TL071 MOSFET Audio Amplifier general description:
This simple mosfet power audio amplifier circuit, with TL071 and 2 mosfets (IRF9530, IRF530) power amplifiers can deliver up to 45W on 8 ohm. This schematic is based on Siliconix application and is based on variations of voltage on the 2 resistors serial inserted on the voltage supplier of the operational amplifier driver. The mosfet transistors must be mounted on a heatsink at least 1K/W. Amplifier efficiency is 70%, distortions at cut frequency were at most 0.2% at 20Hz on 8 ohm and 10W. With a power supply of +/- 30V the mosfet audio amplifier can deliver 45W on 8 ohm and 70w on 4 ohm. Remember that this audio amplifier is not protected on short circuits so every time you switch on check to see if the speaker is connected.