Setting up Single Clock Source

[jd1234]

Can anyone explain how to set up a single clock source for the following workflow with MBox Pro?

I have one channel set up with API A2D (preamp & converter in one) into MBox Pro using SPDIF. The channel i want to set up is Neve 1073 preamp into Rosetta 200 A/D converter into MBox Pro. I'd also like to run the Rosetta into MBox Pro with a SPDIF connection. I am looking to record off both of these rigs at the same time.

Do they make SPDIF/Midi/Worldclock cables that have 2 SPDIF In's so both chains can go into MBOX with SPDIF connectors? If so than how can i chose the Rosetta as the Master Clock? Is there a better way to do this than trying to run both of these rigs into MBOX with SPDIFs?

Any help or suggestions would be appreciated.

[albee1952]

I'm not convinced that you can use both devices at the same time with Mbox PRO. It has a single SPDIF input that is 2 channel. I would feed the API A2D into that and connect the Neve via analog(Line input 3 or 4). Set Pro Tools to use SPDIF as the clock source, and done(sell the Rosetta and add a second Neve?) The Mbox converters are totally adequate(IMHO). Just one opinion

[jd1234]

Actually I think I can use Wordclock BNC connectors out of the Rosetta into the MBox Pro and keep API A2D with SPDIF. Would that work?

If i do that and set the Clock Source to WordClock in Protools will everything sync up with WordClock? Will the SPIDF connection from A2D automatically sync up? Or Is there other changes i need to make in protools or on the units themselves to make it work?

[cwsand]

Originally Posted by jd1234

Actually I think I can use Wordclock BNC connectors out of the Rosetta into the MBox Pro and keep API A2D with SPDIF. Would that work?

If i do that and set the Clock Source to WordClock in Protools will everything sync up with WordClock? Will the SPIDF connection from A2D automatically sync up? Or Is there other changes i need to make in protools or on the units themselves to make it work?

You should set the clock source on the devices themselves. Anytime you have 2 devices connected digitally, one should be the master clock source. So if you want your MBox to be the master, you'd set it to Internal, and your other devices would use BNC or S/PDIF as clock sources depending on how they're connected.


You may have to experiment. You could also set them up in a chain like I have where the TCE is synced via Wordclock from the Saffire 56 and the Saffire is synced via Wordclock from the Presonus Digimax. For some reason, if I set the Saffire to internal and try to sync the Digimax via S/PDIF, I get horrible clicks. Your devices should have some indication of when the clock sync is locked.

[jd1234]

Okay thanks for the reply. To be honest though I am still confused. If I have one device using WordClock, one using SPIDIF and then Internal (Mbox itself), I can only select “one” source as the master correct? And I make the change in Pro Tools itself on the drop down menu for clock source right?
In this case I’d like to use the Word Clock, so I would select that and then all the units would sync to that?

You said I have to set the devices themselves too? Where do I do that? In Pro-Tools? There is no buttons or switches on the devices that say internal/external or master/slave or anything like that.

I am assuming you mean change the settings in ProTools? If so where? Is there a place where you can assign the other units as slaves? Cause just to be clear the only selection I know how to make is assigning the master clock in Pro Tools but I don’t know how to assign the slaves to the master. I was assuming it synced up automatically.

[BScout]

Word Clock is just a cable to send clock. It is not the clock itself.

Something has to be the MASTER clock and then that SENDS clock by Word Clock to everything else. There are other ways to send clock too (including all other digital signal will have clock embedded and the device receiving the digital signal on input can derive the clock from the digital signal)

If anything digital is not receiving clock (by any type of cable) from the MASTER clock, then it will not clock. That means there has to be a digital cable or word clock cable going from the output of the MASTER clock device to an input on the other device. Then you set the other device to listen to the clock coming on that input. If your device is only connected with a cables going from its outputs, it obviously has nothing coming in on an input so it WILL NOT CLOCK. So that either needs to be the MASTER clock (set to internal) or it needs fixing with a digital cable or word clock going to an input. Clock can come in on a digital input even if you aren't using the digital input for receiving anything.

There can only be one master clock in a normal system.

Pro Tools needs a clock to. You can set it to be the master clock (set to INTERNAL for the Audio Interface it is using) or it can listen to signal coming from the master clock (set it to a digital input or word clock on your Audio Interface that Pro Tools is using)

But basically, clock follows the same rules as everything else in audio. It flows from output to input.