24/96 clocking problem! Please help :)

[Joe_caithness]

Not a sexy topic, but here goes.

I run two M Audio 2496 cards alongside each other, using their multiple device interface in the driver.


2496 card one works like this:

SPDIF OUT goes to DAC1, feeds analogue
SPDIF IN goes to Mytek AD, captures analogue

Mytek is the master clock.


2496 card two works like this:

SPDIF OUT goes to DACMagic Plus, feeds monitors

M Audio card is the master clock, as it can only LOCK to something else if it sees an spdif input


Whatever you do, the second card has clocking glitches, audible on feedback/sustained notes/test tones.

So it doesn't capture glitches, but I hear them, making me second guess.

SO..

I try all the different configurations, capture AD and monitor DA on same card, second card always glitches.


I am presuming that the M Audio drivers are confused, one card has its clock from the Mytek, one is generating it's own. When you try and put this info into my DAW (cubase) it gets confused, and audible clicks happen as the two drift (every few seconds).


SO.

I want to find a way to solve this.

My first thoughts are to clock everything to the Mytek, as it has a good clock and some IO.

But uh oh, the DACMagic Plus has no wordclock in BNC socket.

So, plug it into the M Audio 2496 right? well that only has SPDIF... so I this point I think, hurrah! I know! I'll take the wordclock out from the Mytek and convert it to an RCA and whack it into the second cards SPDIF IN, thus completing the chain..

Will not lock, doesn't seem to see it.. I take it you simply can't just throw Wordclock down an SPDIF cable when it's expecting wordclock and digital audio in one?


Any ideas????????

this images might help!!!!!!!




benchmark-dac-one-rear-panel.jpg

http://www.mytekdigital.com/images/p...2adc-72dpi.jpg (wouldn't let me do a pic link for this one?)

cambridgedacmagicplus.jpg



IDEA: Do I simply need a way to get clock from the mytek and distribute it into the second 24/96, is that possible?

[bonestonne]

The two 2496 units should be sync'd together. Doing this will change a few things, primarily, your digital output options.

Now, if you sync the two 2496 units, you run them into each other, and just pick one and set it to external sync, the cards would be fine.

My question is that if you do this, what outputs are you going to be losing? You have the two RCA on each card, that could give you one stereo input, and you could set one to drive your monitors. Alternatively, you could run the one that you pick for output into the DacMagic using RCA, and run that out to your monitors, etc as wanted.

This would remove the MyTek from the mix completely, and that's where I believe the problem lies. The sync just isn't with the right units.

Feel free to entertain the idea, or try to tell me why you want to run things a different way, I ran two Delta 1010's with world clock until I moved to a 1010AI box, now I am yet to set up the S/PDIF sync for full use, since I'm not usually recording with all the cards at once, I don't have a clock problem right now...

[Joe_caithness]

The two 2496 units should be sync'd together. Doing this will change a few things, primarily, your digital output options.

Now, if you sync the two 2496 units, you run them into each other, and just pick one and set it to external sync, the cards would be fine.

My question is that if you do this, what outputs are you going to be losing? You have the two RCA on each card, that could give you one stereo input, and you could set one to drive your monitors. Alternatively, you could run the one that you pick for output into the DacMagic using RCA, and run that out to your monitors, etc as wanted.

This would remove the MyTek from the mix completely, and that's where I believe the problem lies. The sync just isn't with the right units.

Feel free to entertain the idea, or try to tell me why you want to run things a different way, I ran two Delta 1010's with world clock until I moved to a 1010AI box, now I am yet to set up the S/PDIF sync for full use, since I'm not usually recording with all the cards at once, I don't have a clock problem right now...

Hey thanks for chiming in.

I would not want to lose the Mytek as I spent the best part of a grand on it!

I'll have a further think about it, but using the actually AD and DA on the card isn't an option as I run a high end mastering suite.

[16bit]

I assume the two cards have to be linked via S/PDIF to work to the same clock, so on Card 1 S/PDIF Out to the Card 2 S/PDIF in.

That should leave one digital I/O spread across both cards.
Could you not try this:
Run the Mytek S/PDIF Out into card 1 S/PDFI in
Run card 1 S/PDIF Out to card 1 S/PDIF in
Run card 2 S/PDIF Out to DAC1
Run card 2 Analogue out to monitors

Remove the DacMagic from the system, and keep the others. I'm not sure if you can actually receive a clock source externally and use it for multiple cards, or that the card feeding the second will just refuse to accept an incomming digital clock. It's worth a try.