For anyone interested in DIY microphone building, Frank Piesik has open sourced his printable, compact stereo microphone (via createdigitalmusic.com) –
I wanted to have a mic which I could use for general purpose recording in conjunction with my old iriver h120 (with rockbox installed). I didn’t find a suitable mic without a build in recorder:)
So after a little bit googleing I found this article about a low-cost homebrew solution and decided to get a bunch of these panasonic wm61-capsules described in the article to start experimenting with them – here is the result.
A special feature of this microphone is it’s variable stereo width (by time-of-arrival stereophony).
The button near the audio jack is the on/off-switch, the second one a gain boost. By swapping two resistors in the circuit, the gain boost could be easily converted to a gain damp. The preamp circuit isn’t necessary at all, if your recorders preamp has phantom power. But the 9v battery increases the headroom for louder signals and powers the 4 capsules more convenient. The distance between capsules and preamp shoud be as short as possible.