On the wish list of many hobbyists at the top probably is an audio amplifier. With the currently available IC's is also easily achievable. There are also links to circuitry in conventional (MOSFET / bipolar) technology

Here you will find Schematic Circuit Diagram for DIY and further information on HIFI Audio Amplifier
Sponsored Ads:

A wonderful Kopfhoererverstaerker in Roehrentechnik. Unrestricted recommended!	www.headwize.com/projects/showfile.php?file=cmoy5_prj.htm
25 Watt MOSFET Amplifier	www.redcircuits.com/Page2.htm
Compact module with 50W, board available	sound.westhost.com/project19.htm