Let patience and love of music guide us through the maze.

Price & Company Information
Aoyaide Elect. Co., Ltd.
1-9-6 Yushima Bunkyo-ku,
Tokyo
113-0034 Japan

Website: www.Oyaide.com 
Oyaide SWO-XXX $110
Oyaide R1 $165

Synergistic Research, Inc.
17401 Armstrong Avenue
Suite 102
Irvine, CA 92614

Website: www.SynergisticResearch.com
Teslaplex $95

Acme Audio Labs
2480 McMillan Street
Eugene, OR. 97405
Website: www.AcmeAudioLabs.com
ACME outlet $40

Hubbell Incorporated
40 Waterview Drive
Shelton, CT 06484-1000

Website: www.Hubbell.com
Hubbell IG 5362 $25 (cryo extra)

cruzeFIRST Audio
Miramar, FL 33029
(888) 316-4121
Website: www.CruzefirstAudio.com 
cruzeFIRST Audio Maestro $85

Furutech Co., Ltd.
3F, 7-11-1 Nishi-Gotanada, Shinggawa-ku
Tokyo
141-0031 Japan

Website: www.Furutech.com
Furutech GTX-D (r) $240