Ah, seems you’re right. I didn’t know that. But that seems to be an old way of doing it. I’ve only ever seen 2 contacts on a seperate microphone jack or the 4-contact combined ones in modern laptops.
Regardless, if it doesn’t require the bias pin, the mic is self-biased or biased through another source (use the same wire for the signal to get bias, this is easy, you just use a cap to decouple the signal from the bias).
Ah, seems you’re right. I didn’t know that. But that seems to be an old way of doing it. I’ve only ever seen 2 contacts on a seperate microphone jack or the 4-contact combined ones in modern laptops.
http://tuxgraphics.org/npa/condenser-mic-on-usb-sound-card/
The link doesn’t open, says connection refused 🤷.
Regardless, if it doesn’t require the bias pin, the mic is self-biased or biased through another source (use the same wire for the signal to get bias, this is easy, you just use a cap to decouple the signal from the bias).