Prologue: This legendary Sansui AU-20000 (Japan Domestic Market model at 100V) has been carefully restored in Japan by takumi craftsmen—former Sansui technicians who understand not only how the amplifier works, but why it was made this way. Each component is examined, adjusted, and returned to harmony, preserving the original voice and balance envisioned by Sansui.
Nothing is rushed. Nothing is excessive.
This entire restoration work takes two to three months, allowing the amplifier to settle naturally, as it should. What remains is not merely an amplifier, but a piece of Japanese monozukuri—quiet, enduring, and made to be lived with. It will reward its owner with many unhurried hours of listening, where music is allowed to breathe.
Background:
The AU-20000 is Sansui’s finest integrated amplifier from Professional Series during their golden era of manufacturing and some would argue the best integrated Sansui ever produced (and the most powerful).
It is a high-performance integrated stereo amplifier known for its exceptional build quality and power output. It delivers a continuous 170 watts per channel into 8 ohms, with less than 0.05% total harmonic distortion, ensuring clean, distortion-free audio even at high output levels.
This amplifier is constructed with premium components throughout, including durable switches, potentiometers, high-quality filter capacitors, and output devices.
It also features a high-performance MM (Moving Magnet) phono preamp, a headphone amplifier, tape circuits, tone controls, and muting functions for versatility. One standout feature is its gorgeous moving coil power meters, adding both functionality and a visual touch of elegance.
Overall, the Sansui AU-20000 is a statement piece that embodies the peak of 1970s Japanese HiFi engineering. With its outstanding build quality, powerful performance, and added features, it's one of the ‘holy grail’ of Sansui’s amplifier in vintage HiFi circles.
Sansui AU-20000 Professional Series
The Sansui AU-20000 is a pre-main amplifier is a high-power unit built to deliver robust performance along with specialized features for dedicated audiophiles. It utilizes an all-stage direct connection pure supplementary OCL (Output Capacitor-Less) system with triple push-pull output stages, allowing for powerful output while keeping distortion low.
The amplifier includes a CR+NF equalizer with dual amplifier configurations for precise sound reproduction, as well as triple tone control for adjusting bass, midrange, and treble. For those who prefer an unaltered sound, the tone defeat option provides a flat response.
A standout feature is its large power supply unit equipped with a high-performance toroidal transformer and a stabilized circuit, ensuring consistent power and stability even during dynamic peaks. Additionally, it offers switchable input sensitivity and impedance settings, allowing compatibility with a variety of sources and equipment setups.
For protection, the AU-20000 incorporates triple protection circuits, which safeguard against over-temperature, DC asymmetry, and conditions outside the safe operating area (ASO), ensuring long-term reliability and safety.
The amplifier utilizes high-speed class AB amplifiers with bipolar output devices, a common design architecture from the era, delivering both efficiency and powerful performance. Though the phono preamp lacks MC (Moving Coil) capability, this can be easily remedied by adding a high-quality step-up transformer to the setup.