sync, clock and time code relations

Swell · 24th August 2009

Hello,

I need your help to make things clear in my head about sync, clock and Time Code.
I have experience in working the sounds on films imported in my pro tools session but not sync with deck. I now integrated a facility with lot's of vodeo formats and decks...which I'll have to lay back in or capture the content.

The equipment I have to work with is the following: Pro Tools HD with 2x192 interfaces and sync I/O.
I loop all 192's to my sync I/O. The sync I/O is locked on INTERNAL and is the LOOPMASTER. Is that correct ?
I have video REF comming from house to snyc I/O and remote 9pin out of it. I also feed the sync I/O with the video signal itself.
I get how the remote work, I get how you make pro tools being the master transport and time code slave. Now it is not that clear for me what's the relation with Time Code and clock...

Is time code replacing the clock when it comes from a betacam ? Does it sync with the remote 9 pin or the video ref ?
In which case which element is the master clock ? Isn't it always to sync I/O ? Does the 192 interfaces always locked themselves to the sync I/O ?

Please excuse my ignorance and help me understand the basic graph of it.

hummer · 24th August 2009

Your most basic problem is that you should be syncing to video ref, not internal clock.

Your 48 kHz clock signal is derived from a common video black that should also be the master for the video decks you are connecting to. This way, everyone is always on the same frame edge, and digital audio clocks will all be synchronized to these frame edges.

This takes care of your timing references, now you can talk about positional reference (time code), which is completely independent of your clocking signals. In short, pro tools chases the incoming LTC so that it plays back in sync with the video on the tape.

Hope that helps a bit.

Swell · 24th August 2009

Ok then, if I get you, the sync I/O should be lock on "video ref" and the 192 interfaces on the loop synch. Is that right ?

Thank you ! It does help me.

Audio_Vision · 24th August 2009

Also, make sure your positional reference is set correctly. If you only have the 9 pin connection between the Sync I/O and the video deck, you would use serial timecode as positional reference. This is changed in the session setup window (PT 8).

hummer · 25th August 2009

Quote:

Originally Posted by Swell

Ok then, if I get you, the sync I/O should be lock on "video ref" and the 192 interfaces on the loop synch. Is that right ?

Thank you ! It does help me.

Correct.

24th August 2009	#1
Swell Gear interested Joined: Nov 2008 Posts: 29 Thread Starter	sync, clock and time code relations Hello, I need your help to make things clear in my head about sync, clock and Time Code. I have experience in working the sounds on films imported in my pro tools session but not sync with deck. I now integrated a facility with lot's of vodeo formats and decks...which I'll have to lay back in or capture the content. The equipment I have to work with is the following: Pro Tools HD with 2x192 interfaces and sync I/O. I loop all 192's to my sync I/O. The sync I/O is locked on INTERNAL and is the LOOPMASTER. Is that correct ? I have video REF comming from house to snyc I/O and remote 9pin out of it. I also feed the sync I/O with the video signal itself. I get how the remote work, I get how you make pro tools being the master transport and time code slave. Now it is not that clear for me what's the relation with Time Code and clock... Is time code replacing the clock when it comes from a betacam ? Does it sync with the remote 9 pin or the video ref ? In which case which element is the master clock ? Isn't it always to sync I/O ? Does the 192 interfaces always locked themselves to the sync I/O ? Please excuse my ignorance and help me understand the basic graph of it.

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24th August 2009	#2
hummer Gear maniac Joined: Oct 2006 Location: NYC Posts: 150	Your most basic problem is that you should be syncing to video ref, not internal clock. Your 48 kHz clock signal is derived from a common video black that should also be the master for the video decks you are connecting to. This way, everyone is always on the same frame edge, and digital audio clocks will all be synchronized to these frame edges. This takes care of your timing references, now you can talk about positional reference (time code), which is completely independent of your clocking signals. In short, pro tools chases the incoming LTC so that it plays back in sync with the video on the tape. Hope that helps a bit.

24th August 2009	#4
Audio_Vision Gear interested Joined: Jul 2009 Location: Baltimore Posts: 13	Also, make sure your positional reference is set correctly. If you only have the 9 pin connection between the Sync I/O and the video deck, you would use serial timecode as positional reference. This is changed in the session setup window (PT 8).