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With my customary €770 Entreq Challenger 2012 hoping for home-court advantages, at this juncture two further participants arrived. The cheekily named Unanimous uArt cable from Taiwan's KingRex takes the concept of divide'n'conquer from Acoustic Revive. It separates power and signal into physically discrete double-shielded legs like a Y. This uses two USB ports on the computer—one for the power, one for the signal leg—but combines at the DAC for business as usual.

Business as unusual comes from plugging the power lead not into the Mac/PC but instead the KingRex UPower battery supply. For DACs whose USB transceiver runs off buss power—unmodified hiFace and XMOS modules as in APL Hifi's NWO-M, the Eximus DP1 and Meitner MA-1 come to mind—this now delivers uncontaminated pure DC whilst computer power is eliminated entirely. Very clever!

KingRex sources their silver-plated oxygen-free copper conductors from WireWorld but adds cryogenic treatment. The plugs sport full aluminum shells and 24K gold-plated copper-alloy contacts. The cable geometry supports 480MBps in full compliance with the High-Speed USB2.0 standard. Pricing is $459 for a 2-meter length. In single form (power and signal lines combined) a 1m KingRex USB cable is $239, a 2m cable $269. With Acoustic Revive's dual cable at $895, KingRex offers theirs for essentially half.

Christine Wu of KingRex: "My boss wants users to take these USB cable home for a lower price. We make very little on these. I'm not sure whether Johnson will regret that decision. Our labor for the USB Y cable production is very very high. These cables are 100% hand-built in Taiwan. Adding the isolation netting, soldering, adjustments, damper fill, each technician can only do 3 straight or one Y-shaped cable in a working day. And you're correct, someone already owning the Acoustic Revive cable can still benefit from our UPower supply." The signal and power leads are marked with symbols on their casings. Invert them and there obviously won't be sound. Forget to charge the UPower and there won't be sound either. Then simply swap the power lead back to the computer until the batteries are live again.

From Taiwan too is the slinky black Telos Audio Design Gold Reference cable with four 26-gauge UPOOCC single-crystal copper conductors and dual copper-mesh shields, Teflon dielectric, two gold-plated metal barrels and PVC sleeving. It is available in 0.6m increments up to 4.8m. It had arrived together with their passive power block I'd reviewed separately. This is a very supple cable about which the manufacturer doesn't give more specifics.

Theoretical basics. Digital signal transmissions are influenced by jitter. Cable-induced jitter sources are disfigured square waves; impedance mismatches between conductor and connectors; dielectric energy storage and time-delayed release; and mechanical resonance. As civilians our ability to isolate jitter effects without confusing them with others is mostly zero. How would one strategically increase or decrease just jitter to learn what it sounds like? This keeps Robert Harley's old interview with Ed Meitner interesting. In it he asked the famous engineer just that. "I hear it as noise modulation on single sonic events. On a massed presentation I hear it as a lack of depth, as a lack of impact and dynamic contrast. On low-level passages I hear it as noise. It also produces a restriction of left-to-right image width. Overall it's a smaller picture, a more constricted picture that instead of fading into black fades into some kind of grey. Over time I get a headache and don't want to listen anymore. That's what I hear. When you look at what jitter does to the audio, it does most to the lowest frequencies and least to the highest frequencies. Because you accumulate many more sample points, the sensitivity to jitter is greater at low frequencies. It's wrong to look at the high-frequency part of the spectrum for trouble."

The review system consisted of my usual Eximus DP1 DAC/preamp run directly into Nelson Pass' groundbreaking FirstWatt SIT-1 monos to maintain utmost system simplicity. The amps drove 95dB sensitive €37.500/pr Boenicke Audio W-20 speakers, big solid-wood three-ways with Supratek tweeter, Supratek widebander, 12-inch sidefiring woofer and rear-firing ambient tweeter. Source was my iMac with PureMusic 1.86 in hybrid memory play with preallocation.