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Power cords + power strip
Oyaide TUNAMI GPX-R + MTS-4e

Price (in Poland): 3590 zł (1,8 m) + 3690 zł;
complete set: 21 640 zł

Manufacturer: Oyaide Elec. Co. Ltd.

Contact: Hayato Ishiguro
1-9-6 Yushima Bunkyo-ku, Tokyo | 113-0034, JAPAN
tel.: +81-3-5684-2151 fax: +81-3-5684-2150


Manufacturer’s website:
Polish website:

Country of origin: Japan

Product provided for testing by: MuSon Project, Inc.

Text: Wojciech Pacuła | Photos: Wojciech Pacuła
Translation: Andrzej Dziadowiec


Published: 1. February 2013, No. 105

The basic role of audio magazines is acting as a kind of filter (for audio products) and offering consultancy. The former means choosing from an avalanche of new audio products those that are most interesting, most innovative and best sounding. Consultancy role is focused on establishing on the basis of tests and reviews what kind of audio system a given component is most likely to sound best in; what’s worth buying and what’s not, what is a good match for something else and how to use it.
There is, however, one more duty that’s least spoken about – educational role. It doesn’t get much attention because specialized hobby magazines – such as audio – are governed by slightly different rules than traditional industry magazines. In our case, the research methods we use (auditions) are called into question and their results are undermined not on the basis of other results but in principle, by denying the very idea of such research.
Fortunately, one can point out a part of that educational role free from any politics – it is finding new audio brands and manufacturers, previously unknown in a given region. This is one of the areas that can only be served by transnational, i.e. published in English, Internet magazines. Srajan Ebaen with his “” has been doing that for many years; for the last several years we have been trying to do the same with “High Fidelity”. Since audio components from all over the world can now be delivered directly to the editor, they can be made known to and taken up by distributors in the country in which the magazine is registered. And if the distributors like them they will take care of making them available for the customer.
Being the “godfather” of these brands is a source of pride. This way gets realized the last and least tangible aspect of the role of audio magazines – the role of a promoter: of good habits, of good products, of interesting people and of interesting views. Our pride, among others, are: Leben, Acrolink, Musica, Gato Audio, Edit Audio, Entreq, HiFiMAN and other, now well-known brands in Poland. Not all of the manufacturers we present find a representative but it apparently needs to be so. Those, however, that stay become an important part of distributors offer. Among them a bright example is the Japanese brand Oyaide Electric Co. Ltd., having its registered office in the capital of Japan, Tokyo.

While I have known this company for years, since mid-2005 and our review of the 75AD Straight Line digital interconnect (published in September 2005, in “High Fidelity” issue no. 17), I met its owner, Mr. Satoru Murayama, for the first time this year, during High End 2012 in Munich. Soon afterwards we saw each other again in Poland – the head of Oyaide also came to Warsaw to Audio Show 2012. Even though we had no time to talk, we managed to shake hands and take a quick photo. We also agreed for an interview you will see published shortly.
But I already had at home, prepared by Mr. Murayama, top power cord system from his company comprising: four-socket MTS-4e power distribution strip (the version with six sockets is named MTS-6e; ‘E’ indicates the use of Schuko sockets) and five Tunami GPX-R power cords. Thus equipped, I was able to wire up all my system starting from the wall socket, through the CD player, preamplifier and power amplifier, and finishing on the headphone amplifier. A pleasant surprise was the autograph signed on the strip by its designer. And because it was a whole coherent system, showing internal logic in using the same conductors for the cables and for internal wiring of the strip and the same connector pins in power strip plugs and power strip sockets, I tested it as a whole system, replacing my own reference power cord system.

Oyaide in High Fidelity
  • AWARD OF THE YEAR 2006: Oyaide PR-02, TUNAMI Nigo, see HERE
  • REVIEW: Oyaide PR-02, TUNAMI NIGO, analog interconnect, power cord; see HERE
  • REVIEW: Oyaide Tunami GPX power cord, see HERE
  • REVIEW: Oyaide OR-800 ADVANCED speaker cable, see HERE
  • REVIEW: Oyaide STRAIGHT LINE 75AD digital interconnect, see HERE

    KSS meetings dedicated to mains supply and power cords

  • KRAKOW SONIC SOCIETY: meeting no. 50 - The mains (first part), see HERE,
  • KRAKOW SONIC SOCIETY: meeting no. 54 The mains (second part), see HERE
  • KRAKOW SONIC SOCIETY: meeting no. 73 - Acrolink Mexcel 7N-PC9100 vs. Acrolink Mexcel 7N-PC9300, see HERE

    A selection of recordings used during auditions

    • Random Trip, Nowe Nagrania, 005, CD + FLAC 24/44,1 (2012).
    • Ash Ra Tempel, Ash Ra Tempel, MG
    • ART/Belle, 101780, SHM-CD (1971/2010).
    • Ashra, Belle Aliance Plus, MG
    • ART/Belle, 121914-5, 2 x SHM-CD (1979/2012).
    • Bill Withers, Just As I Am, Columbia/Sony Music Japan, SICP-2633, "Natural Soul Collection", CD (1971/2010).
    • Carlo Gesualdo, Madrigali, dyr. Rinaldo Alessandrini, wyk. Concerto Italiano, Opus111/Naïve, OP30486 (2000).
    • Depeche Mode, Personal Jesus , Mute Records Ltd/ Sire/Reprise, 21328-2, maxi SP (1989).
    • Dominic Miller, Fourth Wall, Q-rious Music, QRM 108-2, CD (2006); reviewed HERE.
    • Jack Johnson, Sleep Through The Static, Brushfire records, 756055, CD (2008).
    • Jean-Michel Jarre, Magnetic Fields, Dreyfus Disques/Epic, EPC 488138 2, CD (1981/1997).
    • King Crimson, Lark's Tongues in Aspic, Atlantic/WHD Entertainment, IECP-20220/221, "40th Anniversary Series", 2 x HQCD (1973/2012).
    • Marc Copland & John Abercombie, Speak To Me, Pirouet Records, PIT3058, CD (2011).
    • Radiohead, The King Of Limbs, Ticker Tape Ltd, TICK001CDJ, Blu-spec CD (2011).
    • Schubert, Lieder, wyk. Dietrich Fischer-Dieskau, dyr. Gerald Moore, "Signature Collection", EMI, 55962 2, 4 x SACD/CD.
    • Stan Getz & Joao Gilberto, Getz/Gilberto, Verve/LIM, K2HD 036, silver-CD (1963/2010).
    Japanese editions available from

    Are you aware of the fact that the electric current flowing through your speaker coil, i.e. provided by your power amplifier is almost exactly the same as the current that comes from the wall socket? Contrary to our first impression, it is not the current nor even the voltage present on RCA or XLR outputs of a player or a turntable.
    In each house the path of electrical current starts with the distribution board with fuses. It is followed by a wire running to a power junction box and then if we are lucky the last wire to the wall socket. This is where we connect a power strip with plugged in power cords to power our audio system. If we are short on luck there are more junction boxes on the way where the wires are joined by screw clamps.
    Looking from this perspective and adding up all that happens before electric power gets to our house (additional fuses, power line, transformers, the grid), it is hard to believe, being of sound mind, that the power cord not to mention the power strip has any influence on the sound. Measurements do not help much either. The differences measured in well prepared tests, i.e. not simple checks to determine the basic parameters resulting from Ohm’s law but the tests that use variable signals as close as possible to the type of signal we deal with in music reproduction, are equivocal. They show changes but they are difficult to interpret.
    A properly prepared audition, though, demonstrates that something is going on; something that escapes classical evaluation. One can joke as much as one wants, there is no law against it, yet I know what I know – the power cord does influence the sound.
    So let me come back to the electrical current flowing through the speaker coil. It is almost exactly the same current that is delivered to our wall socket, hence its key importance to the sound. Via power cord it is supplied to the amplifier where it is usually initially filtered just next to the IEC socket and next sent to the primary winding of the. The transformer reduces the voltage which is taken from the secondary winding, rectified in the rectifier and then as DC filtered again in filtering circuits with resistors, capacitors and chokes before powering transistors or vacuum tubes. After transistors we have speaker terminals, speaker cable and a crossover. This is still the same current. Modulated, filtered (not fully though) of AC components, galvanically isolated in the transformer – still the same, though. The signal from the source only modulates the current flowing through transistors.

    The changes in the sound of my system when using various power cords and power strips are considerable and repetitive no matter the time of day or night. The last factor is important to power conditioners of the kind manufactured by Accuphase and PS Audio. Power cords and power strips are not susceptible to that, at least in my experience.
    That is why I put a special attention to set up a power distribution system that satisfies me – this is the best system consisting of the best components I know. I have a separate line drawn from the distribution board and dedicated to audio equipment, using Oyaide Tunami Nigo wire (9 meters). I also replaced an automatic circuit breaker with a regular fuse, one with wire and gold plated connectors. At the other end of power line I have three parallel coupled FT-SWS sockets with rhodium connectors from Furutech. Into one of them is plugged the Acrolink Mexcel 7N-PC9300 that powers the Acoustic Revive RTP-4EU Ultimate power strip. From there I use two of the same cords from Acrolink – to the CD player (2.5 m) and to the power amplifier (1.8 m). The preamplifier is powered by the Gigawatt LS-1 power cord. The cable that powers the power strip is clamped with the CNS-7000SZ Cable-Noise Stabilizer from Audio Replas (see HERE). I give you all that information so it would be easy for you to see what I change and what the implications are. Let me repeat – this is the best system I know. I did not change my mind after the visit of the Siltech Ruby Double Crown cable in my home (my review of the whole Siltech system can be found in the January issue of “”).

    I decided to treat the Oyaide cables as a whole system. Hence in one go I replaced everything – I plugged the Tunami GPX-R in one free Furutech wall socket to power the MTS-4e power distribution strip and from there I used three identical GPX-R cords to power all the components of my system – the CD player, the pre-amplifier and the power amplifier.

    The comparison was conducted on the basis of A/B/A tests where A and B were known, with ‘A’ being the reference system and ‘B’ the Oyaide system. The results were perfectly audible right from the start. There was no need to strain to hear them.

    Then I compared the Oyaide system to a generic “no name” power strip with thick computer power cords. This combination was plugged into the third Furutech wall socket. It allowed me to tell the difference from THIS end.

    The Oyaide system proved to be exceptionally smooth (to stick to a convention I won’t use the phrase “the sound was smooth” or “the sound changed in such and such way” – it would muddle the text and divert the attention from what is important). To be honest, I think that even the reference system is not that smooth or polished, so to speak. This does not refer to one or the other sub-range but to the whole frequency spectrum. With the Oyaide system we get perfectly balanced, which is equally important, sound flowing without any obstacles, irregularities or hoarseness. Provided our audio system is properly set up as well. While the Japanese cables will correct unnecessary brightness (although to a certain extent only) and graininess, the starting point is the system we have at our disposal.
    With a system which is transparent, dynamic and highly resolute as is the case with mine it is evident that the Oyaide modifies the sound in its own characteristic way. I have heard it repeatedly and it is no different now. The sound has less resolution than with the Acrolinks. The change is not as dramatic as with going from a 1,000 PLN to a 10,000 PLN CD player but audible nevertheless. It defines the perception of the whole. This gives the impression that after coming from the reference system the sound was quieter. I am almost positive that measurements would not show that unless we introduced an element dealing with energy spectrum analysis in particular sub-ranges. We would see then what I saw – everything seems warmer and a bit calmer. Lower bass is more shallow and synthetic bass from Random Trip album, particularly with 24-bit audio files played by the Ayon (CD-3s + NW-T) was focused a bit higher, mostly on upper bass. Higher midrange is smooth as hell. That will surface in all descriptions because this is the thing that lingers after auditions.

    The higher part of frequency range is perfectly coherent and resonant. It is also a bit stronger that with the Acrolinks. That is why, despite the fact that the sound is smooth and a little less dynamic that the reference, it is open. With badly set up systems where there is too much of high frequencies we would be torn between the beauty of midrange, the resonance and resolution of the treble (which is far above par) and the excessive energy of cymbals rich with sibilants – all of which is the worst junk in audio and should be avoided.
    This, however, won’t be the fault of cables but of the system. With a properly setup, maybe a little warm system the Oyaide will add something special to treble without brightening or glare. That “something” in my case added an extra layer, better selectivity. I had not complained before, yet the Tunami GPX-R showed class similar to one I heard with the Siltech Ruby Double Crown. It was cohesion, smoothness and, I will repeat myself, perfect selectivity. One can kill for such a thing, so to speak, for it is a place one cannot reach by simply replacing audio components or speakers. We won’t arrive there by polishing cables either – unless we arrive there by properly matching the power system all will be for nothing. Without this element it might seem that the Oyaide slows down the sound but this way – everything was alive and pretty.

    Comparison with the ultra-expensive reference system (about 100,000 PLN) easily demonstrates how the more expensive cables are better. However, as I mentioned already, even then the Oyaide provided us with something uniquely their own, something that could speak to their favor. If we are take into account the overall class of sound then the reference system fares far better, no doubt about that. It will be another story altogether when we consider a generic computer power cord and a generic power strip. Set against such background the Oyaide becomes the champion of champions. Now we can fully appreciate the fluidity of sound and its smooth inner cohesion. There is nothing that irks or irritates us. Even pretty strong treble proves resolute and selective without being excessively detailed. The computer cables sound hoarsely and primitive. The Oyaide presents aristocratic calmness and confidence of its high (that is, better) status.
    This calmness translates into contouring. With the Japanese cables from Mr. Satoru Murayama the contours are big and saturated. Although ultimately it is not the most selective sound I know, particularly in midrange and in lower regions, it still high resolute and hence very natural. The sound of an audio system with these cables is well organized and easy to absorb.
    Their questionable lower bass and lower treble resolution as well as a bit excessive energy of the latter require auditioning them at home in your own system in order to decide if that is what you are after. I am 99% sure that they will stay in your system because it is really difficult to find something that would reconcile two contradictory factors: smoothness verging on warmth and open treble. The MTS-4e power strip is especially worth recommending here. Somehow I have never written about it but I have been using it for two years now. It powers my headphone system with the Leben SC-300 SX [Custom Version] and the sources that are connected to it. It has never failed me both sonically and mechanically. If I am to recommend other products they are usually cheaper Supra and Gigawatt and only then the Acoustic Revive I use in my main system. I am under impression that the majority of other power strips (perhaps with the exception of Furutech and the Gigawatt PF-2 – I don’t know the new Mk2 version) is just snake oil and an attempt to pretend to be something that they are not.
    Oyaide is exceptional in that it comes up with innovative products of its own design and manufactured mostly in house. Products, we should add, excellent sonically and with matching workmanship. AC power plugs from this manufacturer are used by a greater part of high-end audio industry all over the world (if they can afford them, that is). This is true engineering backed up with an excellent ear. And not so otherworldly expensive to tell the truth.


    TUNAMI GPX-Re power cord

    Tunami GPX-R is a new version, with a better specification, of the Tunami GPX power cord known for years. The new cable is equipped with a special version of the Oyaide P/C-004 mains connectors called "Aspirin Snow White". The plugs are white and the cable is black, which gives a great artistic effect. Housing is made of thick polycarbonate, with rigidity and hardness that offer resistance to small vibration with high slew rate. Conductive parts are not made of phosphor bronze but of beryllium coated copper, providing better conductivity and mechanical integrity. The contacts are additionally coated with a layer of platinum and palladium.
    The cable is constructed of twisted PCOCC-A with a 5.5 mm2 cross-section. The cables are guaranteed for voltages up to 600 V and a maximum current flow of 30 A. To protect against noise Oyaide has designed a triple screen. It not only protects against external and internal distortions but also ensures the suppression of noise generated by conductors’ vibration.
    In the first layer electromagnetic waves are converted into heat. The second layer is made of semiconductor (a form of carbon), using its properties, consisting of discharging static electricity without affecting surrounding conductors. The third layer is a copper foil protecting against external noise. The whole is complemented by a “drain” wire placed close to the foil screen and connected to a protective conductor, improving the S/N ratio.

    MTS-4e power strip

    The strip housing is made of rigid sheets of high-grade stainless steel with repeatedly polished surface. Internal wiring is made of 4N 2 mm2 silver wire. Generally metals are subjected to accelerated aging process in order to prevent their stiffening. In this case the internal connections wires were only processed to eliminate surface oxidation.
    The power sockets are Oyaide top design, the SWO-XXX-E, with the body made of 30% glass filled PBT (Polybutylene Terephthalate). Particular attention was paid to connecting pins. They are made of deoxidized phosphor bronze coated with multiple layers of gold and palladium. Socket pins have a special, patented design, based on two spring elements and a very large contact area, ensuring extremely strong pressure. The IEC socket is also important which is why Oyaide used the high-end IEC 320 RR with contacts of silver- and rhodium-plated brass.

    The manufacturer lists the following strip’s characteristics:
    - The Dual-Spring vise design newly-developed for the top most expensive Oyaide sockets. Due to its strong holding power and 9 mm wide contact area, the contacts significantly reduce vibration at the contacts with no loss of signal transmission.
    - Sockets body is made of PBT (Polybutylene Terephthalate), filled with 30% glass mikrokuleczkami - it has excellent mechanical characteristics and fantastic dielectric properties,
    - The body has a special design with separately molded bottom and top, very effectively suppressing high frequencies. Small distance between the body and fixing pins additionally reduces vibrations
    - All the components ranging from the 6 mm thick contact down to stainless screws are made of non-magnetic materials
    - The chasses is made of highly rigid stainless non-magnetic SUS 304 steel. It protects not only from vibration but also electromagnetic waves and a very broad spectrum noise
    - Chassis damped from the inside with VEM 313 (Visco Elastic Material) damping material
    - Internal wiring is made of 2 mm 4N OFC copper
    - To separate the strip from the ground, it is placed on accurately machined brass spikes – a choice of four-point (default) or three-point support.

    SWD-XXX-e mains socket

    Although I have not mentioned that, we can also add to the whole set the wall socket costing (in Poland) 590 PLN. The SWD-XXX-e is made exactly the same way as the sockets on the strip. Its metal parts are made of oxygen-free phosphor bronze. The housing is made of 30% glass filled PBT (Polybutylene Terephthalate). The connectors are rated up to 240 V and 16 A. The contacts employ a special "dual-spring" configuration developed specifically for the SWO-E series. Due to its strong holding power and large 9 mm contact area, contact with the inserted pins is excellent and vibration further reduced. 30% glass-filled PBT was chosen because of its unique machining characteristics and electrical isolating properties. Since both the body and the base plate are made of one piece of the same material, high frequency vibration is reduced. Additional metal elements located at the back of the socket help to carry heat off the pins. Front is made of polypropylene with high mechanical resistance, further reducing the vibrations. Its smooth surface serves to improve product’s aesthetics. All the components, including fastening screws, are made of non-magnetic metals. The socket accepts wires up to 2.6 mm2.

    Distribution in Poland
    Eter Audio

    30-646 Kraków, ul. Malborska 24
    tel./fax: 12 655 75 43


    System odniesienia

    • odtwarzacz CD: Ancient Audio Lektor AIR V-edition (test TUTAJ)
    • przedwzmacniacz gramofonowy: RCM Audio Sensor Prelude IC (test TUTAJ)
    • przedwzmacniacz: Polaris III [Signature Version] + zasilacz AC Regenerator, (wersja z klasycznym zasilaczem, test TUTAJ)
    • końcówka mocy: Soulution 710
    • wzmacniacz zintegrowany: Leben CS300XS Custom Version (recenzja TUTAJ)
    • kolumny: Harbeth M40.1 Domestic (test TUTAJ)
    • podstawki pod kolumny: Acoustic Revive Custom Series Loudspeaker Stands
    • słuchawki: HiFiMan HE-6, Sennheiser HD800, AKG K701, Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro, wersja 600 Ω
      (recenzje TUTAJ, TUTAJ i TUTAJ)
    • interkonekty: CD-przedwzmacniacz: Acrolink Mexcel 7N-DA6300, artykuł TUTAJ, przedwzmacniacz-końcówka mocy: Acrolink 8N-A2080III Evo
      (test TUTAJ)
    • kable głośnikowe: Tara Labs Omega Onyx
    • kable zasilające: Acrolink Mexcel 7N-PC9300 (wszystkie elementy, recenzja TUTAJ) | Harmonix X-DC350M2R Improved-Version (recenzja TUTAJ)
    • listwa sieciowa: Acoustic Revive RTP-4eu Ultimate
    • stolik SolidBase IV Custom; opis TUTAJ
    • pod odtwarzaczem podkładki Ceraball (artykuł TUTAJ)
    • platforma antyrezonansowa Acoustic Revive RAF-48 (pod odtwarzaczem CD, recenzja TUTAJ)
    • platforma Pro Audio Bono pod wzmacniaczem Leben CS300 [Custom Version] (recenzja TUTAJ)
    • wkładki gramofonowe: Miyajima Laboratory KANSUI (test TUTAJ), Miyajima Laboratory SHIBATA (test TUTAJ), Denon DL-103SA (test TUTAJ)