USD and 888/24 and sample rate problem

[Boom Chic]

I just recorded a session via AES/EBU direct into Pro Tools via inputs 3 and 4 on my 888/24 at 48khz from a Digibeta deck which is 48 khz 16bit. I used the USD to synch ProTools for recording. Problem is when I play back the sound in Pro Tools, it seems to be playing back at 44.1, and the pitch is lower than the original source material, but its is still in synch with the picture that was imported via Miro DC 30. All frame rates and sample rates were confirmed prior to this session. My 888/24 is somehow playing back 44.1khz even though it says 48khz on the front panel (48khz is selected in both the hardware setup dialogue box and the Session Setup window).

When I turn off the USD, aha! The session plays back at the correct speed, and in synch with the picture. What the heck am I doing wrong? Is my USD setup configured wrong? Did I do something wrong when I digitised (using LTC and the Video ref/VITC synch options).

I've never had this problem before, but this is also the first time I record via the AES/EBU synched up to a video source.

Mac OS 8.6
448 megs of RAM
9600/350 with Newer G3 500/250
888/24
USD
Pro Tools Mix Plus vers 5.01
Miro DC 30 Plus
Studio 5 LX
Mackie HUI

Please help.
Thanks.



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Karen Basset
Boom Chic Studios
Los Angeles, C A 90048
www.boomchic.com

[spigots]

What sample rate was hitting AES in 1 and 2 of the 888 when you were digitizing?

[Boom Chic]

Channels 1 and 2 were set to analog, only channels 3 and 4 were used to digitise the AES/EBU audio at 48Khz.



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Karen Basset
Boom Chic Studios
Los Angeles, C A 90048
www.boomchic.com

[spigots]

Just got back from the Stars game. Your Kings kicked our ass.
If memory serves me correctly, to digitize from a non-WC capable digital video source, (DV, Dig Beta, D-2, etc) Pro Tools would need to sync to Digital In, which it derives from the 888's AES 1/2 input. (digital/digital in the apple+2 setup.) If there was a 44.1 ref, or no ref hitting that input, it could be a big problem.

Any one else is free to jump in here.

Please

The USD part of this is baffling. I'm sure by now you have brought the whole system down and back up, and let the USD reboot itself. Is your Video ref to the USD stable? I have had the experience of bad video black and it's no fun.
good luck
frank

[Danny Caccavo]

You have to have AES1-2 seeing your digital clock source. Just like DA-88's.

DC

[Boom Chic]

Thanks for all your replies. I don't know why I digitised via inputs 3 and 4 and not 1 and 2, but I did. I've since switched to 1 and 2 on my 888 AES/EBU for digital inputs.

I've updated my USD firmwre to the current version, which seemed to help, but upon opening up the session the next day, same problem.

When I digitised, I had my session sample rate at 48kHz and sync to digital, and I was online and in sync with the digibeta deck via the USD. In my Session Setup window, I had the clock reference set to video ref and the positional ref set to auto LTC/VITC as I always do when I digitise from video into Pro Tools, the only difference this time was that I was recording audio via AES/EBU instead of analog.

I just changed the clock ref setting in my Session Setup window to Internal/VSO and VIOLA, I'm back in business. Everything is in sync., at the right pitch, sample rate, etc.

What would be the correct procedure next time I want to perform this same recording process? i.e. AES/EBU into Pro Tools from a Digibeta deck as the master. When I say master, it is both the master for the digital audio clock (I presume) and for synching Pro Tools to the Video ref and LTC/VITC signals.
And what would be the layback procedure? How do I get the Digibeta deck to synch it's AES/EBU inputs to Pro Tools AES/EBU outs?

I'm a little confused about the whole synch issue because I am both synched via Pro Tools being "online" to the video source and the digital synchthing with the 1 and 2 AES/EBU inputs. Could someone clear this up for me?

Sorry for the long post, but I think all the info is there. Thanks again for all your feedback.

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Karen Basset
Boom Chic Studios
Los Angeles, C A 90048
www.boomchic.com

[Jan Folkson]

I'll agree with my friend Danny here. To record dig into PT the best way is to input into AES 1/2. Those are the only two ins that will receive clock. The only other way to do this would be to have your 888s slave to your USD and have the USD resolved to the same clock as your digital source. Sync issues get the better of us all at some point.

I'd retrack the audio using either clocking solution above.

HTH.

- Jan

[Boom Chic]

Coco,
Yes, I used the video ref as my clock source.



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Karen Basset
Boom Chic Studios
Los Angeles, C A 90048
www.boomchic.com

[jwh1192]

When you layback to the Digibeta...
Use the same blackburst as you did on the layoff...If you can, use the same AES out of the Digibeta to clock Pro Tools...
I beleive the problem you had in the first place is that you were trying to run your session without switching the master back to Pro Tools after doing you layoff. If you were continuing to see AES clock from the Digibeta then all would be fine but you did not seem to be doing that. Does your Digibeta live in your audio room all the time or do you only use it when you need it. I wish that Digibetas had wordclock inputs on them. Have you tried clocking the Digibeta to the AES outputs of Pro Tools yet...on your layback?I had a similar problem clocking an O3D and A DA-88 to a Digibeta several years ago. I was told by Sony that they have a different type of clock ref. coming out of the AES outs...pain in the ass. ended up returning audio from the Digibeta analog. If I can help I would be happy to...leave me e-mail [email protected] am in LA.....always like to dig into clock issues...they are the worst...

[COCO]

BC: But what I'm asking is: did you route your video signal from the deck into the vid ref input of the USD. I'm not sure you've answered that.
COCO

[This message has been edited by COCO (edited January 01, 2001).]