Well, I tried. And it didn't work. I had everything set up so it should work and it has worked before, so I have no idea why it didn't work this time. Next possible solution: Find out if my family's iPad has a better mic than my phone and headset. Or use duct tape to hold the phone as close to the Amp as physically possible. A shame my headset-solution didn't work as well as I had hoped... I almost managed to play something that sounded good...