SRC and clocking

[nedmann]

My question concerns real time sample rate conversions and clocking issues. For example:how does an 192 handle a asebu device
(pcm 91 or a nuverb). I know it can convert the incoming digital signal in real time using the digi card in the 192, but can it send clock to the pcm91 running at 41k or 48? (you could send it analog, but thats not my question.)
What about a gigistudio sending lightpipe at
44k or 48k- How do you clock the audio card in the PC running gigastudio?
Any insights would be most appreciated.

Ned Mann
Nedmann.com [img]images/icons/confused.gif[/img]

[DigiTechSupt]

-Yes, this is possible. You can choose the "base" rate (44.1/48 at all session rates) or wordclock (1 x session rate) for the Clock output of the master interface.

-If the Legacy port is in use, the interface will output SuperClock (256 x 44.1/48).


Brent

[nedmann]

I may not have made my question clear.
I worked with tech support on this and they said that when running a session at 96k the work clock output from a 192 will be a derivitive(44.1 or 48) of the sample rate. So one could clock a workstation runnung at 44.1 and have the output flow into a 96 or 192 session in real time.
But the asebu signal coming from the digicard on a 192 is not sample rate converted down. Therefore a dat or a pcm 91 cannot see signal from a 96k sesion and could not clock to the incoming asebu stream. Their testing confimed this. Is this correct?
Ned

[DigiTechSupt]

Ned,
Your assessment is correct. Not only would the word clock embedded in the AES/EBU output stream need downsampling, the data would need to be downsampled as well and framed correctly in the new sample rate.

Once a 96 kHz session is complete, the whole session should be bounced and then SRC after the bounce. The downsampling algorithms used in the bounce dialog employ downsampling techniques aimed to minimize aliasing when moving between coarse sample rates.

Brent