Perfect-Surface Copper+ has an astonishingly smooth and pure surface. Proprietary metal-processing technology protects the wire’s surface at every stage of drawing and fabrication. When high-purity low-oxide copper is kept as soft, pure and smooth as possible, it becomes a wonderfully low-distortion PSC+ conductor. PSC+ is manufactured by applying the same exceptional technology to an ultra-pure copper. The resulting sound quality is even more focused and simply less in the way. For over 30 years AudioQuest has pioneered the use of superior metals; yet even we were surprised by the huge leap in performance made possible with Perfect-Surface Technology. PSC+ simply outperforms all previously available copper metals at any price. All of Big Sur's conductors are solid. Electrical and magnetic interaction between strands in a conventional cable is the greatest source of distortion, often causing a somewhat dirty, harsh sound. Solid conductors are fundamental toward achieving Big Sur’s very clean sound.