I'm thinking about using my MixPre-D as a USB interface for my iPhone for field recording, thus keeping the signal from having to convert to analog again (and again to digital) after the mixpre's A/D conversion. Has anyone done this, and does anyone have any recommendations for good app's to use to do the recording?
I tried this with a mixpre-d and an Android tablet (so same idea) and it worked fine,but, and this is the rub, it had slightly more self-noise than running a line level out into a recorder. A surprise to me, but testing was pretty rigorous. Given that using a rugged mixpre-d to an iPad/iPod/nexus is not very field use friendly either, so it would better on all grounds to use line out xlrs. Of course, the aes output may be better, but I suspect not: the da converter on the mixpre-d is not as good as on the usb-pre2. Hope this helps.
I've used a usbpre2 with my iphone 4s and works really well. Use Rode Rec, it's a great app for recording. Not sure if it's the same with a MixPre but when I updated the iOS the interface stopped working with it. I've not tried it on the iPhone 6.