50W Audio Amplifier


50W Audio Amplifier circuit diagram
About the schematic diagram:

The circuit is designed such that most of the components are not critical and can be easily replaced by nearest values.This make it ideal to assemble from your electronics junk box.

The capacitor C1 controls low frequencies and capacitor C2 controls high frequencies.The circuit ia basically a class B amplifier.The transistors 2N 3055 serves the function of driving the speaker.The other transistor functions as pre amplifiers for the driver stage.This is the basic scheme of the circuit.The maximum power level of amplifier can be set by adjusting the 500 Ohm POT connected with the BC107 transistor.


  • The circuit can be powered using a 50 V DC power supply with 5A current rating.Up to 60 v can be given to the circuit.Any way the power supply must be well regulated and filters to avoid noise.
  • Adjust the 500 ohm POT to obtain optimum performance.
  • All capacitors must be rated higher than the supply voltage.
  • Volume control can be attained by connecting a 10 K POT in series to the input of the amplifier.(Not shown in circuit).
source: circuitstoday