Based in Foresthill, California, USA, Pass Labs was founded by Mr. Nelson Pass, a well known figure in the high end audio community. Although Pass Labs has only been around for a decade, they have collected more awards than many companies who have been around a lot longer. Mr. Pass is known for unique and innovative, as well as practical, circuit designs. Pass' first designs, in the Aleph line, were single-ended pure Class A solid state. The current Pass Labs "X" series amplifiers use a distortion canceling balanced audio signal circuit, and continue to receive critical acclaim. Today Pass Labs makes amplifiers, preamplifier and speakers.