Aleph 0

About the Aleph 0

The Pass Labs Aleph 0 is a legendary monoblock power amplifier designed by Nelson Pass and introduced in the early 1990s. It operates in pure Class A mode, delivering 75 watts RMS into 8 ohms with less than 1% total harmonic distortion. The amplifier uses power MOSFET transistors throughout its gain stages, including a differential input stage and cascoded voltage gain stage, biased heavily for exceptional linearity and sonic purity. The chassis is machined entirely from aluminum, anodized and grained for durability and aesthetics, and serves as a large heatsink to dissipate heat generated by the Class A operation. Each amplifier weighs approximately 68 lbs (34 kg) and measures 12 x 12 x 10.5 inches. It features both balanced (XLR) and unbalanced (RCA) inputs, with a gain of 20 dB balanced and 19.9 dB unbalanced. The frequency response extends from DC to 100 kHz (-3 dB), and the output impedance is very low at 0.01 ohms, providing excellent damping factor. The Aleph 0 runs hot, with heatsinks reaching up to 120–130°F during operation, and includes thermal protection to prevent overheating. It is highly regarded for its three-dimensional, finely resolved, fast, and bass-strong sound, combining the advantages of tube and solid-state amplifiers. The amplifier was made in the USA and originally It remains a sought-after vintage amplifier with used prices