The Marantz SD-50 is a cassette deck that features a dual-capstan design, which helps to provide consistent tape travel and improved sound quality. It offers a variety of playback options, including Dolby B and C noise reduction, enhancing audio fidelity by reducing tape hiss. The SD-50 is equipped with various features such as an auto-reverse function, allowing for uninterrupted playback of both sides of a cassette without manual intervention. Additionally, it typically includes level meters for monitoring playback levels, ensuring optimal audio output.