The Sansui AU-666 is a solid-state integrated amplifier that was produced in the early 1970s. It features a classic design with a warm and richly detailed sound quality that many enthusiasts appreciate. The amplifier is equipped with a dual power supply and utilizes a push-pull output stage for improved performance. It is capable of delivering a power output of 60 watts per channel into an 8-ohm load, making it suitable for a variety of speaker configurations. The AU-666 includes various inputs, including phono, tape, and auxiliary, along with a built-in equalizer for sound shaping. Other notable features include a loudness control, tone controls for bass and treble, and separate volume controls for left and right channels. The unit is designed to accommodate both low- and high-impedance speakers, and its robust build quality contributes to its durability. Many users value the AU-666 for its ability to reproduce music with a dynamic range and presence that enhances listening experiences across different genres of music.