Founded in 1991 by legendary audio designer Nelson Pass, Pass Laboratories, Inc. markets its unique amplifiers, preamplifiers and speakers throughout the world. The company has been based in Foresthill, California, since its beginning, and is widely regarded as one of the most innovative audio brands in the world.
Our critically acclaimed Aleph, X and XA-Series products have won numerous awards, and Founder Nelson Pass holds numerous audio patents. His achievements include developing the first dynamically biased Class A amplifier circuit, developing a fully cascode audio power amplifier, and developing the Stasis amplifier in 1977.
He helped popularize solid-state, single-ended Class A power amplifiers, and developed the very successful Aleph series of products, and the Super-Symmetry™ circuit, which achieves exceptionally low distortion and noise levels. The company is now poised to introduce a new generation of amplifiers and other high-performance audio products.
The XP-20 Pre-Amplifier