This simple circuit will allow you to convert an electret mic signal into a dynamic mic signal. This is usefull when you need to plug a computer microphone into a stereo or mixer. Since electret microphones require power, this circuit supplies power to the microphone and amplifies the signal.
|R1,R3||2||1/4W 5% RESISTOR||10K|
|R2||1||1/4W 5% RESISTOR||100K|
|MIC||1||ELECTRET MICROPHONE (or 3.5mm jack for connection)|
Due to it's low parts count, this circuit can be easily constructed on perf board or even directly soldered together. It can be housed in the actual microphone itself or a separate enclosure.