Positive Feedback ISSUE 72
Silver Empowered Cord v2 - Third Time is the Charm
as reviewed by A. Colin Flood
I auditioned Igor Kuznetsoff's K Works Audiosilver power cord on four systems, including my big ole Klipsch corner Khorn loudspeakers. A fellow tweaking audiophile scoffed, "Who the hell would pay $350 for a power cord?"
Everybody knows that ones and zeros are just ones and zeroes, so therefore resistance, impedance, capacitance, distance, voltage, connection, and other electrical measurements of physical qualities could not possibly make a difference in cords and cables unless you paid too much for them! Right? How can a six-foot, $350 silver power cord really make a significant improvement in your high-end system?
A promo said Kuznetsoff's cords "punch way above their weight." Indeed, on the third system, classic Klipsch Khorns, like mine, switching to the Empowered cord produced almost as much difference as switching between the tube and solid-state amplifiers!
There were more texture and details, it was noticeable, and there was a difference. We all heard it. $350 is expensive for a power cord perhaps, unless it makes a material improvement in your already expensive system. It is hardly expensive for tweaking audiophiles who typically pay as much for their iPads. In fact, one tweaking audiophile, hearing sumptuous power cords like the KWA and the Clarus Crimson and Aqua cords, ordered a few others to try with his system—now he knows what he is missing!
Vichyssoise – Silver Soup
A cord is NOT the same as cable. A power cord connects via a plug. A cable is most often wires running side-by-side and bonded, twisted, or braided together to form a single assembly. A power cord is a connection just like patch cords and speaker cables.
Kuznetsoff supplies speaker cables, interconnect patch cords, line conditioners and accessory items. He builds his KWA Empowered Cords from flexible, user-friendly14-gauge wire. The difference between the original Empowered Cord and the current second version is the base wire used inside. The top of the Kuznetsoff KWA line, his Dynamo power cord, is hand built from individual OFC Litz copper conductors on layer-by-layer, where the second version (reviewed here) starts with a carefully chosen commercial cable.
The Empowered Cord starts with a thick and beefy high quality wall plug with enough room to include three small capacitors inside, a metalized-film type, and two Vishay High Voltage ceramics. The reason for a good outlet plug is obvious. The plug makes a good, solid, dependable connection. Beyond that, there is a limit to what an exotic "diminishing returns" plug can do after miles of wire and a large number of non-audiophile grade wire junctions along the way. Kuznetsoff chose these plugs for their sonic performance/value rather than hyped glamour. Each one is hand-polished and treated (both inside and out) with contact preservative.
Kuznetsoff quickly answered a dozen emails. He said the capacitors filter the incoming
power without any transient suppressive losses, right at the plug. They also stop equipment-originated digital noise from going the other way and reaching your other equipment.
The Empowered cord is shielded with a mildly conductive, but non-transient, suppressive Mylar-content, rough textured, silver braided cover that provides a "path of least resistance" to the radio frequencies (RF). The silver color is a coincidental by-product. The cover is Aluminized Mylar, which gives Kuznetsoff the non-suppressive (dynamically) partial shielding he designed. He says he doesn't "design primarily for eyewash, as many do. It just happens to be silver, and attractive to most, if a bit glitzy." Indeed, the shielding is quite attractive compared to the thin shiny stock black power cord. You feel as if you are getting a quality product simply by looking at and handling the Empowered Cord.
"While I do my best to turn out attractive products - regardless of the paradigms, our hairy-legged male audiophiles do shop with their eyes - never mind what they say. Still, it's the listening that counts," he says. "I suggest plugging everything together and running it, even if roughly, to let it all settle back down (I mean all your cabling, not just mine) so you can get useful results next week. Any disturbance/flexing of a cable costs some loss of burn-in (settling-down/redistribution/stabilization of charges within the dielectrics). When they are at rest, you get your best performance. This actually affects the interconnects far more than power cords due to the much smaller signal levels relative to the effect of the charges within the dielectrics—all of which is then followed by amplification."
The silver shielding cover is not electrically conductive to the touch. It connects to the plug's ground with a ground drain in order to "sink" the noise. At the wall outlet end, with the male plug, the silver shielding cover never stops. Yet at the other end, the shielding cover ends a few inches short of the IEC grade plug to guarantee that radio frequency noise cannot jump the gap to the equipment.
Kuznetsoff said this spaces the ferrite away far enough from the "equally carefully chosen and contact surface treated IEC connector to allow the cord to bend easily at the back of the equipment in order to avoid a wall or cabinet back." Included inside the IEC plug is a new hi-tech RF absorptive paper, ERS, to further strip away noise. A special low frequency-capable ferrite caps the end of the shielding cover to stop any RF from passing that way.
Not a Serious Substitute
"There are many types of ferrite formulations," Kuznetsoff said, "and the ones most commonly seen are meant to operate at much higher frequencies than are optimal for audio."
The result in the construction of the Empowered Cords is a sturdy, yet flexible, easy-to-use power cord that cleans up the power it carries and keeps it clean and RF free. Kuznetsoff said that while the cord is "not a substitute for serious megabuck power filtration, it will deliver an audibly cleaner noise floor, with the attendant improvement in dynamics this gives, and a cleaner, crisper soundstage and depth. The user-friendly flexibility avoids the problem of "bridging" or carrying vibration into equipment, which stiff cords will do, right past any isolation devices under the equipment."
Unlike some claims, Kuznetsoff said he did not find that "any amplifier is better served by a better power cord." A high quality solid-state amplifier did show differences between power cords more clearly, being generally more detailed and accurate, so it becomes important to serve some amplifiers quality power.
Does the size of the transformer matter? In other words, if I have a really large transformer, will the power cord be less important?
Capacitors Supply Short Transients
Yes, Kuznetsoff said, the size will certainly matter, with linear (as opposed to digital) amplifiers. A better current supply will improve dynamics for starters, regardless of how much supply filtering capacitance is available, since ultimately the transformer still has to replace what the circuit draws from the capacitors. It takes both to supply better.
Capacitors can supply short lasting transients well (while filtering rectified ripple, of course, but a transformer still helps), but, ultimately, under sustained crescendos, the supply voltage will sag if the transformer cannot re-supply that reservoir of power, and linearity is lost.
"Dynamics are the most telling difference between real and artificial," Kuznetsoff said, "a better sense of smooth, unforced, unstrained music, clearer empty spaces, better focus, larger soundstage and even better tonality is gained from a better transformer served by a better power cord, in addition to dynamics."
"Pretty much everything is improved!" The better the transformer, he said, "the more clearly it will show the quality of the power cord, so no, the power cord will certainly not be less important with a bigger trans. A bigger one is likely to want to draw more power more quickly."
Can the power cord influence the control of woofer impedance?
Damping and Current Draw
Yes, it can, Kuznetsoff said, if you mean control of the woofer motion that can be lost with loss of damping factor, especially under tough impedance minima. "If the cord cannot supply enough current, without inductive suppression, both quickly/sharply and continuously enough, the amplifier will lose some of its damping abilities, or the damping will not keep pace with the current draw, which will result in sloppy sounding distortion." This will result in poor sounding, inaccurate woofer performance—that loss of tightness, accuracy, and speed that are frequent complaints, in other words, woofer control. "Not to say the power cord is all that is responsible for this by any means," Kuznetsoff said, "just influential enough to say yes, it does."
Where you get the most benefit? From the front-end of the audio chain: the source, or the back-end: the power amplifiers?
They all benefit, Kuznetsoff says. "Which does most depends on the details of the circuitry. At the front-end, the best gain area is generally—but only generally—from improving noise floor, to generalize rather grossly. At the back-end, very generally but only generally, from improved dynamics and speed of leading transient rise. But it's never that simple or narrow a matter, always a mix of qualities, just most likely to be led by those factors in one or the other. Audiophile gear is finely tuned stuff with (hopefully) enough resolution to show up all sorts of quirks... er, excuse me, synergisms... to put it into audiophile-politically correct terms."
Would a quality power cord benefit a tube or a solid-state amplifier more?
This too depends on the peculiarities of individual circuits. It could be either but in some cases the ability of a solid state amp's power band extending into much higher frequencies can favor more benefit there from the filtering of RF.
Isn't a line conditioner more important for the entire equipment rack than a single power cord for just one component?
Power Cord Filtering
"Of course, and that's why I also make an excellent conditioner. But once you've filtered the incoming power, you still have to get it from the conditioner to the equipment without picking up fresh noise, or limiting transient rise/speed, etc. A properly set up system should have both. Having a whole system conditioner does not make my power cords redundant. And the person who does not have one at least gets filtering at the power cord, albeit a small filter. This is covered quite well in my white paper. It's really a good general document, as well as a descriptor of my power cord technology."
Delivery of orders depends on what's on hand. Kuznetsoff makes most of his 26+ products himself. As one-man operation, it is not possible for him to keep many of his designs stocked on shelves. Most of his products are made to order. For power cords, as little as one day to three before shipping, via Priority Mail, which is supposed to take no more than three days anywhere in the continental U.S. "So generally," he says, "the customer would receive a power cord within a week." Kuznetsoff does not have a website, preferring to sell through others.
Kuznetsoff's Six Rules for Power Cords
1. Must pass steady state current adequate to the task, or better, from an audiophile overkill view, without pushing the limits of the current handling of the gauge involved This means 14 gauge for all but the very largest amplifiers. Even 16 gauge for line level equipment is actually adequate for this, but it also:
2. Must not compress large instantaneous peak currents for any reason, either inductively (due to either the construction/layout of the conductors or inductors) or resistively (due usually to gauge).
3. Must keep the power supplied by a power filter device clean between that device and equipment the cord is powering. This means that:
4. The cord needs to be shielded from RF (Radio Frequency) interference, and a means of sinking, shorting, or otherwise disposing of that energy is necessary.
5. If there is no power filtering ahead of the power cord, then it must have some capability to filter incoming power itself in order to provide the cleanest power possible in every circumstance.
6. It should be flexible, of reasonable thickness, and reasonable to use. This is not just a matter of practical ergonomics. A stiff fire hose of a cord will bridge vibration noise past isolation bases and other quieting devices placed under equipment, rendering them less effective, if not pretty much ineffective in the worst cases.
That's all theory though, isn't it? Real world comparisons are what really matters. The car can go fast on paper, what happens when the rubber meets the road?
The first system I seriously auditioned the silver KWA snake on was a custom Harley Day set of Scanspeak cone drivers. This was a basically classic design. It was a narrow, solidly constructed tower but in a small, crowded narrow living room, relatively open on both sides. We swapped between the charming, white Glow Audio Two (EL84 tubes) and the amazingly capable Nelson Pass 10-watt stereo SIT-2 amplifier.
There was a lot more texture and differences with the Empowered Cord. At the low to moderate volumes of this relaxed audience (no hard pounding dance rock, darn it!), there were more differences between the silver KWA snake than the stock power cords with both amplifiers. Unfortunately, universal agreement was that the KWA snake was too bright, with more excitement or more edge, though with fuller bass, and more sustain to the cymbals. Like the difference between gold and silver interconnects, but not a warm improvement.
On Lightin' Hopkins' "Woke Up Old Lady" blues, at slow weighted C-scale volume in the low 80 SPLs, the KWA cord was bolder, more forward, so much so that one listener remarked it was "terrible." On Gregorio Paniagua's "La Folia," the KWA cord did seem more dynamic.
So I tried the silver snake on my babies, stock model Klipsch Khorns (AK-2 crossovers) in a large, bright, wood paneled living room with sloping cypress ceiling. Here the Big Ole Horn loudspeakers sit about 25' apart, and the sweet spot is twelve feet away. Yup, the KWA cord added edge to the cymbals. It was brighter, harder, but still lacked body. The KWA silver snake was a return to solid-state edginess. Despite its great name, the Empowered cord seemed, even on the SIT-2, less organic or fully formed. The percussion did seem quicker, perhaps a lot leaner too, but drum whacks on the snare seemed more electronically created than the natural rhythm taps. I am a "horns and tubes" man, so I did not feel that long term listening was possible with the SIT-2 and KWA cord combination.
On the Glow Amplifier Two and the KWA cord, once again the frequency response did seem flatter, but the combination removed the organic wholeness of the mid-range. The silver snake did add emphasis to the treble. It did seem to extend bass depth, with tighter, better-formed notes. I noted that adding a small sub or a vibration isolation platform for same price would make a more significant difference.
Third Time's the Charm
The integrated solid-state Synergy Control amplifier from Audio by Van Alstine (review coming) is a 100-watt per channel amplifier, with a rough textured cover almost like a popcorn ceiling. It has 47-K input impedance on all sources, for $1799. On another pair of Klipsch Khorns, the AVA amplifier was not lush sounding like the Roksan Capaisan, or powerful like the Jaton Operetta A2300AX Stereo Power Amplifier, or gentle like the renowned Outlaw 2150 receiver, yet it is a delightful and capable contender.
These Big Ole Horns were also far apart, in a large living room, in a medium size cabin, with exposed beam ceiling and wood walls, not surrounded by city. Here, the KWA snake was a game changer!
On Jacintha's "Willow Weep for Me," the amplifier and Empowered cord combination was noticeably smoother, with more definition, more delicacy. Her breath was readily apparent. It proved to be a synergistic combination.
So I tried the AVA amplifier and KWA cord on yet another system. This was Focal 836vs towers in a carpeted, square bedroom sized room, empty of all furniture except stereo equipment. The Focals are similar in appearance to the custom Harley Day towers mentioned above, except different! There are different drivers, cabinet, and crossovers. In short, although also multi-driver cone towers, they are nothing like the towers above. The 836V series is the largest of Focal 800V-series stereo pairs. The 836V has five drive units, and is a full three-way design, delivering its bass output from a substantial triple-ported, triple-driver array.
Here, too, the combination was much easier to listen to. I hated the KWA cord on two amplifiers on three home theater music and movie reproduction systems, but loved it on the AVA amplifier on fourth.
The KWA silver snake reduced the hardness to the treble range. It made the stock power cord seem sloppy, brighter, and harder. The stock cord sounded more like typical solid-state sound. The stock transients seemed too fast. The illusion of the 3D sonic holograph was flattened; instruments were reduced to background sounds instead of playing alongside of the lead vocals. The stock power cord seemed more live, but also more like a PA system. Perhaps a bit quicker, with more peaks, and less muted, possibly more active.
On two very different Big Ole Horn loudspeakers systems, in two very different rooms, with different tweaking audiophiles as listeners, the AVA amplifier and KWA combination was more organic and 3D, with more texture and a closer to live experience. It was more open with a larger soundstage, but felt a little filtered.
I have since heard wonderful and incredibly expensive Clarus Crimson and Aqua power cords on multiple systems. Think two and three times the price of the KWA snake. They sound really great, and never bad, on everything. Against a set of less expensive Shunyata Venom power cords (about $75), both red and blue-green versions of the Clarus cords blew the Venom cords away (review coming). The Clarus cords made similar differences on three different amplifiers and on two different cone speakers.
I don't have an explanation for the synergy we discovered between the AVA amplifier and the KWA cord. Neither did Frank Van Alstine himself. He didn't think the power cord would really matter that much. In this situation, the ones and zeroes can add up to a significant difference in power cords and cables. A six-foot, $350 silver power cord really did make a significant improvement in a high-end system.
When do you need a $350 power cord?
When it makes all the difference to the musicality of your system. On the AVA amplifier, listening with Kuznetsoff's Empowered silver snake was like adding the body of the saxophone to the black mouthpiece. A. Colin Flood
West Coast dealer
Brilliant Zen Audio