Here’s the little pre-amp circuit used inside the mic:
The op-amp used is a microchip MCP6241, also not shown is a 5v power regulator for the circuit (not quite built yet) and the wiring for the jack plug and power switch (which are both fairly self explanatory, with the exception of the jack plug used as a switch to connect/disconnect ground to the circuit and thus act as a secondary on switch).
Here are a couple of photos of the mic with the electronics almost finished:
Will post a final set of details once the mic is totally finished.
Here’s a quick project I’ve been working on for a couple of evenings. It’s a low fidelity (i.e probably crap sounding) mic, preamp and enclosure.
The microphone I’ve had knocking around for ages and is stolen from a really old rotary phone. The body of the mic is made from a metal world-cup promotional Budweiser bottle (which are surprisingly sturdy, been trying to find somewhere that’s still selling them). The ‘cage’ is made from plywood and threaded brass rod. I haven’t built the preamp yet but will post the schematic when I get around to it.
Still need to do a hell of a lot of tidying up of the case and end cap.