I'm trying to record analogue stereo sound with my MacBookAir. The external mic is plugged to the headphones jack, but it is not being shown in the System Preferences. I did a little bit of research, and there is some rumor, that the headphone jack only supports digital-in for mics.

Is there a built-in way to use the analogue stereo sound without purchasing an external converter or a new mic? With my old MacBook 2,1 it was usual for me to do this, but with my new MacBook Air 4,1 it seems to be a tough task.