-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 geoff wrote: > On Tue, 29 Dec 2009 18:49:16 +0000, geoff <[email protected]> wrote: > >> Hi there, >> >> I seem to have a jitter issue with external MIDI timing. > > Still stuck at ~30mS jitter. > > Booted with "hpet=force", and the kernel (and thus ALSA) found an > HPET, but the timing stayed the same. > > At Ralf's suggestion, I ran up Win XP Home SP2, installed the latest > MidiSport drivers, installed MIDI-OX and ran a loopback test. > > This relies on the accuracy of the MIDI-OX timestamping, but I seemed > to be getting a consistent 5mS round trip from the USB interface. > > Which seems to indicate there's a software level incompatibility with > USB MIDI (or at least, MidiSport USB MIDI) and 3.0b3. > > I'm looking for suggestions to ameliorate this situation. > something like http://www.philrees.co.uk/products/thruunit.htm#v4 or http://www.philrees.co.uk/products/thruunit.htm#v8
I have never needed or used these sorts of things, but it may be useful for you. > I'd also like to know whether it's worth me putting this on the 3.0b3 > bug list. If you can fill out a useful bug report then go for it. > > And can anyone describe their measured low-jitter external MIDI setup > with at least 4 ports, please? (where low is < 10mS) > I have a total of 3 midi devices (a keyboard, BCF2000, and a synth). I use the 2 ports on my Hammerfall. I also have a midisport 2x2 that I have not used for years. If I get some time over the next couple of days I will run that midi test. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAktEETQACgkQwRXgH3rKGfMW/gCgjD1X/9+3na6tRRG8qdkxNJux v1gAnj4vWqOpYi5IwlR50eisLnugibiP =hKvu -----END PGP SIGNATURE----- _______________________________________________ 64studio-users mailing list [email protected] http://lists.64studio.com/mailman/listinfo/64studio-users
