TDA2003 is a cheap amplifier that is designed to run on single rail power supplies (unipolar). It provides a high output current capability (up to 3.5A), very low harmonic and cross-over distortion.
TDA2003 10W car radio audio amplifier
TDA2003 18W bridged audio amplifier
TDA2003 can be used as an BCL (bridged amplifier) and car deliver up to 18W.