Here we learn how to make a very simple 100 watt amplifier circuit using a 2N3055 transistors and a few other passive components.
Simply by incorporating just four transistors in the quasi-complementary configuration this 2N3055 simple power amplifier circuit can deliver a good 100 watts of power over an attached 4 ohms loud speaker, and the entire design can be built at a really low cost (to be precise it would cost you only 1/2$ per transistor).
As exhibited in the above diagram you won’t find no costly or obsolete hard to find components in this amplifier circuit, except the power supply transformer and possibly the 4 ohm loud speaker.
The input stage is created by configuring a couple of current drivers transistor stages responsible for triggering the pairs of power BJTs positioned at the output stage.
The 2N3055 power stage at the output should be mounted on large heat sinks to ensure that this crucial stage is able to dissipate adequately and function with optimal efficiency.
The a power supply of 80V, it becomes necessary to put a series capacitor in between the output stage and the speaker in order to block the DC supply from entering the speaker and allowing only the amplified 100 watt music power.
For a mono 100 watt amplifier the power supply could be rated at 1.5A , for stereo this needs to be doubled at 3 amps, and in case a quadraphonic amplifier is required then make sure to use transformer rated to handle a minimum of 6 amp.
The following diagram shows the pinout details of the various transistors used in this simple 100 watt amplifier circuit using 2N3055 transistors