Reviewing interconnect and speaker cable is the closest thing to latrine duty that an equipment reviewer can pull. To compare two sets of wires— your references (which in my case are mainly Nordost Valhalla) and the set under test—literally requires you to listen to a specific cut or two of a given record or CD, turn off all your equipment, get down on your hands and knees and dig into the jungle darkness behind your equipment rack—trying, sometimes by hand alone, to pull every RCA connector out of the jacks on the backs of your components and fit other RCA connectors into the exact same spots— then turn everything back on, let it warm up, listen to the same cut or two, and repeat the whole process maybe a dozen times or so.
Imagine my delight when Jeremy Bryan of MBL America told me that—if it weren’t too much trouble—he’d like me to try out an entirely different set of wires with MBL’s superb 101 Es and its equally superb electronics. And imagine how much my delight increased when I learned that these new wires were so expensive that virtually no one could afford them. I am talking about TARA Labs’ The Zero interconnect and Omega speaker cable, which, together, will put you out more than the vast majority of stereo systems (even the vast majority of expensive stereo systems).
The job of any interconnect or speaker cable is to carry an audio signal from one component to another without adding any sound of its own. Doesn’t seem like a tough task, does it? After all, wires are, uh, wires. And yet all you have to do is listen to two sets of cables or interconnects from different companies (or, for that matter, from the same company) to realize that wires invariably do add sonic signatures of their own—and that these signatures are at least as marked as those of other, seemingly more significant pieces of gear.
There have been all sorts of explanations for why this should be the case, from engineering geeks who claim the whole phenomenon is a mass hallucination (just as the different sounds of amplifiers are a mass hallucination) to finger-pointers who single out the material the wire is made of, its thickness or thinness, its geometry, its inherent electrical properties, the properties of the materials (called the “dielectric”) that insulate the positive and negative conductors from each other and from the shield that surrounds them, the properties of the shield itself (which is supposed to prevent the signal from being contaminated by RFI and EMI), or any combination of these usual suspects and a whole bunch of others.
As you might expect, cable manufacturers tend to emphasize those culprits that their products are designed to take care of. For instance, Nordost argues that the skin effect (the selfinductance of a conductor that causes nonlinear response in the high frequencies) and electrostatic-field interactions in large-diameter stranded cables are the chief problems, and that its flat, smalldiameter, solid-core designs fix them, drastically lowering capacitance and greatly improving transmission speed. Transparent Cable, on the other hand, argues that noise and the electrical mismatching of cables to different sources are the main issues, and that its complex networks and elaborate shields lower RFI/EMI, while, at the same time, calibrating the cable or interconnect to work ideally into a given load.
Like Nordost’s engineers, Matthew Bond, Chief Designer at TARA Labs, is fundamentally of the “lower capacitance school” of cable design, but with a difference. For him, thin is just half the answer because while thin conductors reduce the skin effect (and thereby linearize frequency response), they cannot carry current the way large-diameter conductors can (thereby reducing power delivery). His Rectangular Solid-Core conductors— made from “super-annealed,” oxygen- free, eight-nines copper—are designed to combine the flat frequency response of small conductors with the current-handling capability of large ones.
According to Bond—who has spent 18 years researching the subject—once conductor size and shape have been optimized, “the conductor spacing and geometry, and the materials used to insulate and isolate the conductors within the cable, will be the remaining factors that…create differences in the sound.”  With an interconnect, further reductions in capacitance (for even wider bandwidth and flatter frequency response) are achieved by increasing the distance between or among the conductors. However, if the conductors are positioned too widely apart and too close to the interconnect’s shield, then the RFI/EMI noise in the shield will couple to the conductors more readily. The trick, then, is spacing the conductors a sufficient distance apart to ensure high bandwidth, while simultaneously keeping them a sufficient distance from the shield to avoid contamination from RFI and EMI.