Simple PTMP question regarding syncing

[Therminologist]

Hi, just a very quick question, I am trying to hook up a CD player via S/PDIF into PTMP 7.4cs4 through my brandnew Profire 2626. I'd like to record a session at a moderate 48kHz/24-bits, and set the Profire 2626 be the master clock for all my devices, but the audio quality of the S/PDIF signal is, at least to my ears, unsatisfactory (a real iffy sound and not full-scale). Since the clocking is set not from within Pro Tools (as was the case on my old 001 and PTLE 6.4) but through the control panel, I need to quit PT, set the clock to S/PDIF, and restart PT. Now when I attempt to open the session, it throws an error message at me that the session was saved at a higher sample rate than is currently supported by the clock (or something to that extent).



In addition to that, I'm having a hard time connecting all the other digital gear (both ADAT ports are to be used simultaneously) and to get them to talk 'clock' with one another. Push come to shove, I am willing to record at 44.1/24 if that helps the S/PDIF signal from the CD player, but since the CD can only give clock to one device (the Profire) at at time, the other 2 ADAT devices (my old 001 daisy-chained through an RME Hammerfall DSP 9632 on a second PC and an Emu 1010 on the host machine) are left without clock and wouldn't play at all (or with a lot of clicks and pops).

Am I right in assuming that it isn't possible to work in one session at 48/24 with a digital CD signal without going analogue? Because that would really be beside the point of having an interface with so much connectivity, right?

Here's a very crude diagram of what I'd like the setup to do:

<font class="small">Code:<hr /><pre>

Out ----Clock-------> In
PROFIRE2626 ADAT 1 Emu 1212 ADAT (slave)
In <----------------- Out





Out -----------Clock-------------> In

PROFIRE2626 ADAT 2 RME Hammerfall ADAT
Digi 001 ADAT In
In <---- Out <--- Out

</pre><hr />


Is this actually possible? Or am I missing a point?
Any help greatly appreciated!

Jay

[Therminologist]

*bump* Any ideas at all?

[MDog]

The CD standard is 44.1k sample rate. If you saved your session at 48k, the clock from the CD player is sending the "wrong" sample rate. You need to convert that 44.1k digital stream to 48k somehow. Or like you say, simply save your Pro Tools session at 44.1k. It may be easier to convert your 48k audio files to 44.1k and import them into a new 44.1k session.

As far as syncing, I use an Apogee Mini-Me on S/PDIF "A" as my clock. I also have a PreSonus Firestation in standalone mode on the ADAT buss. I have the ProFire 2626 slaved to the Apogee and the PreSonus slaved to the ProFire. IOW, the clock is Apogee (master) to ProFire 2626 (slave) to Presonus (slave). Works perfectly for me anyway.

Hope this helps.

[Therminologist]

Hi, thanks for the reply. I've now bitten the bullet and am using an analogue CD signal after all. The whole idea was to be able to drop some CD audio into any session (regardless of sample rate) without closing Pro Tools altogether and slaving the 2626 to the CD player. In an ideal world, I would use wordclock for the syncing of all the digital gear I own, but the 001 doesn't have wordclock (let alone my CD player). I'm now slaving the 2626 to my 001 via ADAT and the Emu to the 001 via S/PDIF (which is unusual but it works). Personally I think that the inability to switch clock from within PT is one of M-Powered's biggest disadvantages, but I guess I have to live with it!

Cheers,
J

[Matt Radlauer]

When doing a digital to digtal transfer, you have to match the sample rate and the bit depth of the device.

Using 48k/24bit is forcing your device to up-convert. This is why it sounds bad. SPDIF is pretty much the same on every device.

Given the age of your Digi001, I would make the 2626 the master. The clock in the 2626 is pretty good as far I can tell so far.

You should never be slaving your interface to a CD player...

Like I said...match bit rate and sample resolution and your spdif transfer will work just fine.

[Matt Radlauer]

When doing a digital to digtal transfer, you have to match the sample rate and the bit depth of the media.

Using 48k/24bit is forcing your device to up-convert. This is why it sounds bad. SPDIF is pretty much the same on every device.

Given the age of your Digi001, I would make the 2626 the master. The clock in the 2626 is pretty good as far I can tell so far.

You should never be slaving your interface to a CD player...

Like I said...match bit rate and sample resolution and your spdif transfer will work just fine.