Pass Labs
Pass Labs is an American high-end audio brand based in Auburn, California, founded in 1991 by designer Nelson Pass. Building on experience gained at Threshold Audio, Pass set out to create amplifiers that were simple, distortion-free and musically honest — a philosophy that still defines the brand today.
Origins
The company began in Nelson Pass’s home workshop with the Aleph 0, a single-ended Class A monoblock that quickly earned a reputation among audiophiles for its effortless, natural sound. As demand grew, production moved to a dedicated facility in Auburn, where every product is still hand-built.
SuperSymmetry™
In 1998, Pass Labs introduced SuperSymmetry™, a patented circuit topology that cancels distortion at its source rather than correcting it afterwards. This innovation became the foundation for the brand’s X and XA series, and remains central to its designs to this day.
Philosophy
Pass Labs favours pure Class A and high-bias Class A/B circuits over complex digital correction. The result is a sound that’s warm, textured and unmistakably analogue — power and control without harshness or fatigue.
Today
More than three decades on, Pass Labs remains one of the most respected names in solid-state amplification, with a range spanning power amplifiers, preamplifiers, integrated amplifiers and headphone amplifiers, all engineered and assembled in California.
