The Sony TC-K661S is a cassette deck that was part of Sony's lineup during the 1980s. It features a dual-capstan configuration, which helps to improve tape stability and playback quality. The device supports both normal and chrome tapes, allowing users to play back a variety of cassette types. The TC-K661S is equipped with a range of features including auto-reverse capability, allowing uninterrupted playback of both sides of a cassette. It features a digital tape counter for easy tracking of playback positions. The deck also includes a record level meter for precise audio monitoring during recording. Additionally, it is designed with Dolby B and C noise reduction systems, which help to reduce unwanted tape hiss and improve overall sound clarity. The aesthetic design of the unit includes metal front panels and a stylish layout, typical of the era’s audio equipment.