We now offer a line of stereo adapters and microphones for iOS devices. They all offer powered stereo microphone inputs:
The sound professionals
I purchased one of these, and took it out for a test run last night. Set up was CA11 > CA-UBB > SP-iOS Adapter > iPhone 6 (using Twisted Wave app for recording, same app as I use with the Blue Mikey)
Bottom line, was it didn't work.
First issue, was that when the device was attached to my iPhone 6, it drained the phone battery even when not in use. I started out with a freshly charged iPhone on Airplane mode with no other apps open. Plugged it in about 15 minutes before the show started, but the battery was down to 89% by the time it started.
I recorded the opening act, who played for about 45 minutes. Battery was down to 64% after. My usual battery drain when recording with the iPhone using the Blue Mikey (with the Mikey's internal microphone or the line-in) is 10% an hour. This dropped about 15% in 45 minutes. I'm guessing this thing draws power from the lightning port. Not enough to power the Mics without a battery box, but enough to drain the battery.
When the main act came on stage, for whatever reason the iPhone stopped detecting the device and would only record from the internal phone microphone (yuk!). Tried rebooting the phone, no luck. I was running my usual PCM-M10 rig as well, so I didn't miss the show....but I didn't wind up recording any of the main act with the phone. I tried to get it to work during the set break, and it looked like it was recording, but then wouldn't record once the show started again. The iPhone 6 I was using is my older phone. I tried it on my regular iPhone 6s as well, and it wasn't detected there either. Also tried without the battery box, but no luck.
As for the recording quality, I did successfully record the opening act. Unfortunately, there was a lot of hiss in the recording. Much more than I get with the Blue Mikey line-in, or my regular PCM-M10 set up.
I am going to do some further tests just to make sure it's not the app or the phone (unlikely, because I tried two different phones). I guess it's back to the drawing board.