All modern condenser microphones contain an internal constant source of polarization called an electret. However, any of these microphones has an amplifier inside, and therefore still requires power.
Instructions
Step 1
To connect an electret microphone with a built-in amplifier stage, which has two leads, first find out what supply voltage it is designed for: 1, 5 or 3 V. Then take a power source that generates the corresponding constant voltage. Take a resistor with a value of several kilo-ohms. The negative terminal of the microphone (it is connected to its body with a barely noticeable strip of metal, and if it is not visible, you can determine the corresponding terminal by dialing) connect directly to the negative of the power supply. Connect the positive terminal of the microphone to the positive terminal of the power supply not directly, but through a resistor with a nominal value of several kilo-ohms. Then connect the negative terminal of the microphone to the common wire of the audio device, and connect the junction point of the resistor with the positive terminal of the microphone to the input of the device through a capacitor with a capacity of several tenths of a microfarad.
Step 2
The domestic electret microphone of the MKE-3 type differs from the imported one in that, firstly, it is designed for a negative supply voltage of 4.5 V, and secondly, it already contains a current-limiting resistor inside it. Connect the black, blue or green conductor of the microphone to the common wire of the audio device and the positive of the power supply. From the yellow, orange or white wire, apply the signal to the line input of the device through the same capacitor as in the previous case. Connect the brown or red conductor of the microphone to the negative side of the power supply.
Step 3
In case you want to connect a microphone to your computer's sound card, please note that the resistor and capacitor are already there. But the parameters of the matching elements on the sound card are chosen such that the microphone must be designed for power supply with a voltage of 1.5 V. Any other will sound very quiet. Connect the negative terminal of the microphone simultaneously with the common and middle contacts of the plug, and the positive terminal with the far contact corresponding to the right channel.
