Try to make a power amplifier with a filter

112

01:36:49

           My friend and I try to make this circuit on a breadboard. I would like to know how to choose proper opamps and also both push and pull transistor. We do need your help.

published 6 years ago

westelaudio

6 years ago

Use an op amp with low impedance load capability. For transistors, just try... Class B is not recommended for audio though.

westelaudio

6 years ago

Although, with negative feedback and a fast op amp, it might sound alright.

hurz

6 years ago

With 5V supply @8Ohm you can get 1.5Watt maximum. Not much for a "power amplifier". The feedback network does not need so low in impedance, it just matters its ratio. So if you make it with 300/20 Ohm you can do it with a factor hundred higher 30k/2k and you get the same effect. For frequency compensation you then just need pico farads. OpAmps directly coupled to a push pull stage cause many new problems. Better you bais the push pull stage proper and dont have the voltage jumps around zero volt.

westelaudio

6 years ago

@hurz the concept itself works, i think ICs like the TDA2004 work on this concept, Class B with negative feedback

westelaudio

6 years ago

http://www.circuitstoday.com/15w-class-b-audio-amplifier

westelaudio

6 years ago

Maybe try this.

westelaudio

6 years ago

http://everycircuit.com/circuit/6615671786700800

KeenZa

6 years ago

@hurz @westelaudio Thank you very much. I will try all of that.

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