Playing with an Electret Mic

photo 2(3)

Today I was playing with an Electret mic, salvaged from a bluetooth handsfree kit. I’ve not used a Electret mic before so it’s operation/preamp was of interest to me. It seems that most of these mics now include a single JFET common source amplifer in the mic can itself. As such they just need a single resistor and some biasing and they’re ready to go. The pic above shows the Mic internals.

In the video below I play with the Mic a bit and run a tone generator against the mic and show an FFT on my scope. A fun 5 minute project if nothing else…