In the video I have focused on illustrating how one might use two iPad synthesizer apps and a hardware synthesizer together including Cassini, Sunrizer, and the MKS-80. The BS3X is used as both the iPad interface and MKS-80 controller. No computer is required, but a simple change of cable allows for a computer to be integrated into this setup because the MOTU UltraLite interface and standalone mixer has MIDI I/O. In other words two MIDI interfaces are still necessary with a computer, but prior to this experiment I was only using the BS3X as a controller for the MKS-80 and bypassing the class compliant USB MIDI interface functionality. Since the USB hub was required I also added the QuNexus to the setup. This was dedicated to feeding notes into the arpeggiator in Cassini. The keyboard controller was split so that in the low end I could play the MKS-80 effect then tweak it with the BS3X knobs and sliders as it decayed. In the upper end of the same keyboard I played a lead sound programmed in Sunrizer.
See more at: audiocookbook.org/low-latency-wired-midi-with-ipad-and-bitstream-3x/
Cassini on the app store:
Sunrizer on the app store: