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……