Yes I agree that's normally how I have done it as well.

That is the circuit you would you with a 2-terminal microphone which has a common-source amplifier.
This one has a common drain amplifier (as @Bordodynov has drawn it), so the drain terminal should go to a low impedance supply of 1.3V to 3V. It could be regulated with a bandgap reference, or even an LED, and have a large value capacitor in parallel for lowest noise.

 

Hello,

As the microphone has 3 connections, R1 can be directly decoupled.

Bertus

 

OK, folks!! Just how much noise are you talking about?? And in what frequency bands??

 

OK, folks!! Just how much noise are you talking about?? And in what frequency bands??

Take a close look at my pictures. They have all the answers to your questions.

 

See

 

OK, folks!! Just how much noise are you talking about?? And in what frequency bands??

The biggest contribution will be the self-noise of the microphone. That is quoted as being equivalent to 28dBA acoustic noise. That's not great for a microphone. An AKG C451 is about 18dBA. Dynamic microphones are quieter.

 

OK, as for " how much noise", I see plots in nanovolts and one plot in microvolts. And I am thinking that the desired signal output is at least a couple of hundred MILLIVOLTS. That would put the noise voltage at least 60dB down, or better. For most audio work that is fairly good. For amateur audio work it is excellent.

 

OK, as for " how much noise", I see plots in nanovolts and one plot in microvolts. And I am thinking that the desired signal output is at least a couple of hundred MILLIVOLTS. That would put the noise voltage at least 60dB down, or better. For most audio work that is fairly good. For amateur audio work it is excellent.

The gain was set for x100 (40dB), and the sensitivity is -33dBV/Pa. That would give (in theory) +7dBV at 1Pa which is 94dBA.
0dBm (-2.2dBV) output would be at 85dBA.
The self noise is quoted at being equivalent to 28dBA, so that's a SNR of 57dB.
Obviously, the choice of gain is arbitrary, and the self noise is fixed so you can have any (within reason) SNR that you would like to specify!
Change the gain to 20dB, 0dBm output would be at 105dBAm and SNR has gone up to 77dB.