[SoundStage!]Synergizing with Greg Weaver
Back Issue Article
December 1998

Harmonic Technology Cable Satori - Is The Quest Over?

External influence

Any of you who have followed my writing know I have been on a quest to find the "perfect" cable (HA!) for some time now. The search began way back in 1977 when, after hooking up my first set of Monster Cable 10AWG speaker cables, I made the shocking discovery that a supposedly passive component in the audio chain did indeed make an enunciated difference. From that simple satori came the audio analyst’s third axiom, which simply contends that "cables are components!" I have tried everything I could get my grubby little paws on since that day over two decades ago. Shoot, I’ve even constructed my own cables when I wasn’t happy with what I could get. Factor in to that protracted search an e-mail I received from Albert Von Schweikert, who wrote me suggesting that I might want to check out a new cable company from San Diego called Harmonic Technology. The screen didn’t have a chance to cool down before I fired off an inquisitive e-mail of my own -- to Harm Tech.

Conceptual continuity

After communicating with Jim Wang, president of Harmonic Technology, it seemed that both he and the Harmonic Technology product designer, Robert Lee, had read my loudspeaker-cable treatment and were anxious to discover my reaction to their products. In that piece, which might be considered a good starting point for this next discussion, I noted that there are only four basic categories that can affect the resultant sound of a cable: the conductor material and purity, the dielectric material and purity, the construction geometry, and the terminations. The attribute which seems to make the biggest difference with the Harm Tech cables (Sorry Jim and Robert, I know you hate that -- but Harm Tech just rolls off the tongue so much more easily) is in how they address the production of the copper for their cables. Of course, the Harm Tech cables also incorporate excellent dielectric materials (Teflon and air-filled polypropylene), single solid-core Litz conductors, a twisted-pair pair geometry and extremely good locking terminations of their own design.

I think it very important to take a minute to talk about those locking RCA terminations. When tightening these locking barrels down, don’t use too much elbow grease -- and for two reasons. Just ask Greg Smith how hard they are to loosen after really clamping them down. Secondly, and more to the point here, in much the same manner as the placement of the sliding mass on Mike VansEvers Pandora power cord changes the flavor of the resultant sound, so too does the tension applied to the locking barrel. With the last couple of sets of cables I’ve used with this type of plug (like the excellent JPS products), I’ve experienced that the degree of tension used on the locking-RCA outer barrel can have a tremendous impact on the sound. Our own Doug Blackburn alerted me to this some time ago, and I have now found the effects to be very noticeable. I know that there are those of you out there who will think I’m at least one taco shy of a Mexican dinner special, but it is audible and, more to the point, controllable. The tighter you fasten them, the tighter the sound seems to become. Sounds take on a very pinched and strident character when over-tightened. Things like the soundstage presentation and image focus can be mucked up by too much tension as well. Once you have the interconnects inserted into you component, just turn the outer barrel (clockwise) until you feel the initial resistance telling you that you are starting to clamp onto the RCA jack. Then listen. An eighth to a quarter turn can create Hades or release heaven. Listen carefully. OK, you’ve been alerted to that foible, so let’s focus our attentions on the Harm Tech conductors.

Better wire manufacturers, and in fact almost all the ones who build audio-quality wire, use what has come to be known as oxygen-free high-conductivity copper, or OFHC. This quality of copper is also often referred to as "four nines" because its purity typically approaches 99.99%. This OFHC copper is still not perfect, but higher purity is a very desirable trait. If we take a look at the physical make up of a drawn copper wire, we see it consists of many separate grains of copper essentially stuck together in a long line. Impurities within the copper, including oxygen, silver, iron, sulfur, antimony, aluminum and arsenic coalesce at each grain surface, or boundary. This creates a much higher impedance to the electron flow by essentially forcing the electrons to have to jump those poorly conducting boundaries where grains touch. It's easy to see how reducing the impurity content and the number of grains per foot can make a wire a much more efficient conductor.

Most distortions heard and attributed to cables can be categorized into three groups. The first deals with frequency integrity, how accurately the high and low frequencies are transmitted throughout the conductor. The second deals with time-domain integrity, how the conductor affects the resultant arrival times of differing frequencies as they pass through the conductor. Highs are known to travel much faster through most conductors than do lows. The third is the dynamic capability of the conductor, how rapidly and consistently it responds to dynamic changes across the audio spectrum. Guess what -- reducing the impurities and grain structure in any cable will increase performance in every one of these categories.

The musical signal coursing through the wire repeatedly collides with all these impurities and boundaries. The sonic result is most often heard as harshness or brightness. It also contributes to the veiling effect and harmonic dullness heard with most of those cables. This enormous collision occurrence also results in some signals arriving at the speakers too early, and some arriving too late. Though minute, these differences destroy the true timing and subtle harmonic structure of the music. This attribute might be cited for the typically resonant and gritty sound. And, of course, these resistive and rectification effects will limit dynamics; in particular, those of the micro variety. And, as if that weren’t enough, it only gets worse. The oxygen content in most of these grades of wire will also allow for the very rapid progress of subsequent oxidation over time, further compounding all the previously mentioned problems.

Robert is quick to point out another sonic consequence that is a direct byproduct of the typical wire-drawing process. One Dr. Ohno, currently a professor in Canada but at the time a metallurgist in Japan, found that forcing a copper ingot through a die hole fractured the copper, creating stress cracks. When one forces the raw copper slug through the comparatively small die hole, the copper undergoes a molecular change due to the enormous stress followed by the rapid cool down. This process super heats the wire, and when it cools down rapidly, the copper crystallizes along the stress cracks. The crystalline barriers do not allow the electrons to flow unimpeded down the wire. The harmonic content of each signal packet is essentially sheared off by repeatedly smacking into those crystalline barriers. At the other end of the wire the signal is now fragmented, with the millions of signal fractals being uncorrected.

A cross-section of the wire, as seen through an electron-scanning microscope, shows that this typical drawing process inadvertently forms thousands of crystals. Most high-grade copper wires have from 400 to 500 crystal boundaries per foot, with your old basic zip cord having as many as 1500. As I also mention in my loudspeaker-cable piece, years ago AudioQuest had a conductor they called "functionally perfect copper," which was also drawn in a way that greatly reduced its impurity and boundary content. And the stuff might have been pretty good, but who knew? It cost more than my car.

Due to the significantly higher costs required to further refine the metal, this four-nines standard is where most manufacturers stop. Dr. Ohno engineered and patented this new methodology of casting the metal so that a single crystal is formed without stress cracks and crystalline barriers, virtually eliminating the crystal-barrier problem. They do it by slow-casting molten copper through a special preheated die. The necessary cooling of the single crystal filament is then done at a very slow rate, which also aids in eliminating the unwanted stress crystallization. In addition, he pioneered an inexpensive method of purifying the copper so that reaching the magic 99.9999997% purity level of theoretical perfection was now within reach. I don’t know exactly how they do it so cheaply (and we’ll get to the pricing shortly), but every one of you out there, raise your glass in thanks because a previously unaffordable yet extremely desirable audio conductor has been born.


The box arrived with the new conduits, and it took all my will power not to just leave work and go hook them up immediately. Now I know some of you will have a hard time with this, but power cords can make substantial differences. I substituted the new Pro-AC11 power cord for my standard Belden-type Pass Labs Aleph 3 cord, and lo and behold, there was a difference. Let the games begin.

What I noticed first was that there was a change in the treble character of the music, which initially seemed somewhat muted. With just a bit of time to analyze the difference I realized that I hadn’t lost any high-frequency information, but rather I was now hearing the addition of lower harmonic structure. This trait actually imparted a bronzier attribute to the cymbals and affected the overall flavor of the sound, mostly of the upper bass and midrange. There was a fill-in of harmonic structure that was quite evident on percussion instruments and strings.

Moving the power cord (I only received one to start with) from component to component revealed the change to be similar on every piece of equipment I tried it with. However, the most significant change came when I swapped the AC cable on the Dusty Vawter-modified Audio Alchemy Power Station Two. Wow! The hardness I had supposed inherent to the digital front-end dissipated considerably, which at first I took to be a loss of high-frequency integrity. With a little more listening I eventually have linked this attribute to being the correction of the lower-treble harmonics. This gave cymbals a better bronzy flavor, the upper strings more bite -- especially when played pizzicato -- and brought a more truthful vitality to trumpets, trombones and other metallic instruments. Listen to "Top Hat" from the delicious recording of the Andy McKee Quintet Sound Roots [Mapleshade 04432].

Here there seemed to be a noticeable enhancement of the lower registers as well. Bass seemed better defined in pitch, speed and location. For good examples, try "She’s Already Made Up Her Mind" from Lyle Lovett’s Joshua Judges Ruth [MCA/Curb MCAD 10475] or "What God Wants, Part III" from Roger Waters’ Amused To Death [Sony/Columbia CK 64426]. This was much more change than I would have expected from the lowly AC power cord, certainly more than from any others in my experience. I now have one Pro-AC11 on EVERY IEC socket in my system.

One of the Southern Maryland Irregulars thinks/thought wires made a difference, but they didn’t have the ability to disappear. He, like most of us, had learned to mix and match wire with other components, sort of like good cooking. Well, after trying just one of the Pro-AC11s, he described the effect it afforded his system as voodoo. Just one power cord, mind you. This from a self-proclaimed non-believer. Well, not for long. It seems that he bought into the voodoo and now has a whole Harm Tech system. Don’t ‘cha Curt?

121998truth-li.jpg (9658 bytes)Next I swapped out the interconnects between my amp and preamp. Here I had two options to try, the copper Truth-Link (pictured right) and the silver Pro-Silway. My original Truth-Link and Pro-Silway immediately were dubbed as the peppermint and spearmint cables, as the Truth-Link was cased in white with a spiral red stripe and the Pro-Silway was cased in white with a spiral green stripe. Jim has informed me that the cables are all now covered with the black webbing like my original Pro-9 Plus biwire speaker cables, achieving more visual continuity to the whole line.

What a transformation! I am able to say the Truth-Link has tremendously delicate detail and powerful resolve. They are wildly dynamic (in both the micro and macro departments), yielding the listener a greater ease in detecting differences in recording level, microphone differences/changes, recording techniques and venues. They offer a staggering reality to timbre, and presented the most wonderful balance, both in their presentation of harmonic structure and their rhythmic timing. This allows for a better-delineated soundstage and tightening of the image outlines without losing the air around instruments. Here again, the perception was of just a slight loss of upper-midrange to lower-treble information. But with just a few moments of listening, it becomes PAINFULLY apparent that what was missing before is now done ever so correctly. In short, overall tonality just seems more truthful, broad band, top to bottom. Truth-Link is a very apt name for the cables in my humble opinion.

My results with the Pro-Silway, while similar, were a bit over-pronounced. When substituting it for my preamp/power amp link, I found it just a bit too detailed and harsh with digital and lacking in bass extension and the fine pitch definition when compared to the Truth-Link. I didn’t mind those qualities as much with my 'table, where it translated into a sense of detail without harshness. But, depending on the record or disc, the Pro-Silway can be occasionally tilted clockwise with its balance. Only slightly so, but it is audible. The results were a slightly bass-shy and treble-hot flavor that added an unreal shimmer to the cymbals while missing the brass tone the Truth-Link had given the system.

Was this sonic difference between the Truth-Link and the Pro-Silway intentional? To find out, I pinged Robert and asked if this was done to compensate for the inherent difficulties some inexpensive tube and solid-state amps may have with fat, flabby bass and rolled-off high-frequency performance. Robert replied that the Pro-Silway has different purposes. He went on to say that he has noticed that a lot of American-made speakers have exaggerated low and mid-low frequencies and are rolled off a little bit in the high-frequency region. Hmmm. I think my idea about tubes might make more sense.

Next up were the digital cables. Once again, I had the luxury of both experimenting with both the Cyber-Link Silver OCC and the Cyber-Link Copper OCC. This was a tougher call, but once again, the copper eventually won out -- for much the same reasons: more accurate shadings in timbre and dynamics. The Cyber-Link Silver OCC was great with well-balanced and carefully mastered discs, which in my experience are too few and far between. With the common mastering job afforded most recordings, it was a bit too aggressive. But I like having the ability to use it when the source permits.

121998pro9plu.jpg (13272 bytes)It was time for the final conduit substitution, the Pro-9 Plus biwires. It is no secret that I feel this to be the most crucial interface in any music system. Well, these bloody things offer the most vivid yet realistic soundstage and stable phantom image I’ve yet experienced. The Pro-9 Plus just compound the positive effect of all the aforementioned qualities. There is a vibrancy and vitality to the music that was just somehow missing prior to their insertion. Overall tonal balance and timbre is rendered more truthfully, top to bottom. The ability of these cables to render micro and MACRO dynamics is unnerving.

For micro dynamics, try listening to Mark Knopfler as he sings at a minute into "Fade To Black" from Dire Straits On Every Street [Warner Bros. 26680]. The breathy "P" sound created by the expulsion of air from his mouth when it hits the microphone just explodes into the room. Their resolve of low-level detail is staggering, no doubt in part due to their micro-dynamic capability. For the macro test, listen to the closing seconds of "Late Home Tonight, Part II" from the Roger Waters Q Sound extravaganza Amused To Death [Sony/Columbia CK 64426]. The explosion at the end of the track literally rolls through my room. It starts behind the speakers, hits me like a wave at my chair and then billows on out behind me. Watch the volume setting here.

Stage and image specificity have never been better, as both enlarge to a more realistic presentation in their size, space and location, yet become even more focused in the acoustic. The venue size becomes clear, and the back corners of the soundstage are more fully illuminated. Try the now near-religious experience served up with "Spanseniye sodelal" from the Turtle Creek Chorale’s offering Postcards [Reference Recordings RR-61]. In a word, these cables just disappear, allowing the music to fully emerge.


Can you say synergy? I hope you can, as this is the whole point of this monthly rambling. These cables, taken together, are simply the most honest-sounding cables I’ve ever experienced in my system -- regardless of price. Read that again ‘cause I’m not kidding. I want to stress that your actual mileage may vary, BUT in every application I’ve dropped them into in the last two months, with every component and speaker I’ve had to play with, I’ve heard the same things. This leads me to believe that the results should travel well. They simply seem to get out of the way and let the music just "be."

121998proac11.jpg (12480 bytes)OK, you say. But at what cost can I have all this sonic nirvana, refinement and magic; how much to own a system of cables that offer nothing to the sound coursing through them? Well, loyal readers, I’ve saved the best for last. The power cables come on the heels of some others that carried price tags over $500. Yet the Pro-AC11 comes in a two-meter length, finished with either the Leviton male plug for $170 or the Hubble male plug for only $10 more. Yet single-handedly, the Pro-AC11 can ignite even the most unassuming amp, preamp or digital front-end.

My previous choice for interconnects were the outstanding $300 JPS Superconductors or my under-$20-a-set home-brew SSTs. I have heard interconnects that weren’t anywhere near this truthful, yet cost over $1000 a meter. The Truth-Link retails for $249 in a one-meter set and $351 for a two-meter set. The Pro-Silway goes for about a hundred bucks more per set. And Harm Tech has a budget interconnect (which I’ve yet to hear), the Precision-Link, also a single-crystal conductor design, starting at just $129 for a meter set.

While the one-meter Cyber-Link Silver ($199) and Copper (just $99) are both excellent by themselves, when combined with the Harm Tech system, the synergy is overwhelming. And folks, they dethrone loads of other digital cables I have on hand, some costing upwards of $300.

The best speaker-cable combination I had found until the Harm Techs crossed my threshold was the Goertz Alpha-Core MI-2 copper biwires shotgunned to the woofer cabinets and the AG-1 solid-silver biwires shotgunned to the mid/tweeter cabinets of my Von Schweikert Research VR 4 Generation IIs. The cost? Just over $2k. The Pro-9 Plus biwire eight-foot pair retails for just $888.

So is my cable quest forever quelled? Hard to say. But for now, I have my new reference system. I would urge any of you considering a cable purchase to seek out and hear the Harmonic Technology products before you commit your hard-earned green to anything else. And I want to stress the term system here. Harmonic Technology -- remember the name. You’re likely to hear a lot more about this company. The sum performance of this new, single-crystal line of cable is unsurpassed in my near 20-year quest.

...Greg Weaver

Harmonic Technology
Prices: Pro-9 Plus bi-wire speaker cable, 8 foot - $888 pair; Truth-Link Interconect, 1 meter RCA terminated - $249 pair; Pro AC-311 CL-3, 2 meter Hubble male plug - $180; please visit their website for other models and pricing options

Harmonic Technology
12781 Legacy Place
San Diego, CA 92131
Phone: 619-578-7788
Fax: 619-586-7918

E-mail: harmonic@san.rr.com
Website: www.harmonictech.com

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