This mp3 player is a project for ELEC3404, made from few transistors, capacitors, diodes and resistors. Basically, it requires a +15V voltage from the red wire, a -15V voltage from the white wire, a ground connection at the green wire, and it takes a music input signal(e.g. mp3) from the purple wire and amplifies to an output signal through the orange wire which will be connected to a speaker.

A huge heat sink for the TIP31 and TIP32 transistors.