• Register
  • Login
  • This simple power mosfet audio amplifier circuit, with TL071C and 2 MOSFETs (IRF9530 and IRF530) can deliver up to 45 Watts on 8 Ω speaker. This schematic is based on Siliconix application and on variations of voltage on the 2 resistors that are serial inserted on the voltage supplier of the operational amplifier driver. The MosFet transistor must be mounted on a heatsink with at least 1K/W.

    Amplifier’s efficiency is 70%, distortions at cut frequency were at most 0.2% at 20Hz on 8 Ω and 10W. With a power supply of ± 30V the mosfet audio amplifier can deliver 45W on 8 Ω and 70w on 4 Ω. Remember that this audio amplifier is not protected on shortcircuits so everytime you switch on check to see if the speaker is connected.

    Mosfet amplifier circuit schematic

    70 watt mosfet audio amplifier schematic

    
    subscribe to newsletter

    5 Responses to "70 Watt MOSFET Audio Amplifier"

    1. want to get product updates on my mail if possible

    2. love this site and yawn for more

    3. baretter says: on August 6, 2013 at 5:05 pm

      only for subwoofer. Too many intermodulation in high frequency

    4. NUSSLER NUSSLER says: on April 24, 2014 at 3:03 am

      Works just fine!
      No need to modify.

    What do you think about this article? Leave a comment!

    You may add a picture too (related to electronics)