3W- 5W Audio Amplifier Circuit schematic

The following diagram is the class-a audio amplifier circuit. The circuit capable to deliver about 3W up to 5W power audio output.

Schematic diagram

Parts List:

R1 = 100K - 1/4W R2 = 12K - 1/4W R3 = 47K - 1/4W R4 = 8K2 - 1/4W R5 = 1K5 - 1/4W R6 = 2K7 - 1/4W R7,R9 = 100R - 1/4W R8 = 560R - 1/2W R10 = 1R - 1/2W

P1 = 47K Log. Potentiometer C1,C2 = 10µF/63V C3 = 47µF/25V C4 = 100µF/35V C5 = 150nF C6,C7 = 220µF/25V C8 = 1000µF/25V Q1 = BC560C Q2,Q3 = BD439

Circuit Notes:

• Total electric current drawing of the circuit, recommended measured by inserting the probes of an multimeter across the positive output with the power supply and also the positive rail input with the amplifier, should be 700mA. Adjust R8 to obtain this value if needed.
• Q2 and Q3 must be mounted on a finned heatsink of 120x50x25mm. minimum dimensions.
• If needed, R2 could be modified to get 13V across C8 positive lead and negative ground.
• Add R5 and C5 if the bass-boost facility is needed.

3W- 5W Audio Amplifier circuit source: redcircuits.com