[Jack-Devel] Considering JamRouter, a low-jitter MIDI bridge for all Jack versions

[Ralf Mardorf]

Hi Carlo,

I'm tired of discussing this issue and I guess a lot of people prefer
that I stopped discussing it ;).

I found this one from 2015:

http://linux-audio.4202.n7.nabble.com/MIDI-jitter-Was-outfitting-a-computer-for-songwriting-in-linux-td96796.html

And this one from 2010:

http://lalists.stanford.edu/lad/2010/07/0189.html

Note, I didn't read it again, so I don't know how useful or useless it
is.

I found this one where I was whining about another issue, but I claimed
that "Jack MIDI latency test is ok", much likely it should read "ALSA
MIDI latency test" ;). It looks like I already unbound an USB port
sharing an IRQ with the HDSP. On my new mobo I can't do this, but the
shared IRQ seems not to affect the HDSP at all.

I changed my hardware, my current setup looks like this:

[rocketmouse at archlinux ~]$ amidi -l
Dir Device    Name
IO  hw:0,0    HDSPMx579bcc MIDI 1
IO  hw:1,0    TerraTec EWX24/96 MIDI
IO  hw:4,0,0  Scarlett 18i20 USB MIDI 1

apart from this I switched from an around ten year old AMD machine to
an Intel machine, so now a perhaps better timer is available, let alone
that I can use a lower audio frame value when launching jackd, which
seemingly has impact on the midi-audio-sync-accuracy, too.

Actually the audible issue did arise, when I tried to record one
external MIDI instrument after the other, if all were recorded at the
same time, it was more or less ok.

I didn't use my new machine for critical MIDI recordings, maybe I will
do during the German North Rhine-Westphalia summer holidays from
2017/07/17 to 2017/08/29. I'm working in childcare, so I have holidays
myself at the moment.

Regards,
Ralf