The Yamaha KX-390 is a cassette deck that was part of Yamaha's series of audio equipment. It features dual-capstan design for improved tape motion stability, ensuring high-quality sound reproduction. The device has Dolby B and Dolby C noise reduction systems, which help to minimize tape hiss and enhance overall audio clarity. The KX-390 is equipped with an auto-reverse function, allowing for playback of both sides of the tape without manual intervention. It also has a range of connectivity options, including RCA outputs, to facilitate integration into various audio systems. This model is noted for its reliability and robust build quality, making it suitable for both casual listening and more critical audio applications.