Hi marsxmarsx,
Maybe an USB Host to Midi Converter like " Kenton Midi USB Host " solve your issue.
Connect the
- M-Audio Axiom Air 32
- Maudio Oxygen 25
- M-Audio Axiom Air 61
- Samson Graphite 49
to your USB Hub with external electrical power supply and go from the USB Hub into the
- “Kenton Midi USB Host” with external electrical power supply
and from the " Kenton USB Host to Midi" Converter > Midi output into the
- UR 44 Midi input
and from the UR 44 via USB to the iPAD
Don’t forget to accommodate all devices with external electrical power supply.
I can’t give you an warranty that it’s works as you expected, that is only an idea from me to solve your issue.
We had no experience with the “Kenton Midi USB Host” converter.
Please let us all know if you solved it in this way.
But the easiest way is to connect the Samson Graphite 49 or the M-Audio Axiom Air 61 directly to the UR 44 Midi in.
I know it’s not possible simultaneously without an Midi Interface, but better than nothing.
best Jan