90 W audio power amplifier based on transistor

Using only four transistors in the quasi-complementary amplifier configuration, this transistor power amplifier circuit can deliver 90W of power into 4 ohm loads and at low cost.

As shown in the transistor power amplifier circuit there are no expensive components in this circuit, except the power transformers and speakers. As shown in the diagram there are no expensive components in this circuit, except the power transformers and speakers. Input stage is formed by this two current driver directly raised a pair of transistors of the output stage. Transistor level end (2N3055) mounted on a heat sink to keep the lifetime of these devices. Supported by one source (of 80Vcc) at the output of the final stage, before the speaker, a capacitor is placed to block DC current, and just skip the audio signal. The power supply circuit 90 W audio power amplifier must be sufficient to provide current 1.5A per channel audio. Thus the power required to operate the stereo 3A and 6A is required for the four audio channels.

90 W audio power amplifier parts list :
Resistors : 2.2K (2), 47 ohm (3), 470 ohm, 100 ohm, 15 ohm, 0.33 ohm (4)
Capacitors : 1uF, 4700uF
Diodes : 1N4001 (2)
Transistors : 2N3904, 2N3906, 2N3055(4)