Does anyone know of a good amplifier circuit using an electret condenser microphone as input? The output should be loud enough to feed into an earphone. I try this **broken link removed** which works but the output volume is very soft. I need to tap on the microphone or blow into it in order to hear the noises in the headset. I remember I came across a similar amplifier circuit that uses 3-4 transistors which was very sensitive. I built it and could hear every single noise inside my room. But I can't seem to find it now.
I adjusted the value of R2 and R3 in the existing circuit and could see some improvements, but the output volume is still not loud enough. I also tried to add one more amplifier stage using another transistor but the result is a high pitch tone in the output (some unstable oscillation I guess).
Thanks for any advice.
I adjusted the value of R2 and R3 in the existing circuit and could see some improvements, but the output volume is still not loud enough. I also tried to add one more amplifier stage using another transistor but the result is a high pitch tone in the output (some unstable oscillation I guess).
Thanks for any advice.
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