On Tue, 11 May 2004 19:49:18 +0100, Paul Burridge
wrote:

HI

Anyone know or care to guess what the typical impedance of a condenser
mic is?


I'll assume you mean an electret type microphone? I don't know of anyone who
makes a condensor microphone anymore. Those things take 500 volts of extremely
well filtered DC and the impedance is purely the capacitance of the plates.
Crooners hated them in the old days because if the stage electrician screwed up,
they could get the entire 500 volts on their lips as they 'kissed' the
microphone.

Figure 2.2k to 4.7k for electrets with three wires. On two wire types, set the
impedance with the bias resistor size. You can get more sensitivity by
increasing the drain resistor, but you sacrifice high frequency response and
dynamic range if you go too far with it.