Circuit Description

The circuit diagram given below is 50 W transistor amplifier. This circuit is a class-B amplifier. In this circuit, seven transistors are used. Out of these transistors, six transistors acts as preamplifiers and the rest one is for driving the speaker. The transistor 2N 3055 is used here to drive the speaker. The 500 ohm pot connected to BC 107 transistor is used for adjusting maximum power level of the amplifier.

In audio applications always use power amplifiers. This circuit is a very rugged and reasonably power amplifier. The capacitors C1 (220 uF) and C2 (100-200 uF) is for controlling low and high frequencies respectively. 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. This amplifier can produce 60W rms at 50V supply on an 8 Ohm load.

Circuit Diagram

50 Watt Transistor Amplifier Circuit

50 Watt Transistor Amplifier Circuit


  • The circuit is designed such that most of the components are not critical and can be easily replaced by nearest values
  • This circuit is ideal to assemble from your electronics junk box
  • Volume control can be added to the circuit¬†by connecting a 10 K POT in series to the input of the amplifier.