I have an Allen & Heath ZEDR16, in A4 I’ve found that if I start jack first I am able to get partial MMC from the desk, however if I allow A4 to start jack I don’t get any midi interface from the desk.
Is this a known issue or am I doing it wrong?
Ardour offers the choice of which MIDI backend to use with JACK. If you use JACK2, which unfortunately most Linux uses do, neither of the available options are very good and you should use a2jmidid.
Probably worth reading this: http://www.manual.ardour.org/setting-up-your-system/setting-up-midi/