Use headphone jack as line in for microphone on MacBook Pro Retina MacBook Pro Retinas dropped the line-in (microphone) jack that previous MacBook Pros had. Sometimes I want to plug in a 1/8" microphone, but there's no option to switch the input from "internal microphone" to "line in".



Is there a way through the command line or 3rd party utility to reverse the direction of the headphone jack to use it as a line in for a microphone?
For those Macs with a single shared input/output jack, the key to using a microphone is to have the correct plug. I'm guessing your're not seeing the input options because your microphone jack doesn't have three rings on it (Apple headsets with microphone have three rings)? If that's the case, you'll need to get a splitter cable so that the Mac realises that a microphone is available. See here for more information.