The Sansui QD-5500 S is a compact quadraphonic receiver designed for four-channel audio output, catering to audiophiles looking to enhance their listening experience with spatial sound features. It integrates various functionalities, allowing users to connect multiple audio sources and enjoy high-fidelity playback. This model includes precise tone controls, an FM tuner, and options for external speakers, enhancing versatility in different audio setups. Its design is typical of the era, featuring a classic aesthetic with analog knobs and a straightforward interface. The power output is adequate for most home environments, making it suitable for a variety of music genres and audio applications. Additionally, the receiver is equipped with outputs for both headphone use and additional speaker connections, ensuring flexibility in how sound is disseminated throughout a space. Specifications include a power output of approximately 30 watts per channel in quad mode, and it supports both 4-channel and 2-channel audio formats. Its build quality reflects a robust construction, characteristic of Sansui products from that time period, ensuring durability and long-term performance.