Pass Labs

[1] Pass Labs makes amplifiers, preamplifier and speakers.

[2] The Pass labs Aleph series of amplifiers operated pure class A and contained internal circuitry using MOSFETs.

After the Aleph series of amplifiers was discontinued, a separate entity Volksamp was licensed to continue to produce a similar product.

[3][4] These current domain amplifiers are only suitable for use with certain types of speakers.

[5] Current Pass Labs "X" series amplifiers use a distortion canceling balanced audio signal circuit.