On Tue, 05 Jan 2010 21:27:32 -0700, Gustin Johnson <[email protected]> wrote: <snip> >-----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.
Thanks for the suggestion. I had a configuration similar to that in the early 90s. To prevent the "drummer" sounding increasingly drunk as more (high controller density) parts were added to the piece, I replaced it with a Unitor 8, an eight port MIDI interface of the period. It doesn't take much stacking on a single MIDI cable to bring that inebriation about, imho. Plus, you need a switch box for patch editing, which is a pita. <snip> >> >> 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. Thanks for considering this. _______________________________________________ 64studio-users mailing list [email protected] http://lists.64studio.com/mailman/listinfo/64studio-users
