Audio Amplifiers

Sort of a basic electronics project. Lots written on the subject. Plus if I get decent at it, I can build speakers, which are always fun.

http://www.rdimitrov.info/blog/show.php?entry=Microcontroller%20Class%20D%20Amplifier

There are also some IC's that do analog to pwm (or voltage to pwm). That would be a good base for a class d amp.

There are some 555 amps, that could be fun: http://www.circuitdiagram.org/555-audio-amplifier.html