Andros PS-1

About the Andros PS-1

The Zesto Audio Andros PS-1 is a vacuum tube phono preamplifier designed for both moving magnet (MM) and moving coil (MC) cartridges. It features a dual mono design housed in a robust steel chassis, with separate inputs and outputs for each channel. The preamplifier uses ECC83S/JJ Electronic tubes and offers 45dB gain for MM and 65dB gain for MC cartridges. It provides adjustable loading for MC cartridges with eight selectable resistance settings (20, 30, 40, 50, 100, 200, 400, and 1000 ohms) accessible on the rear panel, allowing on-the-fly adjustments without opening the chassis. The RIAA equalization is implemented with interstage passive de-emphasis, maintaining accuracy within ±0.5dB, with lab measurements showing even better performance (±0.2dB). Noise levels are very low at -75dBu, and the unit offers excellent crosstalk and overload margins. The outputs are single-ended RCA, and the unit includes features such as cartridge load selection, sensitivity selection for MC, and grounding/floating switches. The Andros PS-1 is praised for its sonically neutral, transparent, and musically natural sound, with a smooth, harmonically rich, and dimensional presentation. It weighs approximately 9 kg and measures 432 x 305 x 127 mm. The unit is hand-built in the USA and It remains a highly regarded phono preamplifier for audiophiles seeking a tube-based solution with extensive flexibility and excellent sound quality.