No line input on 2015/16 retina MacBooks?

[BeatCrazy]

I'm doing some experimenting with capturing line-level audio (not microphone) into iZotope RX 5, and the software won't recognize a valid audio capture input. I've tried the CalDigit USB-C dock audio input, as well as a $9 USB adapter, that appears to offer only headphone and mic input.

Apparently on the old MacBooks you could toggle the headphone jack to be line input, but no more on these new models?

 

[Zazoh]

The audio jack does appear to handle input as well.

"Use the headphone jack to connect external speakers and headphones. You can also use this port with iPhone–compatible headsets (with microphone and remote)."
https://support.apple.com/en-us/HT204303

 

[BeatCrazy]

The audio jack does appear to handle input as well.

"Use the headphone jack to connect external speakers and headphones. You can also use this port with iPhone–compatible headsets (with microphone and remote)."
https://support.apple.com/en-us/HT204303

Ya, but "mic" input on that port is different than a line-level input.