50 watt amplifier circuit diagram

This is a general purpose 50 watt audio amplifier that can be easily built. The amplifier can be used to amplify the output of a radio, TV, stereo, or other audio device. It can also be a final amplifier for a record player, guitar, microphone, or other unamplified signal source. With the addition of a low pass filter on the input, it becomes a nice little subwoofer amplifier.

Circuit components

R1 200 ohm 1/4 W resistor

R2 200K 1/4 W resistor

R3 30K 1/4 W resistor

R5 1K 1/4 W resistor

R6 5K 1/4 W resistor

R7, R10 1 megohm (5%) 1/2 W resistors

R8, R9 0.4 ohm 5 W resistors

R11 10K potentiometer

R12, R13 51K 1/4 W resistor

R14 47K 1/4 W resistor

C1 35V 100uF electrolytic capacitor

C2 0.011uF capacitor

C3 3750pF capacitor

C4, C6 1000pF capacitor

C5, C7, C8 0.001UF capacitor

C9 50PF capacitor

C10 0.3uF capacitor

C11, C12 10,000 UF 50V electrolytic capacitor

U1, U2 741 operational amplifier

U3 ICL8063 Audio Amplifier

Q1 2N3055 NPN power transistor

Q2 2N3791 PNP power transistor

notes

1 I know I skipped R4. That's not a problem :-)

2 100HZ input distortion is less than 0.1%, 20kHz input increases to about 1%.

3 I have not been able to find a suitable T1 (transformer). You can use two 24V 5A units in series.

4 Q1 and Q2 will require heat sinks.

5. Find U3 (ICL8063 Audio Amplifier IC), you may have trouble finding it because it is discontinued.