j_e_f_f_g wrote:Use a midi controller that connects via usb (directly -- no hub).
USB passes the MIDI data (reliably?) through how many layers? USB always sends blockwise instead of bytewise. For example (ok, audio), RME ~tunnels USB sound cards for a reason, because if they used the USB protocol they would not have stable and fast audio processing.
My experience is that 5 pin MIDI is much more reliable than USB. The best would be CV.
j_e_f_f_g wrote:Yes, but that's an irrelevant point. Jitter is a problem only if/when a human detects it.
If you make music with several hardware devices and the computer (ALSA/jack) and each device has a different jitter it is a matter of luck what comes out at the end for music because each reacts differently. I don't like this kind of random (of the devices/software used) groove.
tramp wrote:However, well known is as well, that jack-midi never was done for interact with "hardware synthesizers". For hardware midi handling you indeed better use raw alsa.
Thanks for the information.
tramp wrote:That changed, when interaction with software midi devices steps up in the game.
jack-midi is handled in the realtime-audio thread of jack.
That sounds very good and so I and others "thought" it (from not dev point of view).
tramp wrote:The main issue is indeed the "conversation", or "bridge" from alsa to jack. That's were jitter may be introduced.
For ALSA "bridge"(a2j) and external hardware, could the adjustment of the timers and/or the rtmidi compensate the jitter?