Reviewer: John Potis
Digital source: Pioneer DV-535 DVD player feeding the Bel Canto DAC2
Analog Source: Sota Jewel, Sumiko Premier FT3, Micro Benz MC Silver, Bryston BP-1.5 phono stage
Preamp: Herron Audio VTSP-1A
Power Amp: Art Audio Carissa, Symphony II [for review], Herron Audio M150 & Bryston 7B-ST monoblocks
Speakers: Silverline Audio Sonata Series II, Magnepan MG 1.6QR, Silverline Audio Bolero [for review], Duevel Bella Luna Diamante [for review], Thiel CS 2.4 [for review] and Rethm The Third [for review]
Cables: JPS Labs Superconductor interconnects and speaker wire, DH Labs D-75 digital interconnect, JPS Power AC, Digital AC and Kaptivator power cords
Powerline conditioning: Audio Magic Stealth
Sundry accessories: Vibrapod Isolators
Room size: 12' by 16' with 9' ceiling. Speakers set up on long wall in quasi Audio Physic orientation
Review component retail: $99 for the Version 1, $299 for the Ultra-1

The very first time I became aware of ZCable's Z-Sleeves, I recoiled at the ridiculous nature of their claims. I thought I had finally heard the most preposterous claims for snake oil I'd likely ever encounter. The contention was that all you had to do was thread your cables through the sleeves, fire up your system, let it play for 24 hours and miraculous things would occur. Reality check: Don't bother listening for any changes for 24 hours - it took that long for the system to adjust itself to the sleeves. And since it takes the same amount of time to hear the system revert back to normal after you remove the sleeves, don't listen for any immediate changes then either. It was the ultimate claim! It was the perfectly evasive and ridiculous response to those who insist on the old double-blind A/B/X test of legitimacy. Don't even bother trying to A/B these things. They don't work that way. Ha ha. What a scam. Or so I thought.

But then the darned things started to crop up in the oddest of places. When Srajan reviewed the Balanced Power Technologies BP 3.5 Signature Ultra Isolator conditioner and declared it the best he'd ever heard and also popped the top to expose a Z-Sleeve prominently installed, I started to wonder. Obviously, others who should know better were not finding the Z-Sleeves completely implausible. So when the Zzzs became available for review, I decided to catch some.

Another reason for my piqued interest? I live in a house saturated with all kinds of spurious airborne debris. Pick up the phone on the second floor and listen to your favorite radio station. I'm serious!

I once came home in the afternoon to hear Rush Limbaugh emanating 60 dBs strong from the powered subwoofer section of a pair of speakers - with the rest of the system turned off but my little girl's ears liably not. After trying some power cords a couple of years ago, I became a believer in AC power delivery. Shortly after my purchase of a pair of Herron M150 mono power amplifiers, I tried a pair of JPS Labs Power AC cords and was astounded by what they did. Very shortly thereafter, I was contacted by Keith Herron and asked to return the amps. He was offering an internal change to make the amplifiers immune to RFI/EMI effects. Oddly enough, upon return I found my amplifiers completely immune to the effects of the JPS power cords. Obviously, something important was going on here. Shortly thereafter I reviewed the Audio Magic Stealth power conditioner and was sold on what proper care and feeding of the power lines could bring to a system.

The question I've had ever since is simply this: If the power cords leading to my components act as antennae to pick up all manner of airborne grunge, what about my interconnects and speaker wires? Surely they suffer the same assaults. So how do I protect or cleanse them? If there was going to be anything to these Z-Sleeves, they could just be the answer to my query. And to pre-reach my own conclusions, they were indeed. But they also were the source of my greatest frustration since I began writing about audio. As it turns out, the claim about the 24-hour period necessary for settling in is completely accurate. So too is Z-Cable's warning about the 24-hour "settling out" period. But I'm ahead of myself again. Since I'm no engineer nor have ever played one on TV, I asked Z-Cable's Mark Hampton to fill in the requisite technical tidbits. Here's what he wanted you to know:

The design of ZCable's Z-Sleeves really incorporates three different technologies.

  • Zero Gauss Chamber: A Zero Gauss Chamber (ZGC) is normally used by electrical engineers or technicians to calibrate Gauss meters and other devices which measure magnetic fields. It creates a work space internal to the chamber where magnetic fields are extremely diminished.

    A ZGC is made up of two or more concentrically spaced magnetic shields. Of all shapes, a cylindrical design is one of the most efficient to magnetically shield a finite space.

    The multiplying effect of successively spaced shields provides substantially greater magnetic attenuation than a shield of equivalent solid thickness.

    ZGCs can reach a saturation point of magnetic storage at which time their effectiveness is reduced. Hence part of the Z-Sleeve design was developed so as to reduce magnetic saturation by increasing the sleeve's ability to store magnetism.

  • Sleeve Harmonics: By putting a conductive sleeve around a signal or power cord, you will change its tonal balance and harmonics, period. It took me about 18 months to discover sleeve ratios of diameter, length and thickness which had balanced effects across the audio, digital and video spectrums. During this same testing, much investigation of metals, plated metals and metal alloys took place to achieve the best results.

    It should be noted that the tonal balance of a normal ZGC would be slow, thick and lacking in upper frequency detail. ZCable's research into sleeve harmonics has allowed us to use the inherent advantages of a ZGC while eliminating its drawbacks for audio applications.

  • ERS material: ERS material from Stillpoints is designed to absorb, diffuse and reflect EMI/RFI. Much reviewing and testing has already been done on the ERS material. However, no user of ERS has done more testing and development with this material than ZCable. We have determined ways to enhance the performance of the ERS cloth to many times of its own effectiveness. These enhancement methods are incorporated into the Z-Sleeves and also ZCable's Reference line of cables with onboard Z-Sleeve technology.

There is a synergy of design here. ZCable's special use of ERS increases the storage capacity of the Z-Sleeve to hold more magnetism. The ZGC design increases the ERS' ability to collect EMI/RFI. The higher shielding/rejection levels of our Ref1 and Ultra1 Z-Sleeve designs represent increased ability to collect, store and diffuse EMI/RFI.

It's important to note that a Z-Sleeve is more than just a shielding device. Instead, it organizes and purifies the signal. There is a simple test to demonstrate this. Take two otherwise identical speaker cables, one 10 ft long, the other 20. Hook them up and play a mono signal. Listen. The shorter speaker cable should be slightly better. Now put 2 Ultra1 Z-Sleeves on the longer cable near the speaker. If the Z-Sleeve were only a shield, you'd be merely shielding the cable's last 16 inches, ie. the length of the actual sleeve. The shorter speaker cable should still sound slightly better. Well, it won't. The longer speaker cable with 2 Ultra1 Z-Sleeves will sound noticeably better. It will sound less distorted, more natural, less synthetic and more tonally coherent. That's because the Z-Sleeve is a passive signal and power line conditioner.

Mark Hampton