Audio Amplifier Design (CE Amplifier - Class AB Power Amplifier)


Joined Dec 11, 2013
in the coupling stages you dont need 470uF insted of lesser values such as 4u7 or 2u2. check the dc bias of driver side. for how much power the amp is designed for?


Joined Nov 30, 2010
The 2N3906 is wrong way up.
You can't send a whole amp through these tiny transistors.
There is too much current in R2 compared to R3. You are running out of voltage at R3.


Joined Apr 4, 2016
As has been said, you need feedback from the output back to the input stage to set the overall gain of the amplifier.
Carefully designed, this feedback also sets the DC operating point and reduces distortion.

For a simple design with descriptions of the operation, have a look at this.


Joined Aug 1, 2013
Since your intent is limited forward gain with no overall negative feedback, delete C5. It is the cause of the clipping. At audio frequencies, Q2 is trying to provide infinite gain.

If the output transistors heat up with no signal, change D1 and D2 to 1N914 / 1N4148. The lower forward voltage drop will decrease the static current through the output stage.