The Pioneer SX-403 RDS is a stereo receiver that features an integrated amplifier and a built-in FM/AM tuner. It is designed for home audio systems and includes RDS (Radio Data System) functionality, which allows users to receive additional information from FM broadcasts such as station identification and song title. The SX-403 typically offers multiple audio inputs for connecting various components, including CD players and turntables. Additionally, it often includes tone controls, speaker outputs, and headphone jacks to enhance the listening experience. The receiver is known for its blend of functionality, performance, and user-friendly interface.