Here is a 10W MOSFET audio amplifier circuit, sound that only requires a single source. Single railway material rarely used in power amplifiers class-B. However, for low power applications like this is very thin. Actually I have this circuit a old cassette player is still working and republish as it is. The BD512 and BD522 power MOSFETs is obsolete now and you can use any other power MOSFET game instead of them.
Transistors Q1 and Q2 are connected as a Darlington pair works as a preamp. R3 preset controls the quiescent current, while R2 provides. Output is coupled to the speakers through capacitor C4. Capacitor C5 is the power supply filter and C2 is the input DC decoupling capacitor.
