003 / Lucid 88192 / Word Clock Problems

[geelo]

Hello,

This one's got me stumped ...maybe you can figure it out:

I use a 003 with an external Lucid 88192 converter on ADAT (PT LE v7.3, PPC G5, OS 10.4).

Until today, I have been syncing the Lucid to the 003 through ADAT. However, I wanted to make the switch to word clock since it's supposed to be a better form of sync between 2 digital devices.

I hooked up my BNC from the Lucid WC out the 003 WC in. In Hardware Setup in Pro Tools, I set the clock source to Word Clock, and I set the Lucid sync to Internal @ 44.1 (the session rate). The Word Clock light lit up on the 003, and I did not get any sync error messages in PT.

I immediately got ripping / clipping distortion from my tracks. The meters on the Lucid were clipping hard, but the Pro Tools levels were totally normal. As soon as I switched the sync back to ADAT, everything went back to normal. The Word Clock setting made the levels clip, and the sound was completely thrashed.

To make matters more confusing - I found a setting in the Lucid ADAT IN menu called "SRC" (Sample Rate Convertion). As soon as I turned that ON, (still using Lucid WC as the master clock), the levels were back to normal, and everything sounded great. The sessions is at 44.1, the Lucid Clock was set to 44.1 internal - so it should not of needed SRC.

So the big questions:
- Why did WC clip the levels, while ADAT sync was fine?
- Why did turning ON Sample Rate Conv. fix the problem?

Any help on this matter is greatly appreciated. Everything seems to be working fine now, but I feel strange leaving SRC on, when everything is tracked / played / converted at the same sample rate.

Thanks,
Geelo