DIY-Central.com - Go Create something! - PCB Design, Electronics

This site http://scotthelmke.com/ showcases a lot of DIY microphones by the author. They look awesome. Here's a picture of a stereo microphone.



This mic is based on a pair of Transound TSB-55A cardioid electret capsules. These capsules are almost identical to the Panasonic WM-55A, but with a bit flatter low end. The two capsules are in a vertical stack, splayed out about 100 degrees. I really designed it to fit into a grand piano for live sound, but it does a nice general stereo recording as well.

I've also built stereo mics with the bigger, better Transound capsules. Those tend to be quieter, but not as flat as the TSB-55A.

Construction is a lot simpler than it looks. The body is just 1" ID copper water pipe, with the window cutouts done with a Dremel tool. The screen is brass mesh from McMaster-Carr. The capsule mount was made from various bits of brass from that little craft-metals display in the hardware store, and is mounted in a wooden plug that fits inside the mic body. Finally, the connector is a Switchcraft B4M, which fits the copper pipe almost perfectly. I used a piece rigid tubing to help the body of the connector fit nicely into mic body. This mic uses a small external power supply which is phantom-powered from a standard audio mixer. It would also be possible to build a simple power supply using a 9 volt battery and with an 1/8" stereo output, for use with a minidisc or other small recorder.

http://scotthelmke.com/stereo-mic.html

More DIY Microhones... http://scotthelmke.com/microphones.html

A DIY Tube Microphone.... and yes, it's a KIT!  What's even more awesome about this is the microphone body, grille and other stuff is included in the KIT.  Anybody that's into building DIY microphones know this is the most hardest thing to DIY... the microphone case. Not the electronics, not the power supply but the mechanical enclosure! So this kit packages everything nicely.

From the writeup:

Beautifully machined (unpainted) brass microphone body and head-grill assembly
Internal mounting cage assembly to mount circuit board, capsule, transformer and connector housings.

Components included

1 - 32mm/1in large diaphragm pressure gradient capsule (assembled)
1 - Plastic capsule mount
1 - Pre-amp circuit PCB
1 - Tube socket PCB
1 - Vacuum tube, 12AX7
1 - 9-pin tube socket
1 - 7-pin XLR male connector
2 - Ceramic insulators for both ends of C4

1 - Film Resistor,  1/2 W 10KΩ
1 - Film Resistor,  2W 100KΩ
2 - Film Resistor,  1/2 W 270KΩ
2 - Resistor, 51M
1 - Resistor, 200M
1 - Film Resistor, RJ 1/2 W 3KΩ
1 - Resistor, 1 KM
3 - Capacitor,  1μ/400V
2 - Capacitor,  .022μ/630V
1 - Capacitor,  1000 pF/630V
1 - Capacitor,  100μ/25V
3 - Capacitor,  0.1μ/63V
1 - Capacitor,  1000μ/10V
1 - Ceramic Capacitor, 2pF
1 - Transformer, turns ratio 10:1

1 - Fully assembled power supply
1 - Power cable for power supply
1 - 7-pin microphone cable

Printed documents
Schematic

I bought this kit on eBay and sure hope to find the time to build it.  I'll post pictures of my build.