midi hesitation - glitchy playback stutter

[nuenemy]

i'm running 6.7 on 10.3.2 on G4 867mhz
with a motu A/V to a k2500sx & HUI

the problem: midi glitches when playing back (midi thru off)

example - i have 4 tracks of midi - drums/bass/keys/pad

every 10 measures or so the sequence will hesitate for a split second - similar to a drop-frame playing non-drop session hickup

if i stop & start the sequence within a few measures of the glitch...no problem

this is new since upgrading to 6.7 from 6.4 - no other changes - any ideas?

[Stig Eliassen]

Hi.

Well, I've had this problem several times, and to fix it I simply import all tracks into a new session. The problem occurs now and then when opening "old" sessions in PT after upgrading, as in your case.

[bizzle]

I sometimes have this problem too. When it starts happening I record all the midi parts back in to a track, and punch in when it gets out of time. Kinda sucky.

&e

[nuenemy]

thanks, i'll try importing tomorrow...

sucky is right

[nuenemy]

tried new session import - did NOT clear up the problem - in fact it seems the stuttering is becoming more pronounced - more like a sudden burst of backed up info - like something else in the system is getting priority

system usage shows nothing unusual

even playback of a single virtual midi track is now exhibiting the same glitchy stutter
& it doesn't happen at the same place every time - also, velocity now seems unstable as well - playing live midi thru, some notes jump out while others seem low by comparison

a couple of other notes about the system:

sync i/o - blackburst generator (i've tried switching clock to internal - no difference)
192 i/o
moto a/v usb

the only change is the upgrade to 6.7 from 6.4

VERY frustrating

[bizzle]

That sounds more severe than what I have experienced recently, I have the same setup too. Have you tried different USB ports? Try resetting the MTP, sometimes they get freaky. I have two identical setups in mine, just in case. I would also check your DAE settings, buffers etc. Are you using soft synths or hardware? Problem happens with one both?

&e

[nuenemy]

thanks for the suggestions - i'm beginning to believe the MTP is the problem - the playback stutter does not happen when the midi tracks are created with a virtual instrument, only via hardware

also, when i reassign a hardware created track to a virtual instrument(say a drum track) there are a lot of wierd 'events' that cause strange playback (i.e. notes MUTE themselves) - hese 'events' don't show up in the midi event editor, however

when i attempt to reset the MTP, it locks up (never did like that box!!)

the MTP IS on a 12' usb extension, but this never caused problem before - only since the 6.7 update - could be coincidence...