This is 2 x 3W stereo audio amplifier based on IC power BA5406. This circuit which will give you 3W power in each channel. This circuit will be great for indoor audio system.
R1, R2 = 120 ohm R3, R4 = 2R2 ohm C1, C2, C11, C12 = 220nF nonpolar capacitor C3, C4, C5, C6, C7, C8 = 47uF/16V electrolytic capacitor C9, C10 = 470uF/16V electrolytic capacitor IC = BA5406
The BA5406 contains two sets of AF power amplifiers. It delivers 5W x 2 into 3 ohm loads with a 12V supply. The BA5406 has good low-voltage characteristics, and the “pop” sound when power is applied is small. It generates little radio-band noise, minimal RF radiation.
Recommended supply voltage: 5-15V max. Typical 12V. Ideally the power supply should be able to deliver over 2.5Amps. This means that a typical “cheap” plugin power supply (wall wart) will not be good enough. The power supply leads should be as short as possible. Quiescent current 20-70mA, typically 40mA.
Download the manual of 2x3W Audio Amplifier with IC BA5406 in PDF version:
Download the BA5406 datasheet: