8mm Forum: Star Wars Re-record, Logic Express and a 2 Macs!

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Posted by Alan Rik (Member # 73) on October 25, 2007, 11:43 PM:

Ok. I remember a post a few months back where a forum member Joerg had used his computer to sync with his GS to re-record a feature.
Well he said because of the limitations of the software it was only tested on 25fps Pal.
I kept thinking there must be a way to do that here in the states yes? So I had a friend of mine who is much more technically minded to help me out on this one and here is the outcome:
He created a 23.976 wave file and then inserted it into the software Logic Express. Then I found the appropriate DIN plug to 1/8 stereo jack and used one Macbook to run Logic Express and to continually loop the wave file. Once this was connected to my GS1200 it kept the projector at a perfect 23.976 NTSC standard speed.
Then with my other computer I used to play the DVD back and the outputs of that went into the Line Inputs of the GS.
Outcome? Beautiful insync Stereo sound Re-recording that sounds 100% better than the original track. And it did not wander except a little at the reel changes. (It was spliced on 2x1200 ft reels).
It sounds so great that Poltergeist is next! I love Pedro's box and I wish I could afford it but this worked exactly the same. And it only cost me $9.00 for the cable from Mouser Electronics!
Sync has arrived for NTSC! :

Posted by Bill Brandenstein (Member # 892) on October 25, 2007, 11:54 PM:

That's extremely cool, Alan.

When I attempted a direct sound-card-to-Elmo control connection, I couldn't get it to work. So I bought Pedro's cheapest ($99) box, and I feed 1Khz bursts to it and let it control the GS that way. And guys, 23.976 is a cinch to do at 48Khz sample rate: your bursts are exactly 2002 samples apart. 44.1 is a different matter, but that's only a problem if you're trying to put the pulses on a CD.

Alan, would you mind giving some exact details on what the waveform was in Logic and how the cable was wired?

Posted by Kevin Faulkner (Member # 6) on October 26, 2007, 05:14 AM:

Better still Alan how about putting the wave file her on the forum for others to download.

Good to find another Mac owner. I use my Mac Mini all the time now. I dont have a Windows PC now but run windows on the Mac Mini if I really need to and thats rare.

Kev.

Posted by Joerg Niggemann (Member # 611) on October 26, 2007, 06:37 AM:

You don't even need a PC or MAC to play back a sync pulse. Once you have the appropriate file, burn it to an audio CD and use a cheap CD Player to sync the GS :-)

Posted by Bill Brandenstein (Member # 892) on October 26, 2007, 02:40 PM:

I'd be happy to upload my pulse-trigger files (how to do that, Kevin?), especially the 48Khz one that is only a little over 1MB zipped! But the 44Khz version is 164MB -- I'll have to see what the minimum repetition length is.

I'd concluded that what Alan tried wouldn't work because the equipment's -10dB line-level audio out (CD, computer, Tascam DA-88) didn't match the Elmo's ESS electrical characteristics. So I was wrong, but then it raises the question of what was REALLY wrong.

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