ADAT Bridge playback problem/Mix Plus system

Hi folks, I hesitate to even post for advice on this, it's the most needle in a haystack problem I've ever had. Here we go: System: -G4 silver door dual 1gHZ, 1g ram -Mix Core, Mix Farm, DSP Farm cards (in that order) -888/24 (channels 1-8) -ADAT Bridge feeding 2 Presonus Digimax FS 8-channel ad/da units (channels 9-24) I have been using this setup for quite some time, the Digimax units being the most recent additions about 6 months ago. Since then, NO problems, all good. These units clock from either optical or word clock input, always have worked fine with optical setting, always glitchy on wordclock setting. I received tracks from a live concert recorded on an HD system with the Digi console, that whole rig. Don't know many more details about that end. I started working with these tracks and at first it seemed fine (though now it's one of those situations where I can't swear there were no problems first, but I didn't notice for a while at least). They were PT7, so I just made a new session and dragged them all in (48k, 24 bit). The problem is that the ones I'm routing through the ADAT bridge/Presonus combo have intermittent ticks in them. These are never in the same place, here and there on any given track going out 9 through 24, averaging maybe one tick somewhere per 10-15 seconds. If I route these to the 888, they are fine. However, lest you think I just have some f-ed up setup with the optical cables, etc. I can be having these glitches, close that session, open any other session that I've worked on here, recorded here, whatever, and it is fine immediately. Close that, open the problem session back up and problem is right back. I've also started with a new session, re-importing the same tracks, problem follows. I have tried switching 4 different optical cables in all configs of 2 sets of in and out, problem remains the same. Is there some sort of time-bomb planted in PT7/HD audio files to not work with SOME old digi hardware or???!??!!!.... Thanks in advance to anyone who cares to wade in here. J. Ward

I had a somewhat similar problem where the original recording engineer had the playback buffer too low to record 24 tracks at once (128?) However, they (the digital 'snits'--I call them) didn't move around, I had to go into sample level and "de-snap" all the tracks with the pencil tool. It did help my editing and zooming speed by the time I was done the next day. However, if they are in 'random/ moving places' now & you're mixing. I would try running the 8192 buffer to see if the playback engine is contributing. If that's no help, there's definitely some type of clocking error happening. Perhaps someone else can offer some insight too. Good luck!

Hey, Thanks for chiming in. What is the "8192 buffer" and how do I run it? I thought I was pretty up on (vintage) PT technology, but?... J. Ward