Audiobus: Use your music apps together.
What is Audiobus? — Audiobus is an award-winning music app for iPhone and iPad which lets you use your other music apps together. Chain effects on your favourite synth, run the output of apps or Audio Units into an app like GarageBand or Loopy, or select a different audio interface output for each app. Route MIDI between apps — drive a synth from a MIDI sequencer, or add an arpeggiator to your MIDI keyboard — or sync with your external MIDI gear. And control your entire setup from a MIDI controller.Download on the App Store
Audiobus is the app that makes the rest of your setup better.
ZOOM U 24...impressions
I though that I post my impressions of this audio interface that I finally broke down and bought it...if anyone is interested and looking for a decent interface with 2 in 4 out, and compatible with iOS 10.
First impression was the sound that came into my headphones just blew me away. Honestly. Like 3 dimensional and full, detailed sound that I never!! heard through (the same) headphones out of 3.5jack.
Now I understand what people were talking about with differences between the "headphones out" and lightning connection to external sound card.
U24 is instantly recognised in any app and gives choice of connection. I experimented with different hookups, like midi controllers BSPro and Edirol PCR 300.
They can be connected to midi in or into unpowered USB hub. Or combination of two.
I run it with RavPower 16000mA battery pack for few days now...and didn't notice much discharge, with 2 rechargeables of poor quality it lasted 3 hours.
The unit is pretty small, has a solid feel to it, including the pots and some are protected. It has a lot of panning, balancing between different inputs and outputs and headphones, muting etc...
What I don't like is that both inputs are mono. I had the impression that #2 was in stereo.
Connection to iPad is with USB 2 to USB B type and it is a nice fit.
Anyway if anyone has any questions ask.