• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Electret microphone amp circuit ?

Not open for further replies.


New Member
Looking for a simple electret microphone amp circuit that can drive a 8 ohm speaker and the output be loud enough to hear 5 meter away ?

Ive got these op amp hanging around will they be any good or too weak ?

If the second question is no then please suggest a transistor amp version ?



Well-Known Member
Most Helpful Member
LM386 as the preamp and audio power amp. Download the data sheet to see how to set the gain of the LM386 to the higher gain which will be required to amplify the rather puny output of the electret. You will also have to "bias" the electret to get it to work (which the 386 doesn't do for you).
Last edited:


Well-Known Member
Most Helpful Member
I think you will have acoustic feedback howling because the microphone will hear the speaker and the sound will go around and around.
Turn down the volume control and point the mic and speaker in opposite directions fairly far apart (or in separate rooms) to avoid the feedback.
Then talk loudly very close to the mic.
Not open for further replies.

Latest threads

EE World Online Articles