Traditionally recorded my mixes in Serato DJ with a DDJ-SX2 but having since selling my controller and going back to using my SL2 i need to run a line into my mac to record with Audacity.
Not overly fussed about using the same computer to record as to play from but i can’t seem to change the jack port settings from speaker/headphone to line-in input.
They removed that feature with the retina models (2012) I believe, so just headphone/mic combo jacks since.
You might be able to trick the input into thinking it’s a mic but then you’d have to worry about proper gain levels and it’s still mono so it wouldn’t be worth the headache.