Ardour 3.4 OS X ---------------------- from MIDI recording with small latency to Audio recording ---------------------------------------------- for MIDI recording with small latency : 128 ( 2,7 ms) howto: 1.open jackPilot to choose SoundCard in Menu Preferences: in this case RME UCX UCX latency: 512 if needed: save Launch JackPilot 2.open VST Player 1.Load and check the Plugins before next step 2.in Setup: Driver CoreAudio Freface UCX choose an Optional VST Folder Input Device: Fireface UCX in Advanced settings; I/O Vector Size: we find: 512 or 64 (if session in Ardour was saved in Latency:128) Signal Vector Size we find: 64 3.launch Ardour in Menu Jack should be Latency: 512 change the Latency --> 128 for real time playing " Internal "sync is kept ( right from red rec button we should find in VST Player in Setup: Driver CoreAudio Freface UCX Input Device: Fireface UCX in Advanced; I/O Vector Size: : 64 Signal Vector Size : 64 we can see the CPU Utilization % and the Overload in ( Advanced ) for Audio recording of these MIDI tracks, that is to say to allow the audio recording routing in Ardour: in VST Player .in Setup: Input Device: Driver CoreAudio Fireface UCX should be replaced by CoreAudio Jack Router in Ardour in Menu Jack should be Latency: 512 ( change if needed ) BUT this causes crashes of VST Player after restart of the computer, and howto: should be done again……