Good Buffer/Preamp circuit for electret mic
 

Hi,
I need to mic up some fiddles but I dont want to spend heaps on real instrument mics. I would like to build some mics using cheap electret inserts. I have tested the quality and it seems pretty good, but I read somewhere that they need a preamp for longer cables to reduce the impedance or something to prevent noise.
Does anyone know of a good discrete circuit to use that uses very few transistors? There's one that looks good on the net but uses heaps of transistors. What if I just put a simple class A amp like this?
http://www.tpub.com/content/neets/14...14179_89_1.jpg
I might use phantom power, and don't need a balanced output.

Hi Caleb,

That circuit is not suitable. If you intend to use a phantom power supply, you must have a balanced/differential output. Cheap electret inserts use to have a built-in impedance converting JFET. This circuit could work with a Panasonic WM-61 and phantom power (9-48 V).

http://www.twin-x.com/groupdiy/album...SH_Kit_Mic.gif

Roger