DIY Microphone – How to build a Condenser Microphone for recording for about $20 in parts. Or build a lavalier microphone for use with a video camera.

The original design is from Tape Op issue #16. The article and schematic is still available on line at

http://www.prosoundweb.com/recording/tapeop/buildmic/buildmic_16_1.shtml

Here is a recent parts list. 8-20-2007

www.digikey.com

The Mic Element
WM-61a Panasonic
digikey part #
P9925-ND
$1.86

10uF Metalized Poly Capacitor
digikey part #
EF2106-ND
$4.48

2.2k ohm metal film Resistor
digikey part #
2.21KXBK-ND
5 for $.49

1000 pF ceramic Disc Capacitor
Digikey part #
1457PH-ND
10 for $1.97

9 volt battery holder/clip with leads
digikey part #
BH9V-W-ND
$.86

A possible supplier for XLR connectors

http://www.fullcompass.com

Full Compass Parts will be cheaper in bulk. This is as high as they could be.

NC3MDL-1 XLR 3pin Male Panel Connector
$2.70

NC3FDL-1 XLR Female Panel Conector
$2.82

This is the old style I used for the mic itself. It’s a bit difficult to put the mic element in the end.
NC3MX Male XLR Connector
$2.52

This part will be more money, but could make assembly way easier.
NC3MRC 3pin XLR Male Right Angle
$7.42

Then you need point to point wire for inside the box.

Thin very flexible wire for wiring to the mic itself.

Solder and irons. Heat shrink tubing can be useful.

Junction boxes and covers.
Screws to mount the panel XLR connectors.

Other Misc; A metal file – The knock-outs on the junction boxes are just a tad small for the Neutrik XLR panel connectors, so the hole on the ends will have to be enlarged. I have tried everything and a simple metal file (round) is the answer.

Drill Bits to make the hole for the screws for the panel Connectors. These Have to be able to drill into really hard metal (ie Buy a FEW).

One tube of 5 min epoxy will do for many Mics.

A 9 volt battery.

Something to test it with. (ie a mixer and headphones, and mic cables)

Hardest part of the whole thing is soldering the back of the mic, it is small and if you leave your iron on it for to long it will fry the mic electronics.

Suggestion buy some extra mic elements – they are cheap.

As far as my lavalier modification is concerned, you can use the wire that comes with inexpensive headphones if you want to sacrifice a set. And you will need something like an alligator clip to attach the mic to the speakers clothing.

They are similar to earthworks or any or small diaphragm microphones, they do not have a color to them, the microphones sound like how the instrument or voice sounds in that room.