Allnic Audio’s Kang Su Park is a well-respected South Korean vacuum tube designer. To his name and under his belt are many amps, preamps, DACs and phono stages. Yet today’s review is about cables. “So,” you think dismissively, “active cables with valves then?” Not. Mr. Park is a serious engineer, not a jester. His ZL for zero-loss cable line is simply an attempt to apply solid engineering to prevailing signal-transmission challenges. To reduce contact resistance between a conductor and its termination, he eliminates solder and hot-welds at 3’000A/1000°C [right]. This creates a molecular merger and single material at the transition point. With it he claims conductivity far superior to even the best boutique solder. To eliminate not just electrical but magnetic noise for his digital and analog interconnects, he runs mu-metal shielding*, the same nickel alloy which traditionally shields noise-critical transformers like phono step-ups. To improve contact pressure, he uses special heat-treated Beryllium-copper sleeves, double-bladed spades and pins with six pressure slits. He believes those contacts improve grip over traditional bronze, pure copper or phosphor-copper variants. Finally there’s his mysterious MRCT aka midrange control technology. To combat a midrange-centric perspective, Kang Su’s recipe addresses the frequency extremes with a strategic combination of thick gauge (better bass), low capacitance (better treble) and specific plating for a particular impedance (midrange). These then are the core design parameters which he applies to his RCA and XLR interconnects, speaker cables and power cords.