I would also be very interested in the answer to this as it pertains to my situation as well.
I want to record some guitar through amp modelling apps (such as Mobile Pod, JamUp Pro XT, and BIAS) into Pro Tools on my MacBook.
The Sonic Port seems capable, but what is the proper connection to my Pro Tools interface (Mbox Mini 2), Line in, Mic in, or Direct in?
What kind of signal is the top 1/4" jack actually sending? Documentation says guitar/line level. These are two different kinds of signals. Is it instrument level (like plugging into the guitar input of a tube amp) or is it line level? Or does it change from one to the other? Is there a switch, or does it happen automatically? I'm lost.
I initially tried connecting the guitar/line out signal into a line in on my Mbox, but it didnt seem to work right. The signal was very weak, even with the input trim on the Mbox at maximum.