This is 120W power amplifier schematic using TO-3 package complementary transistors, NPN and PNP polarity. The well-known power transistor pair of 2N3055 and MJ2955 used in this circuit. +/- 50V symmetrical (split/dual polarity) power supply with minimum 3A electric current should be used for maximum performance.
Transistors
Capacitors
Resistors
Diodes
Others
Bottom PCB Layout (Copper)
Top PCB Layout and Component Placement
How to mount the transistors to the aluminium heatsink, see below image:
The points are: prevent circuit shortage, use proper isolator and use thermal compound for maximum heat spreading to the heatsink. Use mica between the transistor and the heatsink.
Power Supply Bottom PCB Layout
Power Supply Top PCB Design
This is how to connect the amplifier module to the speaker, power supply and audio input. And connect the power supply module to the transformer.
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How can I get the Gerber files for this project?
thank you
Is there schematic for the power supply and where to place the 3A fuse?
The PCB design shows two wires connection to GND from Top are they jumper wires or fuse connection?
Can I use 1N5408 instead on 1N5404 diode?
Dear Sir, I am interested in your 120 watt Audio Amplifier DIY above, in the schematic it shows 50v DC power supply, but in the instruction it require 35v dual supply, which one to use?
Can I replace the power, supply with ready made switching power supply of 35v not dual only plus and minus out put, no earth connection the reason I cant find transformer with 35v dual power supply, or too expensive and too heavy.
Thank you.
Your reply and help is very much appreciated.
I have build that circuit and its 100% working thanks alot....very smart and useful. Please send a circuit diagram 200 watts using MOSFETs
where to use 20k potentiometer your circuit
potentiometer of 20K if you want to add volume control
Read more http://circuitdiagram.net/120w-power-amplifier-power-supply.html
I am interested in 120watt amplifier, I want to assemble this circuit. I hope that I can manage it.
120W Power Amplifier pcb