In order to listen to music directly from a portable mp3 player or to amplify the
audio signal of my pc, I built this simple amplifier made exclusively from used
parts from the e-waste. Even though very simple, an acceptable sound quality can be
achieved. The power transistor 8210 needs to be connected to a heat sink.
Potentiometers allow the adjustment of the transistors’ optimal operating points. If
you use an unstabilized power supply, the 1000 µF capacitor minimizes AC hum.