See STK4231II and build a 2 channel OCL 100W stereo audio amplifier circuit with PCB layout. It's easy, small without adjusting, and cheap.
This is a small Stereo amplifier 3W + 3W using BA5406-IC. It use 12V power supply as source of this project. and use a few part so easy to build.
This is 2 watts + 2 watts Stereo small LM386 amplifier x3 ICs. It is cheap and easy to builds for BCL amplifier,mobile,MP3 player using 6V battery (AA x 4) [...]
Suitable for beginners thought will build the electroacoustics to listen yourself.
The Super Small and mini Power Amplifier BCL 1.2W by TDA7052 as Low voltage amplifier circuit 1.5V up to 15V, tiny size and can adjust volume by VR1 [...]