The filter circuit of this main circuit will sent to through to the signal that middle frequency. At the same time is attenuated the others frequency into input signal to…
This is a 4 transistor audio amplifier circuit. Which is a 4-transistors complementary push-pull amplifier, that shows the basics of audio amplifier design.
This is three Simple 50w OTL audio amplifier circuit by 2N3055, can build easy and cheap, It's durable and very loud sound , Not needed speaker Protection. [...]