This is a schematic of a 10W stereo audio amplifier using TDA2009A  amplifier IC. TDA2009A is a good IC provides quality sound. It has built  in features like output current protection and thermal protection etc.  The circuit can be operate between 8 to 24V DC with 1 to 2 amphere.
10W Stereo Audio Amplifier Circuit Diagram :
 
 
10W Stereo Audio Amplifier Circuit Diagram :
 
 
If  you want to operate this 10 watt amplifier circuit with watt amplifier  circuit with mains supply then use a filtered and stable power supply to  reduce mains hum. 10 watt out put power can be obtained by providing  20V 1.5A to the circuit. Use good and thick heatsink with the IC. 
 

 
 
 
