Push-pull audio amplifier design

Thread Starter


Joined May 9, 2023
Please look at the datasheet of the low power 2N3904 output transistor you are using.
Why are you overloading the 2N3904 output transistor? Its absolute maximum output current is only 200mA and it works poorly above 100mA. The datasheet shows that its beta can be as low as 30 at Ic of 100mA.

For 2W in an 8 ohms speaker you need 4VRMS across it which is +5.6V peak (+700mA) and -5.6V peak (-700mA).
Select a transistor that works well at 700mA but not as an emitter follower. Use a push-pull pair of transistors.
DO Not put DC current in a speaker. Use a coupling capacitor.
I have a similar problem as the asker here. When using a push-pull pair of transistors. For example I tried using Class AB what should I check when trying to implement this is there any sort of advice on what I should look out for?

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