ZCable’s Z-SLEEVE v1 Line Conditioner

ZCable’s Z-SLEEVE v1 Line Conditioner

The Premier Review of a Premier Product, or Bye Bye Gremlins

Paul Szabady

 13 August 2003


Passive Line Conditioner incorporating ERS cloth.
8 inches long, approximately 2 inches in diameter.
Price: $99 each (Available direct from Z-Cable)

7114 E. Douglas Ave.
Wichita, KS 67206 t 
Phone: 316 946 3762
Website: http://www.zcable.com
E-Mail: info@zcable.com

I am not a paranoid man by nature. I’m not prey to irrational fears about pernicious and deleterious emanations from the Earth, the sky or the Universe. So when I say that eliminating the effects of electro-magnetic interference and physical environmental resonance on a high-quality audio system is more important to the musical results than the components themselves, please don’t infer that I’ve joined the tinfoil-lined pointy hat brigade. Just because you’re not paranoid doesn’t mean that EMETICs (Electro-Magnetic Environmental and Terrestrial Interference and Corruption) aren’t out to get your system.

My investigations into (and reviews of) physical isolation devices and suppressors of electromagnetic interference over the last eight years or so have led me to a major paradigm shift: the sound of any component that has not been effectively mechanically and electro-magnetically isolated, is only delivering a fraction of what that component is capable of delivering, and is, thus, a distortion of its true merits. This leads me to discount the impressions I’ve had of any component, regardless of its quality, reputation or price that I have not heard in a state-of-the-art isolation context. The best of these devices have a greater impact on performance than a component upgrade. Indeed, a new component will face the same need for isolation. Many a seasoned music-loving audiophile has commented to me that they are less interested in switching to ‘better’ components than in extracting all the qualities of the system they already own. My experiences with the best of these EMETIC–taming products leads me to believe that most listeners have no idea of how truly good their systems really are … or can be.

The new Z-SLEEVE from ZCable offers an extremely effective method to deal with the EMI aspect of EMETICs. The Z-SLEEVE consists of a hollow, 8-inch long black cylinder, formed of a non-magnetic but conductive material, through which AC lines, interconnects and speaker cables pass. One simply slides the Z-SLEEVE over the line to be conditioned. There is a flexible rubber lip at each end of the cylinder. The Z-SLEEVE cylinder incorporates the sensational new ERS cloth (see my review of ERS in ‘Archives’.) Through a proprietary system of spacing the ERS cloth layers with an additional inner cylinder, the Z-SLEEVE isolates the cable from EMI pollution, thus producing a purer and less impeded transfer of energy along the cable. The more sleeves used on a given line, the more complete the isolation. It would be ideal to cover each cable completely. Applying only one sleeve to a cable will still be a distinct improvement (indeed, the improvement can be so great that one is loath to try more) but this is a rare case of ‘more is better.’

Though designed originally in conjunction with Z-Cable’s own line of interconnects, speaker cables, and AC cords, the Z-SLEEVES can be used with any cables. The only limitation might be some anaconda-like cables which may be too thick to slide through the Z-SLEEVE. For those whose experience with AC isolation transformers and AC regenerators has been mixed, the Z-SLEEVE instruction sheet recommends listening to the Z-SLEEVEs without them installed, and then later testing whether the further use of the more conventional AC conditioning is even necessary.

I tried the Z-SLEEVES on a large variety of cables of varying quality and price, in three different systems and with a variety of components (including 4 turntables, 3 phono stages, 2 CD Players, 4 preamps, and 3 amplifiers.) I focused first on interconnects, then on speaker cable, then on adding more Z-SLEEVES on a particular line until it was totally covered, and then on AC cords. The results were consistent, varying only in intensity and in degree.

Common to all these auditions was a reduction of artificially-bright background ‘hash’ and of the white harshness added to midrange and high frequencies. These most common effects of EMETICs are the notorious bane of many hi-fi systems. There emerged a far more natural rendition of tonality and timbre, the fundamentals of each note in proper balance with its overtone structure, resulting in a beauty and richness of tone with acoustic instruments that belied their electronic reproduction. Expunge ‘cold’, ‘clinical’ and ‘artificial’ from your vocabulary. Add ‘natural’, ’organic’ and ‘true-to-life.’

Consistent also was a similar improvement in the perception of detail, particularly in the conveyance of low-level detail. Extracting subtle low-level detail is one of the primary motivating factors for the purchase of high performance audio gear; unfortunately, it is also the first victim of EMETICs. While most vision-oriented audiophiles will enthuse about the improved sound-staging, depth and extra-musical sonic artifacts, fine low level detail resolution is much more important in its fundamental musical role: revealing a complete and accurate retrieval of musical performance and meaning. After all, each note begins and ends in silence and correct portrayal of the silence or space between notes is essential to create both melody and rhythm. Improved tracking of small volume changes in playing is essential to deeper musical communication, as is the ability to simultaneously portray different volume levels between instruments. I was struck by a renewed revelation of the intensity of emotion in the singing of Joe Cocker, Steve Winwood, Rod Stewart and Mike Harrison (of Spooky Tooth.) Nuances of extensively over-dubbed studio recordings were clearly articulated; realistic orchestral recordings revealed a vivid sense of instrumental place, soundstage reproduction, recording venue and overall verisimilitude. Improved too, was bass resolution and level, somewhat surprisingly. Best of all, the effects were not analytical or destructive of the overall aesthetic intent of the recording and performance. Nor was there any compromise of large dynamic swings and impact, a common flaw of more conventional AC line conditioning. The Z-Sleeve’s effects were consistently musical.

I was also most pleased by the effect on CD playback. The format has always been weak in low-level detail and any corruption of the signal immediately produces that canned and ersatz sound which has become the stereotype for ‘digital sound.’ I’ve had deep reservations about the format’s musical value since its inception and only with the advent of effective physical isolation—and now with the Z-SLEEVES guaranteeing no corruption of CD’s all-too delicate signal—have I begun to actually enjoy CD listening musically.

I’m tremendously impressed with the Z-Sleeves, not only with their effectiveness in dealing with the pernicious aspects of EMETICs, but more importantly, by their role in allowing a deeper and more affecting involvement into music. I congratulate Mark Hampton and the other folks at Z-Cable for this tremendous product, and give it the highest of recommendations. The last question I ask myself in the methodology of a review is “Do I HAVE to own the item?” Within ten minutes of my first audition, I already had the answer: Yes!

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