Sound card microphone - Hobby Hour The microphone type which works best with computer sound cards is the electret microphone. Sound Blaster soundcards (SB16, SB32, AWE32, AWE64 or Live) from Creative Labs have a 3 (1/8 inch) pink stereo jack for the microphone input, with the following Computer Microphone – Circuit Wiring Diagrams card for a PC generally has a microphone input, speaker output and sometimes line inputs and outputs. The mic input is designed for dynamic microphones only in impedance range of 200 to 600 ohms. Lazar has adapted the sound card to use a common electret microphone using this circuit. He has made a composite amplifier using two transistors. Powering microphones - ePanorama This wiring is used in Fico CMP-202 Computer Microphone. Powering electret microphones with 3.5 mm mono jack form SB16. The following powering circuit can be used for powering electret microphones which want the bias voltage through where they output the audio signal.