electret michi 00,
What type of microphone are you using.?
E
could you please tell me how to do that?I don't see any biasing network for the output transistor.
A quick look at the transistor specs leads me to think that the 3904 is probably okay to use, though the 3403 appears to have significantly higher gain at lower currents. That is possibly causing more base current in Q1 than the biasing network can support.