The circuit shown here is of a simple and easy Class-B audio amplifier based on opamp TL082, transistors TIP141 and TIP142. LM833 will be twin opamp with high slew rate and low distortion significantly designed for audio applications. This audio amplifier circuit will deliver 15 watt audio output into an 8 ohm speaker at +12/-12V DC twin supply.
Both opamps within the IC are used here. IC1a is wired as a buffer and capacitor C3 will the task of input DC decoupling. Ic1b is wired within the inverting mode and it provides negative feedback. Complementary power transistors TIP41 and TIP42 are wired within the class B push pull schematic and that they drives the loud speaker. Diode D1 provides 0.7V bias voltage for the push pull combine and capacitor C2 protects the 0.7V bias voltage across D1 from serious voltage swings at the IC1b’s output.
Notes :
- The audio amplifier circuit must be assembled on a good quality PCB.
- Use a holder for mounting IC1.
- Use a +12/-12V dual supply for powering the amplifier.
- Potentiometer R2 can be used as a volume control.
- Raising the power supply voltage will increase the output power. Anyway note the following points.
- TIP42 and 41 can handle only up to 6A.
- Maximum supply voltage IC1 can handle is +16/-16 V DC.
