Quote Originally Posted by GovernorSilver View Post
I tried to record my guitar using a Roland Duo Capture EX audio interface. When I try tapping Record, I do not hear the guitar. It seems Record only works with the iPad/iPhone mic, not with USB audio input. Is this correct?
Yes correct, it is only designed for a basic quick convenient recording using the built-in mic.

If you want to do more than this using your Duo Capture you would export the audio to GarageBand or similar and record your guitar on to another track, (plus you would have control on mixing, effects, adding additional tracks etc.)