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25 Watt MOSFET Audio Amplifier Circuit

This relatively simple schematic is an audio amplifier circuit diagram that uses MOSFET transistors to generate more than 25 Watt output.

Screenshot: 25 Watt MOSFET Audio Amplifier Circuit

This high quality 25 Watt audio amp can be connected directly to CD players, MiniDisc Players, Tuners, Cassette players, etc. without the need for a preamplifier.

The page also features the circuit diagram for an ideal dual-rail power supply, with +33 VDC and -33VDC power outputs.

The main transistors in this audio amplifier circuit are:

  • Q1-Q5 - BC560C 45V 100mA Low noise High gain PNP Transistors
  • Q6 - BD140 80V 1.5A PNP Transistor
  • Q7 - BD139 80V 1.5A NPN Transistor
  • Q8 - IRF530 100V 14A N-Channel Hexfet Transistor
  • Q9 - IRF9530 100V 12A P-Channel Hexfet Transistor
Technical data:
  • Output power: Well in excess of 25 Watt RMS @ 8 Ohm (1KHz sine wave)
  • Sensitivity: 200mV input for 25W output
  • Frequency response: 30Hz to 20KHz -1dB
  • Total harmonic distortion @ 1KHz: 0.1W 0.014%, 1W 0.006%, 10W 0.006%, 20W 0.007%, 25W 0.01%
  • Total harmonic distortion @10KHz: 0.1W 0.024%, 1W 0.016%, 10W 0.02%, 20W 0.045%, 25W 0.07%
  • Unconditionally stable on capacitive loads
Alternate References:
ali9 says: (April 17 2008, 3:41pm)

very useful site

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