Mini-MosFet Audio Amplifier


Posted on Feb 7, 2014

R1_2K2 1/4W Resistor R2_27K 1/4W Resistor R3, R4_2K2 1/2W Trimmers Cermet or Carbon (or 2K) R5_100R 1/4W Resistor R6_1K 1/4W Resistor R7, R8_330R 1/4W Resistors C1_22 µF 25V Electrolytic Capacitor C2_47pF 63V Polystyrene or Ceramic Capacitor C3, C4_100 µF 50V Electrolytic Capacitors C5_2200 µF 50V Electrolytic Capacitor Q1_BC550C 45V 100mA Low noise


Mini-MosFet Audio Amplifier
Click here to download the full size of the above Circuit.

High gain NPN Transistor Q2_IRF530 100V 14A N-Channel Hexfet Transistor (or MTP12N10) Q3_IRF9530 100V 12A P-Channel Hexfet Transistor (or MTP12P10) This project was a sort of challenge: designing an audio amplifier capable of delivering a decent output power with a minimum parts count, without sacrificing quality. The Power Amplifier section employs only three transistors and a handful of resistors and capacitors in a shunt feedback configuration but can deliver more than 18W into 8 Ohm with <0. 08% THD @ 1KHz at the onset of clipping (0. 04% @ 1W 1KHz and 0. 02% @ 1W 10KHz) and up to 30W into a 4 Ohm load. To obtain such a performance and to ensure overall stability of this very simple circuitry, a suitable regulated dc power supply is mandatory. This is not a snag because it also helps in keeping noise and hum of the preamp to very low levels and guarantees a predictable output power into different load impedances. Finally, as the amplifier requires only a single rail supply, a very good dc voltage regulator capable of supplying more than 2 Amps @ 40V can be implemented with a few parts also. Switch off the supply, disconnect the Multimeter and reconnect it, set to measure at least 1Amp fsd, in series to the positive supply (the possible use of a second Multimeter in this place will be very welcomed). Those lucky enough to reach an oscilloscope and a 1KHz sine wave generator, can drive the amplifier to the maximum output...




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Ultrasonic Bat reciever
    Crystal oscillator
    Switching Supply In Telephone Ring Generator
    drm down converter for 455khz if
    lantern dimmer flasher circuit diagram
    Infrared Remote Control Tester
    Unipolar Stepper Motor Controller Circuit
    Yaesu G-400 Antenna Rotator Controller
    Free Energy Schematic
    100W + 100W power amplifier



    Top