SPDIF

[Ken Forgettable]

Should be possible to bypass USB hardware entirely whilst providing for longer cable lengths by
using SPDIF - after the positional sensing is done of course

For an overview try: http://www.epanorama.net/documents/audio/spdif.html

[Synthex]

You can use the MIDI interface for longer cables.

[Synthex]

SPDIF is only digital audio, not MIDI data

[Ken Forgettable]

Looks to me like the spec' will allow this transport stream for anything.
...plenty of spare clock cycles going to waste there on the PIC