Aleph Ono

About the Aleph Ono

The Pass Labs Aleph Ono is a solid-state phono preamplifier for moving-magnet and moving-coil cartridges. Its three-stage circuit uses a low-noise, non-inverting MC pre-preamplifier, a main gain stage providing MM gain and RIAA equalization, and a third unity-gain inverting stage for balanced output. The circuit employs matched low-noise JFETs and power MOSFETs, with no loop negative feedback in the single-ended signal path. It provides 40 dB of MM gain and up to 71 dB of MC gain, with 76 dB available through the balanced output configuration. Cartridge loading is adjustable from 47 kΩ with selectable capacitance for MM operation and from 5 Ω to 47 kΩ for MC operation. RIAA accuracy is specified at ±0.1 dB from 20 Hz to 20 kHz. The Aleph Ono offers balanced and single-ended outputs, a maximum output of 20 V RMS, less than 0.05% THD at 20 V, and a 150-ohm output impedance per channel. It measures 19 inches wide by 4 inches high by 11.5 inches deep and weighs 35 pounds.