I am supervising a student project which involves using your Model 10A mike. We need to know how to interface it to a two-transistor pre-amp circuit, gain approx 20, with capacitor coupled input. Does it need its own power supply ?
The model 10A is a dynamic microphone. Its "power source" is an internal permanent magnet.
The 10A audio output is balanced, i.e., the audio signal is on pin 2, and the audio signal is also on pin 3 but 180 degrees out of polarity with pin 2. If your preamp design is not a balanced input (differential input), use pin 2 for the audio "hot" and ground pin 3.
Pin 1 is case ground and does not carry audio; it must be connected to your chassis ground.
The audio output signal will be around 0.00015 volts (.15 mV) assuming an input signal that is typical conversation level: not whispering and not yelling.
The output impedance of the 10A is 180 ohms.