This is a simple audio pre-amplifier circuit using single transistor 2N3904.

Simple Audio Pre-Amplifier

This easy circuit provides good gain to weak audio signals such as electret microphone. Use it in front of an RF oscillator to make an RF transmitter that’s very sensitive to sound. Power supply used for this circuit is wide range from 3VDC to 9VDC, you may choice the middle range about 6VDC to minimize the risk, safety purpose

Components List:

R1 = 10kR2 = 100kR3 = 10kC1 = 0.1?f or if you prefer 104 or 100nC2 = 0.1?f or if you prefer 104 or 100nQ1 = 2N3904MIC1 = a common electret microphone

Add comment


Service manuals

Copyright © 2020 Electrical circuits.