December 1999

Essential Sound Products A/V Power-Flow Power Cord and A/V Power-Flow Pro Power Strip

by James Causey

A/V Power-Flow power cord A/V Power-Flow Pro power strip

Review Summary Sound Smooth and quiet, with dramatic improvements in soundstaging, dynamic range, and instrumental clarity; "the entire system became immediately more revealing, and also showed significant improvements in speed and pacing"; effective with video equipment too. Features Power cord uses stiff, grippy plug and IEC connector; power strip’s heavy aluminum chassis provides rigidity and shielding while sturdy outlets have tight mechanical grip on plugs. Use Slap them in anywhere you’re stuck with stock IEC cords or mass-market power strips; stiff cables keep themselves off the floor, while still being pliable enough for most practical uses. Value "If you could pay an extra 150 greenbacks to make your amp and CD player sound this much better when you buy them, you’d do it in a heartbeat."

Most people who have never experienced the sonic improvements afforded by high-end equipment (and many who have) are often shocked, astounded, or even disgusted by the prices we pay in our quest for musical ecstasy. You all know what I’m talking about -- the polite nods, the questioning looks, the guffawed questions: "You paid $3000 for a preamplifier? And it doesn’t even have a remote?" Once they hear your system, however, these questions normally turn into a respectful appreciation, or even a lustful conversion to the path of audiophilia.

There is one category of components that never fails to elicit shock, or even derision, from the uninitiated: cables. And above all other kinds of cabling, many amongst the infidel are forced into a stunned silence when you inform them that you’re reviewing power cords. "How can power cords make a difference?" they stammer.

Well, they can. The same electricity used to drive every output stage in your system, all the way out to the current which travels from your amplifier to manhandle your speaker drivers, originates at your wall jacks, traveling into your system along your power cords. If these cords color, distort, or interfere with that power, the music your equipment is trying to enchant you with will begin its journey to your ears already tainted, and we simply can’t have that.

Go with the flow

Michael Griffin of Essential Sound Products began his exploration into the design of power cords in 1993. Griffin, an electro-mechanical design engineer, was intrigued by the sonic differences he discerned, and began a quest to apply his talents to develop a cord of his own. After several months of tinkering with cord geometry, he traded a set of prototype cords to Ken Stevens, president of Convergent Audio Technology, in exchange for a set of replacement tubes for Griffin’s SL-1 Signature preamplifier. Stevens was impressed, and used them in his 1994 Winter CES demonstration room. This exposure led to a favorable review of ESP’s first production cord, The Essence (see Marc Mickelson’s review), and the rest was history.

The A/V Power-Flow products are ESP’s entry-level power cord and strip, using lower-cost versions of many of the technologies developed for The Essence power cord and Power Distributor. Each cord uses multiple conductors, each made up of many compacted strands, which ESP states allows each conductor to perform sonically like a solid conductor while maintaining the strength and flexibility of a stranded conductor. These conductors are arranged in a proprietary geometry, patented by ESP, which provides low impedance for maximum energy flow and sonic linearity through the entire audible range. ESP’s cabling is also carefully shielded to protect from electromagnetic interference (EMI) from external sources, and also to prevent the EMI generated by current flow within the cords themselves from causing distortion in nearby interconnect and speaker cables.

The A/V Power-Flow Pro power strip uses the same wiring technologies found within the power cords, including multi-conductor internal wiring and careful shielding. The chassis of the rather massive power strip is made from aluminum, and is carefully machined to provide maximum rigidity and resistance to potentially harmful resonance. The power strip includes six triple-wire outlets, which ESP claims were chosen for their superior conductivity and mechanical integrity. The power strip also includes a fast-blow 15-amp fuse that can be replaced by the user.

All current-carrying components in both the power cords and the strip are UL listed. The ESP A/V Power-Flow cords carry a list price of $149 USD for each two-meter cable, and the A/V Power-Flow Pro power strip is priced at $499 USD.

System hookup

The ESP cords arrived packaged in an attractive black cloth zip-bag carrying the ESP logo. Each cable has a sturdy IEC connector and massive three-prong outlet plug, whose conductors arrived protected with little plastic caps (I jokingly refer to them as "plug condoms"), a nice touch. The cables themselves are rather thick. They’re stiffer than stock cords, but still flexible enough to easily manipulate them through, behind, and around my equipment rack. The cords are just stiff enough to suspend in the air when connected to a component on my rack, which is handy for those who like to keep all their cables suspended above the floor for sonic purposes.

The power strip itself is a beefy aluminum monster with six sturdy outlets in three parallel-wired pairs. The strip mocked the other puny power strips in my house, being easily larger than my forearm, and its aluminum chassis taunted the flimsy plastic cases of my other outlet strips. Only the incredibly heavy UPS (Uninterruptible Power Supply) powering my computer system was not intimidated by the girth and mass of the ESP power strip.

I proceeded to swap out the stock power cords on my Parasound CD/P-1000 CD player and DNA-1 amplifier with the ESP cabling. (I currently use my TLC-1 line stage in the fully passive mode, and do not plug it into the wall.) Connection to both component and wall was simple, though the thick IEC connector needed a little encouragement to snugly connect to the CD player on the first try. In all cases, the connectors gripped firmly and tightly, with no hint of sagging or drooping.

The Power-Flow Pro outlet strip went into my A/V system in the living room, and I connected my Sony XBR television, Denon integrated amplifier, Pioneer LD and DV-515 DVD player, Hitachi VCR, and General Instruments digital TV decoder to it.

For reviewing purposes, all two-channel audio components rested on my Michael Green Designs Justarack, with the exception of my McCormack DNA-1 amplifier, which rested directly on a granite paving stone placed on my floor. A combination of Vibrapods and granite paving stones were used on components on the Justarack. Interconnects were the JPS Labs Ultraconductor and Kimber HERO, and speaker cables were the JPS Labs Ultraconductor as well. All listening was done with the Vandersteen 1C and B&W CDM2SE speakers. Gabby, the finicky audiophile feline, served as amplifier ballast and also provided your friendly reviewer with lovely racing stripes.

Sound off

According to ESP, power cords break in even when the equipment they’re connected to sits silent (but powered on), and the process accelerates when music is played. ESP recommends a minimum of 48-96 hours of playing time for complete break-in.

Being impatient to hear how the cords sounded, however, I performed some critical listening to my two-channel system as soon as the cords were hooked up (actually, more like an hour or two afterwards -- I like to give my equipment at least an hour to warm up before performing serious listening). The improvements in the system’s sound were immediately noticeable; the entire system became immediately more revealing, and also showed significant improvements in speed and pacing. Additionally, I noticed that forward-to-back soundstaging had dramatically improved (always a plus in my tiny listening room), with the layering of voices and instruments becoming more immediately discernable. The noise floor, always pleasantly low with the passive TLC-1, became even darker and less discernable, often dropping into absolute inaudibility. This is always a pleasure, as it helps unleash musical dynamics and allows me to listen to my system more quietly while still being fully involved in the music.

On "Rakim," the first track on Dead Can Dance’s Toward The Within [4AD 45769], these improvements were quite evident. The most dramatic change I noticed, however, was in sounds that transitioned across the soundstage, between the left and right channels; these transitions became significantly more fluid, moving distinctly within a layered group of instruments. In particular, these transitions took on less of a "left channel, now center, now right channel" presence, and instead seemed to smoothly sweep across my listening room.

I also spent some initial quality time with Our Time In Eden by 10,000 Maniacs [Elektra/Asylum 61385]. I had spent a great deal of time listening to this bittersweet Natalie Merchant vehicle at work on a pair of headphones, and was intimately familiar with its vocal and instrumental details. On this album, the most dramatic improvement came in the above-mentioned layering of instruments from front to back within the soundstage; the vast array of horns, string instruments, pianos, and voices was startlingly clear and clean. On both these albums, I also picked up a slightly drier tinge to high-timbre notes and effects, not enough to approach unpleasantness, but enough to call attention to itself.

Satisfied that the A/V Power-Flow cords were doing something, I turned to my home-theater system, where the power strip lay in wait. Pictures were clearly more 3D-looking, with the illusion of depth of field in well-shot scenes (on both DVD and LD) more apparent. The sound from my Denon integrated surround amp, driving the PSB 1000i floorstanders, was also noticeably improved, with cleaner and less-restricted dynamics.

I postponed all further critical listening until the cords and strip had more fully broken in; I played the two-channel system with the Power-Flow cords for over 150 hours, and used my home theater for more than 400 hours before re-evaluating the ESP components. (I did, however, enjoy many pleasant hours with music and movies.)

At this point, I began a series of painstaking experiments to compare the sound of the ESP cords in my two-channel system with that of the stock cords that came with my gear, and in particular, to distinguish the effect each had on my CD player and amplifier in turn. One of my favorite albums for evaluating a system’s performance is Ottmar Liebert and Luna Negra’s Viva! [Epic 66455]. The live album combines a superb recording that captures the venue’s space and sound with a passionate performance by the flamenco band. On "Buleria (Intro)" and "Black Stone Buleria," swapping out the Parasound CD/P-1000’s cord with an A/V Power-Flow provided distinct improvements in the sense of space, "thereness," and atmosphere, while also improving the transient snap of guitars and other acoustic instruments. Bass, particularly during the bass-guitar solos in "Black Stone Buleria," became deeper and carried more definition. Adding an A/V Power-Flow to the DNA-1 was even more dramatic, with a stunning drop in the perceived noise floor, and an incredible improvement in dynamic range.

Another favorite is Seal’s first album, Seal [Sire 2-26627] (not to be confused with his second album, Seal, or the recent bonus album, Seal). Though not quite up to the level of performance achieved on this second release, this first disc combines Seal’s remarkable pop talents with an ebullient production by Trevor Horn, which can often overpower an overly dry or ultra-revealing system. I feared the more revealing nature of the A/V Power-Flow cords would further emphasize these traits. When an ESP cord was used on the Parasound CD/P-1000, much of the hash and haze of the album disappeared with the drop in the noise floor, and there was a distinct smoothness and tightness newly apparent on both instruments and Seal’s voice. Dynamic transitions within the song, both moving from quiet moments to loud ones and in the reverse, were more dramatic, often making me catch my breath. Using an ESP cord with the amplifier was, again, the more significant change, with the production’s sense of atmosphere coming across far more clearly. Bass impact also took a significant turn for the rump-shaking, clearly denoting the A/V Power-Flow cord as a dance-music-fan’s delight. Bass tones became deeper, and carried more weight, while also becoming tighter and more distinct. The more revealing nature of the cord once again showed itself, however, as an enhanced sense of dry spittiness in Seal’s heavily processed vocal sibilants.

Next on my critical listening agenda was Joe Cool’s Blues, by Wynton and Ellis Marsalis (and their respective jazz ensembles) [Columbia/Sony 66880]. This wonderfully recorded album contains some fine performances of Vince Guaraldi’s famous Peanuts tunes, as well as some additional compositions by Wynton Marsalis himself. Hooking up an ESP power cord to the CD player drew out, in addition to the common improvements mentioned earlier, a more realistic representation of brass instruments, particularly Wynton’s trumpet and the trombones on track one, "Linus and Lucy." The brass tones were somewhat less forward and edgy, allowing the real weight and "blatt" of the instruments to come charging through. Pianos also carried more weight, and the imaging of instruments (both left-to-right and front-to-back) was clarified and reinforced. Most interestingly, the addition of the A/V Power-Flow cord to the Parasound player seemed actually to slow the performance; I was intrigued (and slightly disturbed) by this development, though it actually seemed to make the performance significantly more involving -- perhaps this slightly slower presentation was the more realistic one? Swapping in an A/V Power-Flow on the DNA-1 power amp made a further dramatic reduction in noise, and also helped percussion (particularly the hard-charging cymbals) to be more distinct and less strident.

Perhaps my favorite track for quickly evaluating the full range of a system’s performance is "Caught A Lite Sneeze" from Tori Amos’ Boys For Pele [Atlantic 82862] -- so much so, in fact, that even my non-audiophile friends know the track by heart from my demonstrations. This busy track contains a huge amount of detail, from Tori’s pants and howls to harpsichords, pianos, percussion, and a deep, pounding drum line. Using an ESP power cord on the Parasound helped to smooth the often strident cackles from Tori Amos, and also provided more snap and punch on percussion instruments. Once more, however, the A/V Power-Flow cords really shone when connected to the amplifier -- deep bass drums were instantly more detailed, carrying more weight and realism. Interestingly enough, Tori’s gasps and pants were de-emphasized by the addition of the A/V Power-Flow to the amplifier, making them less distracting to the performances as a whole.

The A/V Power-Flow Pro strip brought similar improvements to my home-theater system. The often-dark The Matrix was easier to watch, even in a bright room with a properly calibrated television, due to the distinct enhancements in detail three-dimensionality. Sound effects, particularly of gunfire, were more clearly rendered within the soundstage.

The ESP power strip also made great strides in the system’s musical performance; the just-released Depeche Mode DVD video compilation The Singles: 86 -> 98 sounded utterly fabulous, with the soundstage detaching itself cleanly from the plane of the front speakers, the driving bass and electronic instruments sounding more clear and distinct while also maintaining a sense of smoothness. Again, the noise floor (both audio and video) was dramatically reduced as well.

Conclusions

If you’ve read this far, you know that I definitely detected a number of distinct improvements to my systems’ audio and video performance when the A/V Power-Flow cords and strip were used. I unequivocally recommend their use, particularly over stock cords and el cheapo power strips, particularly at these prices -- if you could pay an extra 150 greenbacks to make your amp and CD player sound this much better when you buy them, you’d do it in a heartbeat.

The power strip, at $500, is a slightly more painful purchase to justify, particularly as it doesn’t include surge protection, but it’s a great way to wring even more clarity and performance from your system, particularly when you can’t remove those hard-wired crappy power cords to swap in the snazzy A/V Power-Flow cabling.

These cords will definitely help you to detect all those crazy audiophile and videophile nit-picks and doo-dads that we all love. But far more importantly, they’ll involve you even more deeply in your favorite performances. How cool is that?

...James Causey
james@soundstage.com

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