The amplifier circuit explained here was built and tested by me and am extremely pleased by its performance and also ruggedness as far as maintenance and handling is concerned.
Basically, the entire configuration is a symmetrical class A amplifier incorporating an input filter stage, an intermediate driver stage and a powerful symmetrical output stage consisting of the versatile 2N3055 power transistors. The circuit efficiently drives a 100 watt 4 Ohms speaker with inputs derived from any audio source like a cell phone or DVD player etc.
Before you learn how to build this interesting and useful 100 watt amplifier circuit using 2N3055 transistors, a prior understanding of the involved circuit configuration would be very handy, let’s begin the explanation with the following points:
Power Supply Circuit
The power supply circuit is also shown along side and as can be seen there’s nothing special about it and may be built using the shown ordinary sets of components.
Parts List of 100 watt amplifier circuit
General Purpose PCB,
All the transistors T10, T13, T11 and T14 ae mounted on suitable heatsinks
The original design, (courtesy - elektor electronics)