pitch problems with focusrite octopre and Digi002

[larb]

MacPro1, 2x2GHz Dual Core Intel Xeon, Mac OSX 10.4.9, Protools LE version 7.3.1, Digi002, Focusrite Octopre Platinum.

Clock source: internal, optical cable connection between units, hear ticking on all octopre inputs.

Clock source: optical, sample rate 48: Sessions record as and sound higher in pitch than originally performed.

Clock source: optical, set sample rate to 44.1, seems to work.

When protools is set to 44.1kHz before opening session and sessions are opened in 44.1kHz, it seems to work. When set or recorded at 48kHz, no matter how we configure the settings, the session sounds shifted up in pitch (by about a whole step).

I can fool a session, originally recorded in 48kHz, to sound at the proper pitch by changing the octopre to 44.1, even though the session is at 48kHz. In this case, the Digi002 blinks 44.1kHz, the tracks sound to the true pitch. I am able to bounce in this configuration but it does not bounce sounding the same pitch as I was able to hear it while I was bouncing. The Digi002 is not able to be the clock with the focusrite, apparently. The Focusrite Octopre may not be the unit for us. Any suggestions for a fix or suggestions as to a better, more compatible way to access the 8 optical channels available to the Digi002?
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[Mikeren]

Hi Larb,

All I can say is that I have the Octopre and 002R and never have a problem. I actually like the combination very much.

Here are the rules of the game: When using the Octopre (i.e. recording) the Digi must be set to optical external and the Digi and Octo must be set to the same sample rate.

If you playback with the Octopre connected and Digi set to external the sample rate of the session and the Octopre must also match.

Generally, for playback, you won't need the Octopre and can set the Digi to internal at the sessions sample rate.

As for your odd happenings, it is possible to have a session set to 48 and still record at 44.1 if you are clocking externally and haven't changed the Octo to match the session rate.

Summary: Make sure sample rates match between the Octopre and Digi at all times, and you must set the Octopre as master clock (Digi set to external optical). If you are simply playing back the Digi can be set to internal at the matching sample rate. Note that a (previous) session may not be recorded at the apparent sample rate if you did not carefully follow the above rules before recording, as in your example of the 48 session that only clocks properly at 44.1 external. Lastly, if bouncing for a CD, you will have to convert rates higher than 44.1 to 44.1 in the bounce dialog. Any difference in sample rates is perceived as a pitch change, BTW.

I hope this helps,

MR

[larb]

Thanks for your reply, MR. The thing is... I am clear that the Octopre was set the same as the Digi002 when these recordings were made. When I play them back, set the same as they were recorded, they sound higher in pitch. The same is true when I remove the Octopre and set the digi to internal clock. The only way to have a session sound the same as it was recorded is to record in 44.1. I do not have a big problem with being limited to 44.1... something just seems wrong that the sessions recorded, and played back, at 48kHz do not translate. Thanks for your thoughts and help...

Larb

[Mikeren]

Sorry I didn't get back right away. I'm pretty sure I'm right about the cause of your problem, it happens to others and the symptoms are the same...
http://duc.digidesign.com/showflat.p...part=1#1242661 (and these folks give the fix).

As far as future recordings, the real test would be to set the Octopre to 48, set the Digi to 48 external, check your optical connections and record. Then, without changing anything play it back. If it is not the correct pitch I'll shut up.

MR