The Above circuits are based on TEA2025 is a monolithic integrated audio amplifier in a 16-pin plastic dual in line package manufactured by UTC .Circuit has an Internal Thermal Protector. It is designed for portable cassette players and radios. You can also use it as your PC Audio Amplifier. A few external components required to build this circuit.
Use 9v transformer to play the circuit. But not more than DC12v. Because it can damage the amplifier IC.
Stereo per channel
Supply Voltage min = DC3v @ 500mA
Supply Voltage max = DC12v @ 500mA
Supply Voltage recommended = DC9v @500mA