Running a motu though a digi 003 via an optical cable

Question

im running a motu though a digi 003 via an optical cable and it works great most of the time, but every now and again i get a spike in the signal.
is there anything that i can do about this?
any help would be greatly appreciated
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Answer 1

When you're connecting 2 digital devices via a digital audio cable you need to make sure they are running off the same clock, otherwise you will suffer from something called jitter. Jitter can manifest itself in a number of ways depending on its severity. Because both the devices you are using have good stable clocks you're not hearing it most of the time. But when their clocks do slip out of sync with each other a number of bits are getting read at the wrong value, which causes a click in your audio.
What you need to do is make both devices use the same clock. Since the 003 is the interface Logic uses I would suggest you use this as the master. You need to set the 8pre's clock source as ADAT. I've posted a screenshot below from our 2408 config. I don't know how similar they are but I hope it helps.
I would also make sure you always turn the 003 on first as many devices will automatically revert to their internal clock if they can't read one from the source you've set. I'd double-check the clock source the first couple of times you turn everything on.
Good luck with it.
And yes fer, of course the 003 transmits clock. Any digital audio connector transmits clock inherently. Receiving devices uses a phase locked loop to sync to it. I cannot believe your original response to this post went on about drivers. If a post about 2 digitally connected devices causing clicks does not scream jitter at you then you don't know half as much as you think you do. Please stop posting advice on things you know nothing about.
Message was edited by: Searmusic