This is 20W Bridge Audio Amplifier circuit based on the TDA2005 IC, a class B dual audio amplifier, specifically designed for car radio applications etc.
This circuit require Voltage input 18 VDC and will give you Output power - 20 W, 4 Ω
This is the amplifier kit:
This is the schematic:
To get the schematic diagram, component list and component layout, please download this file