Power to the People
|Power to the People|
|Survey of Quality Power Cords from ElectraGlide, Magnan, Sahuaro, Shunyata and Tek-Line|
Noel T. Keen
1 December 1999
PO Box 26444
Phoenix, AZ 85068
602.943.2326; FAX 602.906.8716
Distributed by Audio Excellence, 940
E. Cavalier Dr., Phoenix, AZ 85014;
1224 W. Robidoux St.
Wilmington, CA 90744
"Any of the cords listed above can be counted on to give improved sound over stock power cords and represent good value for the money in view of the current technology."
NBS was one of the first companies to market improved (and generally expensive) after-market power cords for high-end audio components. It was ElectraGlide, however, that some two years ago led the way in providing cords which provided major improvements in sound quality. Subsequent developments have been rapid and we now have at least 20 companies selling power cords promising major improvements in sound quality as compared to the rather generic cords that are usually provided with audiophile gear. Accordingly, it was of interest to investigate some of the best of these. Over the course of what turned out to be a two-month exercise, I evaluated a total of 15 different after-market power cords. The initial reference points were the ElectraGlide ReferenceGlide Mk on digital (that I had used for about one year) and the Magnan Signature power cord/strip to the power amps, both run from dedicated lines. Several of the candidate cords failed to beat these references in my system.
About three weeks into the testing, I received the PS Audio Power Plant P300 (see my review and the follow by Frank Alles in StereoTimes.com). The P300 provided increased sound quality, but also provided a level playing field for the various power cords used with the Krell CD player (except, as noted below, the Magnan cords could not be used with the P300). The Power Plant 300 only provides 300 watts output and as such, it could also not be used with power cord tests on the KR amplifiers. These amps were plugged directly into a dedicated 20-amp wall outlet or to the existing Magnan Signature power cord/strip.
I did conventional ABA testing with short-term listening to selected CD tracks at identical volume levels (checked with an SPL meter) and longer term listening of several tracks from the same CD. This allowed assessment of the microsonic effects of particular power cords (clarity, resolution, etc. on particular short signature features, whether it be cymbals, drum strokes, a bass viol passage or whatever), as well as the macrosonics (how musical and ‘live’ the setup sounded, a summation of thousands of microsonic cues).
Software Tracks That Were Informative
Since testing was extensive, more than 100 CD tracks were used in this evaluation. Rather than insert references to particular CD tracks in the commentaries, the following were useful to assess the power cords. These tracks are all musical, relatively well recorded, provide good diagnostic cues to compare component and power cord effects and generally give systems a good workout:
A Taste of Violin, Jeremy Cohen, "In the blue" and other tracks (Clarity CCD 1012)
Flamenco Mystico, "Rondena para sabicas", (Golden String GSCD 016)
Ring Without Words, Wagner, track 10 from Gotterdammerung(Telarc CD-0154)
Tone Poems, "Good Old Mountain Dew" (Acoustic Disc, ACD10)
Lost Worlds, "Matawi: Killer of Men" (Hearts of Space, HS 11054-2)
Marin Marais, CD 1, track 8 of "Premier Livre de Pieces de Viole" (Ricercar 205842)
Brothers in Arms, Dire Straits, "Why worry" (Warner 9 25264-2)
Pan Pipes and Organ, "Doina de la domasnea" and other tracks (Cellier, Pv750001)
Dark Side of the Moon, "Brain damage" (Mobile Fideltiy, UDCD 517)
Folk Dancer, Muddy Waters, "Good morning school girl" (Mobile Fidelity UDCD 593)
James Newton Howard and Friends, "She" and "Amuseum" (Sheffield CD-23)
Chestnuts, "Hard Times Come Again No More" (Woodpecker, WP109CD)
Ultimate Demonstration Disc, several tracks, including 5, 11, 23, 25, 29 (Chesky UD95)
Café Blue, Patricia Barber, "What a shame" (Premonition Prem-737-2)
Das Heldenleben, Richard Strauss, Der Wischenvorhang (Ref Recordings, RR83CD)
C.I. Williams, "Because of you" (Mapleshade 04532)
Ronnie Earl and the Broadcasters, "Kansas City Monarch" (Audioquest AQ1018)
Wrecking Ball, Emmylou Harris, "Goodbye" (Warner 6180-4-2)
Here’s to Ben, Jacintha, "Danny boy" (Groove Note, GRV2001-2)
Power Cords to the Krell KPS 20-iL CD Player
In this phase, both the Krell amp and the KR monoblocks were used to drive the system full range. The Krell amp was powered with an IEC20 jumper from the Magnan Sig/strip and the KR amps were powered by various cords discussed below, either from a dedicated wall outlet or from the Sig/strip. I was surprised that all of the cords recommended below equaled or surpassed the reference ElectraGlide ReferenceGlide Mk II cord in my system. Notes with the Krell and KR amps driving the system full range were quite similar and so will not be differentiated. Because of their greater mid/treble resolution, however, the KR amps provided a more critical stage on which to assess the various cords.
Recommended Moderate Priced Cords
These cords all performed well in my system and benefited from use with the P300. The cords all gave similar sonic signatures when run from the P300, providing high resolution and detail, yet maintaining a high level of musicality. When plugged into the wall outlet, the SlipStream and Tek-Line cords exhibited a tendency to brightness on some material, but use of the P300 generally eliminated this. Readers, of course, should audition any candidate cords in there own room. The overall ranking of the three cords in this group was:
Tek-Line D12W —$399 Retail—Third
Two versions of this cord were supplied: the standard version ($299 retail) and the W version ($399 retail), which has a gold plated Watt-A-Gate gold line plug. While I used the W version in most listening tests, I could not distinguish particular differences between the two cords in my system. The cords are about ½ inch in width and solid but quite flexible. Construction seems first rate and professional.
The Tek-Line D12W gave less resolution than the SlipStream and less air and depth than the Black Mamba. Bass tended to be tight and very coherent, perhaps bettering the other two cords in this respect. On some material, such as the Flamenco Mystico track listed earlier, I preferred the D12 to the other two cords in this category. At its price, the D12 is a definite contender. It also beat several other cords that were judged to be of lower resolution and quality, that do not appear on this list.
Shunyata PowerSnakes Black Mamba —$699 Retail—Second
The PowerSnakes Black Mamba is a recent permutation of a power cord made by Shunyata. It uses the "Stardust" that is also present in the costlier King Cobra power cord, but only in a single layer. According to designer Caelin Gabriel, Stardust acts as a high frequency RFI trap, effectively removing this common power line contaminant. I will discuss more on the design philosophy of the PowerSnakes later. The Black Mamba is black, and one inch or slightly more in diameter. It is black, very flexible and easy to handle and has high quality but not gold terminals, one of which is a standard female IEC plug. The cord has a first class appearance.
The Black Mamba gave an excellent sense of air around instruments and very good instrumental and vocal presence. It was somewhat laid back on certain material and the level of resolution was generally not as high as the SlipStream. The Black Mamba was exceptionally musical and did not exhibit brightness under any circumstances. My notes consistently mention a sense of ease in musical presentation with this cord. It showed some of the same characteristics as the King Cobra, discussed below, but in fact falls far short of its performance level.
Sahuaro SlipStream —$599 Retail—First
This somewhat unusual cord uses a plastic mesh air dielectric "pod" near the IEC plug and this in turn plugs into a l/2 inch black, solid-core power cord, called a "tail" by Sahuaro, through a rather plain appearing standard AC plug. The cords are hand-built to desired lengths and terminations. Sahuaro offers a 60-day trial with full refund opportunity if you are not fully satisfied. An independent ground line crosses the pod and can be unplugged if the user elects to float ground on a component. Sahuaro recommends against using any PLC and suggests plugging the tails directly into a wall outlet. I used it both in this way and plugged into the PS Audio Power Plant 300.
Sahuaro has developed a white paper on their technology, excerpts of which I will mention here. The Sahuaro approach to power cords has been to use an air dielectric to remove energy absorbing materials near the conductors. The pod contains the hot and return wires surrounded by only minimal chemical insulation to retard oxidation. The remainder of the dielectric is air. Such a configuration is claimed to allow the electromagnetic field to expand externally, leaving the structure unhindered by field contamination. This is felt to facilitate electron flow through the conductors in a manner more free of compression, distortion, etc. Sahuaro cords are distributed through Sonic Excellence, noted earlier, and can be auditioned with a 60-day return policy.
The SlipStream gave excellent resolution with the CD player, with good soundstaging, detail, and articulation of the instruments and singers. The SlipStream could exhibit a tendency to brightness on some software when run from a wall plug, but this largely disappeared when run from the PS Audio Power Plant P300. The SlipStream did not present as lush and palpable a presentation or as great resolution as some of the higher priced cords, but is an excellent performer, irrespective of its price point.
Recommended Higher Priced Cords—Magnan Bronze & Shunyata King Cobra
The following two cords gave (as they should, in view of their price) performance that was generally above the three previous cords.
Magnan Bronze Power cord—$1400 Retail—Second
The bronze power cord employs very thin bronze ribbon-conductors with proprietary internal filtering devices at both ends. As with all Magnan products, the thin ribbons reduce phase errors. Because of the thin conductors, current draw is limited to one ampere. This in effect excludes its use with power amplifiers, but it is fine with preamps, CD players and other front end components that don’t draw much power. The Magnan bronze comes in a standard 8 foot length. The cable is very fat (ca. two inches, with a gray mesh outer jacket) as are the end pieces, even more so than the Signature cord. Standard IEC terminal plugs are supplied and outlet strips are not available. Soon after receiving the PS Audio Power Plant, I found that the Bronze and Signature cords were driving the P300 nuts. Plugging either cord into the P300 without connection to any component led to an indicated 140 watts on the P300 wattage output readout. This turned out to be due to the use of extensive capacitative filtering in the Bronze (and Signature) cords that interferes with the DSP AC signal oscillators of the P300. Therefore, the Magnan signature and Bronze cords were used only from a dedicated 20 amp wall plug or from the existing Magnan Signature cord/strip.
Despite the fact it could not be used with the P300, the Bronze cord to the Krell CD player elevated system performance above that with the three cords discussed above. The Bronze provided greater resolution and detail with all material played, a very low noise floor, and also imparted a great sense of ease to music. When run from a dedicated wall outlet, it could exhibit traces of brightness on some material. This tendency was largely eliminated when the Bronze cord was run from the Magnan Signature cord/strip, but dynamics also suffered somewhat in compensation. The Bronze cord gave very good tonality to my ears, on guitar strings, piano and voice. The Bronze is an excellent product that should be auditioned with first-class front end components.
Shunyata PowerSnakes King Cobra—$1995 Retail—First
"The PowerSnakes King Cobra was the star of the listening sessions on the Krell CD player. I try not to get too enthusiastic about products because you can never tell when something better will come along—either in the form of a "Mark 453" version from the same designer, or from another guy with a great idea.
This cord is designer, Caelin Gabriel’s, all-out, cost-no-object design. It is a recently introduced production model that is based on the "Anaconda" cord which was produced and sold in small numbers. The PowerSnakes King Cobra is a fat, jet black cord, about 1.5 inches in diameter. The body of the cord is quite flexible and has very flexible extensions at both ends that make connection to components and outlets easy. The bulk of the cord is enclosed in three successive layers of "Stardust," the proprietary anti-RFI material described above. The cord has high quality connectors, including a gold Watt-a-Gate AC plug.
Caelin is reluctant to disclose much of the technology involving pending patent applications, but states that the King Cobra contains 40 different parts, and considerable attention was directed to resonance damping and RFI/EMI control. Caelin raises the important issues of magnetic and electric field reactance and quantum field effects as being important in the quality of power delivery to components, and he de-emphasizes current delivery capability as being a prime problem. This regards not only the quality of power provided from the wall outlet (or the PLC, or whatever), but also degradative effects from the components themselves. In this regard, it is known that digital components have the proclivity to dump garbage back into the AC power line. Caelin maintains that his passive "Stardust" treatment absorbs much of this high frequency garbage, both from the power line and from components, to create a more placid and normal AC supply. He analogizes this situation to that of a stream running down a mountainside and then through a lower valley—on steep slopes the flow is rapid, deep and narrow, while on the level valley the flow is slow, wide and placid. Caelin says that what he tried to achieve in his power cords was to place the component in a quiet portion of the stream. The King Cobra can be used for front end components as well as high-current power amplifiers.
The PowerSnakes King Cobra was the star of the listening sessions on the Krell CD player. I try not to get too enthusiastic about products because you can never tell when something better will come along—either in the form of a "Mark 453" version from the same designer, or from another guy with a great idea. That can make you look pretty stupid for having raved over the "Mark 384" version. However, within the context of my system, the King Cobra cord to the CD player was special. It did things I’ve never heard from a power cord, enough to make even the most grizzled "cords don’t make a difference" illuminary grin a little bit. In some ways, the KC cord exhibits the character of the Black Mamba described above, with excellent presence and realism, but in reality, the King Cobra is a totally different animal. When compared to other cords, my listening notes continually referred to the lowered noise floor of the KC cord, greater spaciousness and depth of soundstage, and more presence and harmonic integrity. This cord tends to make the presentation from other cords powering the KPS 20-iL sound more congested and closed. Of the cords evaluated, the King Cobra alone had the ability to correctly place instruments in the soundstage and to integrate them with each other, creating a sense of reality and authenticity. It made the other cords seem somewhat "hifi-ish" by comparison.
The KC cords also imparted a great sense of what I call "air" around instruments and singers. These were given the sense of "living" or "breathing" that we take for granted in real life but seldom experience in recorded music. Reviewers frequently refer to the fact that in real life sound does not just come from the mouth of a singer as a point source. Instead, it resonates from the chest and oral cavity as well, creating a sort of 3-D hologram that we recognize as "live" The King Cobra created this illusion for me. The King Cobra could be described as lush, since it fills the soundstage with ambience and is "oh-so-good" at coaxing the CD player to portray a very analogue-like experience. Indeed, during my initial listening with the KC cord I thought, "oh-oh, with all this lushness are we missing a lot of detail/resolution?" But, no, repeated A/B comparisons with other cords convinced me that all the detail (and perhaps more) is there, but it is presented in a very natural and life-like way. This product is special—for those wanting the best on digital, look the PowerSnakes King Cobra over—it won’t bite.
Power Cords to Amplifiers
The class A KR Enterprise amps each draw at least 300 watts continuous power, and as such, cords must have good power carrying capacity. Extensive listening led me to recommend the cords above as the best of the lot at their particular price points. Compared to the stock cords, the various power cords made relatively less difference with the KR amps than they did with the Krell CD player. As indicated above, I could not use cords to the amps from the P300 Power Plant, so they were either plugged into a dedicated 20 amp wall circuit or into the Magnan signature cord/strip.
Magnan Signature—$800 Retail—Third
David Magnan has extensively researched interactions in AC power cord design, and this led to the Magnan Signature power cords, combining greatly reduced time dispersion ribbon conductors and proprietary built-in passive filtering. These cords combine micro-thin alloy and nonmetallic ribbon technologies with air space/TFE Teflon dielectric construction. The Signatures and the recently introduced Bronze, described below, are entirely hand made. The Signature power cord is claimed to improve all sonic parameters—greater resolution, image focus, dynamics, weight and impact, along with a much quieter background. CD playback is most improved, due to the particular sensitivity of digital timing jitter to noise on AC power. The cord comes in a standard 8 foot length, with shorter lengths claimed to diminish the beneficial effects. Longer lengths are available, as is a six outlet strip. Note the discussion below of capacitive filtering in the Sig cords and its effect on the PS Audio power Plant P300.
Shunyata PowerSnakes King Cobra—$1995 retail—Second
I will not repeat the technical details for the PowerSnakes King Cobra cords since they are covered above. Designer Caelin Gabriel states that they can be used anywhere in a high end system, and I found that they worked quite well with my power amplifiers. On the KR power amps, the King Cobra cords yielded some of the characteristics noted on the CD player, namely a sense of ease and musicality, with beneficial effects on soundstaging and depth, air and palpability. They performed better when run from a wall outlet as opposed to the Magnan Signature power cord/strip. The latter resulted in a suppression of dynamics and some reduction of the "airy" character of these cords.
ElectraGlide Fat Boy Gold—$2000 Retail—First
Designer Scott Hall’s latest effort with this highly regarded cord makes extensive use of gold throughout. Unlike the King Cobra, which uses gold plated Watt-a-Gate plugs; the Gold Fat Boy cord uses Leviton plugs and IEC connectors with 24 kt gold coating. Scott also strongly recommends that Fat Boy users invest in gold IEC male plugs on components and gold duplex AC outlet plugs, since he believes that these also make a major improvement in sound. The standard Fat Boy cords are short (only five feet), such that they would not reach my dedicated wall outlet, and had to be used with the Magnan Signature cord/strip. The newest Fat Boy cords have revised outer tubes; new damping controls; RFI/EMI filtration and the ribbon conductors are also sealed in a vacuum. Thus, while expensive, the new cords offer many features relative to the older versions that sold at the same price. Scott recommends that the Fat Boys only be used on preamps and power amps, but not digital components.
Listening trials were somewhat compromised because the Fat Boys were about a month late in arriving. However, after one week of constant break in with a 125 watt lightbulb, the Fat Boys provided excellent resolution with the KR amps, better than any other cord tried. During the first few days, this high level of resolution was accompanied by a tendency to brightness, but fortunately the brightness disappeared and the resolution remained.
Stewart Marcantoni at Weekend Environments in Port Orchard, Washington (360 874 1201) is a power cord fanatic and probably has more experience comparing them than most anyone else. He believes that power cords should in fact be considered as components and says that audiophiles should invest a substantial portion of their system cost (10-20% or more) on high quality cords. Stewart argues that the improvements in sound generally are greater than the same funds put into an upgraded CD player or other component. I tend to agree with him. Any of the cords listed above can be counted on to give improved sound over stock power cords and represent good value for the money in view of the current technology. While the degree of benefit will doubtless vary with systems and there may be better cords available at the various price points, the cords above should be on a short list for home audition by audiophiles thinking about upgrading their power cords.
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