Is there an objective way of determining the quality of a wordclock source? I'm running a setup of an Apple G4 computer, Digi 001 digital recording system, Spirit 328 digital console and a MOTU MTP AV interface. I'm using the MTP AV as wordclock master, as I was told it was superior to the wordclock of the 328. There is a recent software upgrade of the 328 which claims to have a better wordclock than its previous versions. But how can you tell if it's better than, say, the MTP AV?
Technical Editor Hugh Robjohns replies: The only pukka way to check the quality of your wordclock is to test it with a digital testset designed to measure jitter, sampling frequency and drift. Unless you can track down a friendly digital‑audio test engineer with a suitable test‑set, you aren't going to have much luck, I'm afraid.
Most desks at the Spirit/Yamaha 0‑series end of the market have relatively poor wordclocks, so it makes a lot of sense to run everything from a purpose‑designed reference unit.
The effects of bad jitter are to raise the level of background noise very slightly, particularly at high frequencies, and to cause increased vagueness in stereo imaging. Neither are very easy to hear under normal monitoring conditions.
If I were you, I think I'd continue using the MOTU as a clock master — the practical advantages of having a single, identifiable master which you can easily distribute to your other digital equipment far outweighs the worth of having the Spirit upgraded.