The apotheosis of an approach
Now in its fourth decade as a leading manufacturer of audio, video, data, and power cables, AudioQuest is somewhat of a rarity among makers of high-performance audio gear, and especially among makers of cables. Not only does AudioQuest explain in great detail on its website what it does, and why; it even offers exploded, cross-sectional illustrations of its designs. There is no snake oil at AudioQuest, no magic bullets or proprietary enchantments. Rather, in doggedly following founder-owner Bill Low’s ideal of do no harm, the AudioQuest team has tried to design and manufacture interconnects, speaker cables, and data cables that pass along the signal without altering it in any way, and power cords that satisfy power supplies’ desire for instantaneous current uncontaminated by the hash of radio-frequency interference (RFI) that pervades the power grid.
While Low is the first to admit that the ideal of a cable that perfectly transmits a signal is unattainable, that hasn’t stopped him and his team from trying. They’ve spent the past 30+ years distilling Low’s thoughts, single-variable experiments, and bypass tests into a handful of tenets about how to properly engineer cables. From solid-core conductors of metallurgic superiority to insulators with optimized dielectric characteristics, the process has been one of evolution, not revolution. With the William E. Low Signature series of cables, AudioQuest has raised its game, taking to the logical extreme everything it has learned to date about designing and making audio cables. In the World According to Bill Low, the WEL Signature models are not only the best that AudioQuest knows how to build, but the best available -- period.
When I learned that the 2012 edition of Jeff Fritz’s The World’s Best Audio System was to exclusively feature WEL Signature interconnects, speaker cables, and power cords, I wasn’t surprised. I’ve built my own reference system around a combination of AudioQuest products: WEL Signature speaker cables, Wild Blue Yonder interconnects, and Wild and NRG-100 power cables. In my experience, AQ’s line of cables offers industry-leading build quality, a tonal neutrality that seems to be universally applicable rather than system dependent, and provides incremental steps closer to that elusive ideal of perfect transmission as one ascends through the line. If I could afford to wire my reference system with nothing but WEL Signatures, I would do so in a heartbeat. (Though costly enough, the WEL Signatures are far from winning any Most Expensive Wire award.) But with no financial limitations being imposed on TWBAS 2012, we all get to live vicariously through this supersystem.
Let’s take a closer look at a few key aspects of AudioQuest’s top wiring models.
WEL Signature interconnects
The WEL Signature interconnect ($7500/pr. USD/first meter, $1350/pr. additional half-meter, balanced or single-ended) not only stays true to the fundamental AudioQuest tenets, but is conceptually identical to the Niagara, which until the recent introduction of Angel ($999/pr. first meter), was the lowest-priced pure-silver interconnect in the AQ line. Between Niagara and WEL Signature are Sky and Wild Blue Yonder, and all four models comprise the same conductors of Perfect-Surface Silver (PSS): a solid core of hyper-pure silver drawn and annealed through a novel process to create an exceptionally soft wire with a perfectly smooth, uncontaminated surface; and AQ’s patented Dielectric-Bias System (DBS), which all but eliminates dielectric memory by minimizing the storage and time- and frequency-smearing release of the passing signal. These interconnects differ in the size of the Air-Tube insulators that enclose the conductors, the implementation of their Noise-Dissipation Systems, and their RCA and XLR connectors. Each of these areas of difference deserves examination.
Air-Tubes: AudioQuest is not alone is stating that the best dielectric, or insulator, is no insulator (e.g., air, inert gases, or a quasi-vacuum). AudioQuest attempts to marry theoretical perfection to reality by surrounding its round, solid-core conductors with significantly larger-diameter Air-Tubes of the excellent insulator FEP (FEP is a Fluoro-Polymer which is chemically identical to Teflon, a registered DuPont trademark). The larger the Air-Tube, the less contact and dielectric interaction between conductor and insulator. The Air-Tubes in the Sky are 50% larger in diameter than those in the Niagara, and those in the Wild Blue Yonder are 32% larger still. The WEL Signature knocks them all out of the park with an Air-Tube diameter a full 142% larger than the Niagara’s. Bill Low admits that, with his conductors riding in a large Air-Tube, the twist rate of the conductors can’t be perfectly maintained, but he and AudioQuest compatriot Joe Harley, in a tag-team response to my question in this regard, said that while “variables such as constancy of the capacitance and inductance are minimally sacrificed for the sake of less dielectric involvement . . . with analog audio signals the advantage of having maximum air around the conductor completely trumps most considerations of absolute geometric precision.” To the AudioQuest team, the benefit of Air-Tubes reigns supreme in this battle of give and take.
Noise-Dissipation System:When I asked AudioQuest’s Steve Silberman what was the most overlooked aspect of their interconnect design, he responded immediately that it was the shielding. He thinks this is because almost every cable maker claims to shield their signal cables. Noise in the form of RFI is one of the mortal enemies of good sound, and today’s environment is more contaminated with RFI than ever before, due to the huge proliferation of RF-radiating devices such as computers and mobile phones. Most of AQ’s competitors, when shielding their cables, simply use a shield of foil or braided metal, which is almost always routed to ground. But AQ believes that “draining” RFI to ground causes a modulation of the ground plane, which in turn induces a form of signal modulation.
To greatly reduce the effects of such modulation, AQ takes a different approach, one somewhat analogous to constrained-layer damping. Their Noise-Dissipation System combines alternating layers of metal and carbon-loaded synthetics to prevent most RFI from ever reaching the equipment’s ground plane. The layers of carbon-loaded synthetic (C) have the ability to turn some of this RFI energy to heat and thus, very effectively, to “lose” it. Metal foil (F), used passively, is another way of dissipating and reducing incoming RFI. The result? Dramatically less modulation of the signal, less distortion, and better sound.
In the Niagara and in many of AudioQuest’s copper-conductor interconnects, a simple three-layer Noise-Dissipation System (F/C/F) is used. In the Sky, the system is bumped up to five layers (F/C/F/C/F). The Wild Blue Yonder and WEL Signature each have seven layers (F/C/F/C/F/C/F) -- which, according to Silberman, is the practical limit.
Connectors: The RCA and XLR connectors of the WEL Signature interconnect are not only striking in appearance, but precision engineered to remove any sonic character. The short story is that all conductive parts of the WEL Signature RCA and XLR connectors are precision machined from billets of C1100 electrolytic copper (aka “red copper”): high-conductivity, oxygen-free pure copper (99.94% pure Cu). These copper elements are directly plated with a thick (100µm) layer of silver in a process known as “hanging silver”: the part is hung over a vat of pure silver, then dipped into it. FEP is used as the main insulation material for both RCA and XLR connectors.
Using copper may sound common, but what people think of as copper is almost always an alloy -- a mixture of copper with some other metal or metals. Ask almost any machinist about machining pure copper (as opposed to an alloy), and he or she will likely tell you that it’s like machining clay -- can’t be done. However, as proven by the existence of WEL Signature RCA and XLR connectors, it can. According to Joe Harley, who claims to have tested just about every connector under the sun, “It sounds completely transparent -- one hell of a lot better than anything made from copper alloy.”
WEL Signature speaker cable
WEL Signature speaker cable ($11,200/3’ pair, $3200/additional foot) is the top model in AudioQuest’s new Tree series, whose four models share the same complex Double Counter-Spiral geometry, and are distinguished from one another only by their conductors. The Oak is the all-copper offering, in which AQ exclusively uses their most refined copper, which they call Perfect-Surface Copper+ (PSC+). The Redwood and Wild Wood use a combination of PSC+ and Perfect-Surface Silver (PSS) conductors, with Wild Wood having the greater proportion of silver. Finally, the WEL Signature speaker cable has conductors of 100% PSS. According to Harley, “The more PSS in the cable, the more that cable becomes invisible sonically, the more it gets out of the way. When you reach the rarefied level of pure PSS for all conductors, in the WEL Signature speaker cable, the cable becomes almost invisible. Nothing is perfect, we know that, but WEL Sig speaker cable is as close to not being there as anything we’ve ever heard.” I agree -- the shotgun double-biwire pair of 2.75’ WEL Signature speaker cables in my reference system reminds me daily of Bill Low’s achievements in no-holds-barred speaker cables.
I asked Low about the evolution of the speaker-cable geometries that have culminated in the Tree series, and found his response fascinating:
Prior to the mid-’90s, Richard Vandersteen had harassed me for a decade about how conductors crossing each other rather than being in parallel should work so much better. Yet I’d refused to make the suggested braided cable because, to me, they all sounded so very wrong and confused. Then I hit upon creating two tubes of conductors, one within the other, such that the positive layer could spiral in one direction and the negative layer in the other. Not only would local current flow in the positive and negative conductors run crosswise (not parallel), the overall energy fields for both positive and negative would be constant and nonchanging in relationship to each other. In high-frequency cables, braided geometry eventually causes no conductivity at high-enough frequencies (the problem is called “magnetic disruption,” from the strands crossing through the magnetic fields of other strands). The AQ Double Counter-Spiral geometry virtually eliminates this problem, while minimizing interaction and providing a nearly uniform relationship between a speaker cable’s significant fields.
In 1999, I brought out the first Counter-Spiral models. I later added DBS, finessed the conductor size and allocation a bit, etc. One unfortunate side-effect of the constant controlled proximity between the positive and negative conductors is that biwiring within a single Counter-Spiral cable simply doesn’t work. Biwiring works so well because there is so much advantage (reduced distortion) from eliminating the modulation of the treble conductors by bass energy, but within a Counter-Spiral cable, while the conductors can be attached to treble or bass separately, the fields of bass and treble cannot be separated. The reason for the Tree series is to eliminate this disadvantage while maintaining Counter-Spiral’s important advantages. I’m proud that the Trees are better full-range cables than their predecessors (thanks to various refinements), and are also ideal for single biwiring.
The WEL Signature speaker cable and all other Tree models feature the DBS system. They also feature the same combination of Spread-Spectrum Technology (different-gauged) conductors to avoid the particular distortion profile affecting a single-sized conductor. While radially symmetrical conductors (solid-round or tubular) have the fewest discontinuities, every specific diameter has its own sonic signature. Using a precise combination of four conductors of different gauges (which the initialism-prone folks at AQ call SST, for Spread-Spectrum Technology), a significant reduction in the audibility of such sonic signatures results, allowing for the WEL Signature’s exceptionally clear, clean, dynamic sound.
As noted by Low, the exact allocation of PSS silver conductors within the Tree series is an engineered art. If money is an object, he stresses that the Redwood, with a minority proportion of PSS conductors, achieves a very significant advantage over the Oak. The Wild Wood increases the PSS conductor count to further increase the sound quality, yet still costs much less than the WEL Signature. Nevertheless, AudioQuest joyfully proclaims the WEL’s advantage over the Wild Wood, for those who can afford it.
On the insulation front, rather than exclusively relying on FEP, the five negative conductors in the WEL Signature are insulated with partially conductive, carbon-loaded polyethylene. AQ has determined that this material damps RFI garbage, keeping it from feeding back into the amplifier, to provide the same sonic benefits that occur whenever RFI is reduced in an audio circuit: less grunge and better dimensionality.
As with the interconnects, the connectors terminating the WEL Signature speaker cable received special attention. Signature spade lugs (1/4” or 5/16") are also machined from pure C1100 electrolytic copper billet, then direct-plated with an ultrathick layer of silver. To provide a superior connection that ensures structural and electrical integrity, the connection between spade and conductors (as in the WEL interconnects and power cords) is made using AQ’s Cold-Weld System: a combination of high pressure at the point of contact and a paste impregnated with silver. By applying a controlled amount of pressure, the conductor and connector are mechanically made “as one” without the use of heat -- a practically perfect connection, in the eyes and ears of Low & Co.
WEL Signature AC power cables
The names of AudioQuest’s various power cables all include the letters NRG (pronounced energy). Like its speaker-cable cousin, the NRG WEL Signature AC power cable ($4050/first 3’, $950 additional foot) has 100% PSS conductors, arrayed in a Counter-Spiral HyperLitz geometry optimized for the transmission of a single frequency signal: the 50Hz or 60Hz sinewave of electrical power. The conductors are formed from three 13-gauge groupings, one each for positive, negative, and ground. Again, DBS is used, along with AQ’s multi-position, carbon-based Noise- and Crosstalk-Dissipation System (the NRG Wild and NRG WEL Signature receive more layers than their less extreme siblings), this time optimized for electric power-transmission duties. Custom Oyaide palladium over platinum-plated connectors are fused to the conductors in Cold-Weld style. In essence, the NRG WEL Signature differs from the NRG Wild only in its conductors. In comparing the performances of the NRG-100 (all PSC+ conductors) and NRG Wild (a combination of PSC+ and PSS), I was shocked to hear -- and prefer -- a distinct difference with the NRG Wild. I’m now in the process of upgrading all of my PCs to NRG Wilds, as finances allow.
I’m not sure I even want to know how much more can be attained with an all-silver NRG WEL Signature power cord. Ignorance is bliss . . . at least, until TWBAS 2012.
. . . Peter Roth
Manufacturer contact information:
2621 White Road
Irvine, CA 92614
Phone: (949) 585-0111
Fax: (949) 585-0333