35W Audio Amplifier based LM391

35W Audio Amplifier based LM391
This is the circuit diagram of a 35W audio amplifier based on LM391. The LM391 is a comprehensive driver to the power transistors. It needs only few external components to work. With the TR1 we can adjust the bias current to 45mA. Inductor L1 consists of 20 turns of wire thickness of 0.9mm, around the resistor R16. The transistors Q3-4 must be placed onto a heatsinks. If you use the Q3-4 with type of TIPxxxx, you can be placed