USB MIDI has got the risk to cause noticeable MIDI jitter.
Does USB MIDI provide galvanic isolation? Several times I read claims
that USB MIDI connections aren't galvanically isolated.
Standard MIDI connectors make usage of opto-couplers and shield of the
MIDI DIN connectors is open.
Certainly all of the USB MIDI connections I have ever tested, are
not galvanically isolated; I always get trouble with USB signals
bleeding over where they don't belong. USB-to-DIN adapters I have
used have been better, but not perfect. Is there a make/model of
USB-to-DIN (or even PCI-to-DIN if it exists anymore) which you know
for sure has opto-coupling? That would be a great boon to me.
Sooner or later I'm going to do optocoupling for audio too, probably
using a TOSLink setup.