clock issue - lightpipe

[sleepingtiger]

Hello all,

I had a problem this evening with random "pops" showing up while record enabled on the channels in Protools which are being fed by my Digimax LT via lightpipe. These noises came randomly on different channels but showed up mostly on the second Digimax channel. I'm almost certain that it's a clock problem because it's the same noise that happens if I inadvertently leave my clock source setting to "internal" when using the Digimax for extra inputs. The noises are quick digital clicks that send the PT meters exactly to zero. Thing is, the "ADAT" setting is selected and the sample rates are agreeable. In other words, the settings are just as they should be. (I've checked and rechecked...) Recording and playback are normal in every other way. Also, the pops are very intermittent and sometimes don't occur at all for long stretches. In fact, after I powered everything down and restarted it took about five minutes before it happened, then it would happen about once every minute or two. When the setting is incorrect the pops are much more frequent as anyone knows that has selected the wrong clock source...

Anyone have any experience or suggestions? Usually, the Digimax is only used for transfers from analog tape. I've probably done about 20 of these since I got it in May and never noticed a problem. My 002 rack was recently serviced by Digi and brought up to revision spec in the process. Tonight is the second time I've used the lightpipe inputs since then. The first time for recording directly to Protools. As far as troubleshooting goes I've only had a chance to reseat the lightpipe connections and reboot the system. Tomorrow I'll try to get another Digimax to trade out from the folks I bought it from. In the meantime I thought I should post here to see if anyone has any ideas...

Thanks in advance!

[JFreak]

first of all, use a high-quality optical cable. i had once the same trouble which went away when i changed the cable. but it did come back later on, so...

you might unfortunately have some power harness cable connectors loosely connected, which means that the digital circuit board might get insufficient power and therefore not fuction properly. i did the brave thing and opened the case of my 002R, located what is the "power harness cable" and pressed each individual core tighter into the plastic connector - and all the problems just went away.

i also have the digimax lt, which works very nicely by the way. i also use digital external reverb via spdif i/o without any problems. i have set the ADAT to be the clock master.

[sleepingtiger]

JFreak,

Thanks for the reply. Two cables later the problem seems to have gone. If it comes back I'll try what you have suggested....

Take care,
+=G=+