50W Audio Power Amplifier based ICL8063

This is the 50W audio power amplifier for general purpose application. The circuit is based ICL8063 and 2N3055/2N3791 power transistor . The amplifier has an input for a radio, TV, stereo or other line level devices. It also has a phono input for a record player, guitar, microphone or other un-amplified source. With the addition of a low pass filter at the input, it makes a great amplifier for a small subwoofer.

The power supply is already designed on above schematic diagram. It is a splitted / dual polarity power supply. Maintain the power supply output at +35V / 0 / -35V since the supply recommendation for ICL8063 is 35V.


ICL8063 is a unique monolithic power transistor driver amplifier that allows construction minimum chip power amplifier systems. includes built safe operating area circuitry, short circuit protection voltage regulators, primarily intended for driving complementary output stages

Parts List:
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 Meg (5%) 1/2 W Resistor
R8,R9 ................. 0.4 Ohm 5 W Resistor
R11 ..................... 10K Pot
R12,R13 ............. 51K 1/4 W Resistor
R14 ..................... 47K 1/4 W Resistor
C1 ....................... 100uF 35V 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 ............. 10,000uF 50V Electrolytic Capacitor
U1,U2 ................. 741 Op Amp
U3 ....................... ICL8063 Audio Amp Transister Driver thingy
Q1 ....................... 2N3055 NPN Power Transistor
Q2 ....................... 2N3791 PNP Power Transistor
BR1 .................... 250 V 6 Amp Bridge Rectifier
T1 ....................... 50V Center Tapped 5 Amp Transformer
S1 ....................... SPST 3 Amp Switch
S2 ....................... DPDT Switch
F1 ....................... 2 Amp Fuse
SPKR1 ................ 8 Ohm 50W Speaker
MISC ................... Case, Knobs, Line Cord, Binding Posts Or Phono Plugs (For Input And Output), Heatsinks For Q1 And Q2

50W Audio Power Amplifier based ICL8063 and 2N3055/2N3791