The Sony TC-K15 is an obsolete audio cassette deck and tape recorder released by Sony Corporation in the late 1980s. It features a Dolby-B noise reduction system, a detachable power cord, and the ability to record and play back standard audio cassettes. It also has a built-in Dolby-C decoder, allowing it to play back cassettes recorded with the more advanced Dolby-C noise reduction system. However, because of advancements in technology and the rise of digital formats, the Sony TC-K15 is no longer commonly used and has become largely outdated.