8mm Forum: Pulse Sync

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Posted by Adam Deierling (Member # 2307) on January 19, 2013, 10:01 AM:

Can anyone tell me exactly how this works? I hear people talk about it all the time and never once have they explained how it works... Thanks!

Posted by Douglas Meltzer (Member # 28) on January 19, 2013, 10:19 AM:

Adam,

Let me know if this thread helps. Pedro's site shows his amazing sync boxes.

Doug

Posted by Lee Mannering (Member # 728) on January 19, 2013, 10:52 AM:

The Cresta Sim-Sync was always a popular choice for movie makers which comprised the black box unit, modified sound projector and usually a Fostex of Philips cassette recorder. A friend, sadly no longer with us used this system for all his movie making and once the sound track was completed on tape he then recorded it to sound stripe. A pulse (signal)generating system is a electronic way of locking two units together so they maintain sync. Versatile cine cameras also offered internal ac sync signals such a Beaulieu via a cable you could link to a suitable tape recorder.

Elmo also had pulse sync cine cameras and the Elmo DR-1 cassette recorder worked well with them. Once your film came back from processing you could stripe it, connect your cassette recorder to the Elmo GS1200 with a pulse cable and having switched the ESS switch over transfer the tape audio direct to mag on the film. I’m sure someone will come in who knows more about the expandability of the Elmo ESS system although I know a few have also linked them to computer for re-recording now.

Posted by Hugh Thompson Scott (Member # 2922) on January 19, 2013, 01:12 PM:

Some of the systems used sprocketed tape,it was either a strobe
light or a needle on a dial where sync could be adjusted if necessary.All the systems worked quite well,as there were quite a few different variations, and it was deemed the best way of compiling a soundtrack without the need to record directly onto
the striped film,something a lot of projector manufacturers
forgot.It also made it possible for owners of silent projectors to
have a soundtrack to their films.

Posted by Adam Deierling (Member # 2307) on January 19, 2013, 01:33 PM:

If i have a gs1200 and a dvd player how hard is it to sync up a movie?

Posted by Hugh Thompson Scott (Member # 2922) on January 19, 2013, 02:46 PM:

The man to get in touch with would be John Clancy, Adam.
Thereis a piece of equipment that is used between the GS and
the dvd player that ensures sync on recordings, John is the man
to speak with on this.

Posted by Douglas Meltzer (Member # 28) on January 19, 2013, 03:59 PM:

Adam,

Without pulse sync, the projector and the DVD would sync up for a few minutes at most, then drift apart. I have done re-recordings with and without a sync box and it's a breeze with the box.

Doug

Posted by Mark Mander (Member # 340) on January 19, 2013, 04:15 PM:

http://www.ffr-film.de/index.php?page=elmo&header=&language=de

Quarzbaustein für GS1200,scroll down for this item.

try these for a sync unit,it's the one i use on the GS1200 and they work really well.

Posted by Mike Peckham (Member # 16) on January 19, 2013, 05:38 PM:

The crystal sync box is great for running a DVD in perfect sync with a cine film on a GS 1200. It's not necessary to connect the DVD player to the GS as the sync box locks the projector at a constant 25 fps.

The trick is to start both the DVD and the GS at exactly the same point on the film. Like Doug, I have re-recorded the sound track on commercially produced prints from a DVD using the sync box with excellant results. When re-recording, it is usually best to do it reel by reel.

You can also project a film and run the DVD for the sound track, I have done this too, but in order for it to work, you need to splice the film on to larger reels in such a way that they match the DVD frame for frame at changeovers. It's essential therefore to check that the print matches the DVD. I've done this with several films, most successfully with Derann's print of Grease. I mounted it on 2 x 1200ft reels and managed to match up the change overs to the DVD, it was therfore possibly to start the DVD and the first reel in sync and they would remain in sync for the whole 1200ft.

It's fiddly, but very satisfying. [Wink]

Mike

Posted by Mark Norton (Member # 165) on January 20, 2013, 10:34 AM:

Hi,
I've used one of Pero's sync boxes for years and regularly show synced to CD home made super 8 silent movies ( Kodak 100D Fuji V50D) and have re-recorded many super 8 package features and trailers.
I bought the top of the range box at the time, it transformed many of my films that had less than top notch sound from my collection and also has allowed me to make home movies and later add sound tracks. Well worth the outlay.

Posted by Ricky Daniels (Member # 95) on January 20, 2013, 12:15 PM:

I must confess, I too like Mike have projected Grease and many more features with a Pedro box onto the big screen with accompanying DVD 5.1 audio and although a fiddle is immensely satisfying... just remember where those sync advance and retard buttons are located when it's dark [Big Grin]

Best,
Rick

Posted by Alan Rik (Member # 73) on January 20, 2013, 12:43 PM:

Just remember that in the US the DVD's playback on the NTSC system which means they are running 23.97 fps.
So you have to make sure that the projector is running at the same speed. The Pedro box you need unfortunately is the most expensive one.

Posted by Winbert Hutahaean (Member # 58) on January 20, 2013, 02:36 PM:

I still don't understand too why we still need that pedro box to be placed in between DVD and the projector.

We knew that DVD has 99.99% constant speed. So if there is a drift it must be because the projector has the speed change (up and/or down). So my understanding that it is the projector that needs a box to maintain the speed at NTSC or PAL frame rates.

And isn't that crystal sync. button found on GS is for that purposes?

Explanation please.

Posted by Oscar Iniesta (Member # 1731) on January 20, 2013, 04:19 PM:

I still found it a little mess. There are two devices at FFR shop. One makes the GS to work at constant speed, and the other uses the sound from a digital source to control the GS speed. So, if Winter is right, and a digital player is near 100% constant speed, we only need the crystal quartz to get the GS run at fixed speed. I live in europe, so I would need 25fps on the GS and it would run ok while my CD, PC or DVD plays sound. It´s ok? So why to use the expensive device which takes the audio L and R channels? It is better because can modify the GS speed when we have a drop in the player?
I am talking about the devices FFR sell. I know the Pedro Box offers many others advantages.
In an old post, you were talking about using the PC and a GS input to get the desired speed. Did it really work?

Posted by Mike Peckham (Member # 16) on January 20, 2013, 04:25 PM:

quote:
I still don't understand too why we still need that pedro box to be placed in between DVD and the projector.

We don't. The Pedro box is attached to the projector only and locks it at a specific frame rate, in Europe that's 25 fps. The DVD is automatically locked at that frame rate due to the cyles in the mains voltage. in Europe it's 50 cycles, therefore DVDs in Europe play at 25 fps (50/2 = 25).

There is no connection between the DVD player and the projector. The projector is simply locked at the frame rate of the DVD.

Simples [Wink]

Mike

Posted by John Clancy (Member # 49) on January 21, 2013, 03:47 AM:

The Pedro box is the way to go. Mike and Doug have told all that is needed and all you have to do now is purchase said box. As you are in an NTSC country you will need to the more expensive box unless you want to play PAL sourced video only through your system. Simpler to just purchase the more expensive box.

We have demonstrated all manner of sync' pulse systems at the BFCC over the years and the Pedro box is the easiest solution we've come across. Works perfectly.

I did a sync' pulse show last week where my copy of Star Trek The Deadly Years has bad sound stripes. I transferred the film to hard disc using the Pedro box for locked in 25fps sync' then cut the episode off the DVD to match exactly and created a copy on DVD to match the Super 8 print frame for frame. It's then just a question of getting the two in sync' at the start of a show.

Posted by Bill Brandenstein (Member # 892) on January 21, 2013, 12:50 PM:

Several years ago, John gave me the same advice (thank you again, John), because the 23.976 fps rate of US video is a troublesome little problem. But the Pedro boxes were too expensive for my budget. Since I'm pretty comfortable working in A/V software, the solution was to buy his unit designed for working from an external input, the P1008GS-P, which outputs to the Elmo GS1200MO only. So the timing and audio becomes computer-dependent, which creates several other technical problems depending on the audio hardware, operating system, and audio software in question. Still, I've had success with this. Using multitrack software and two separate audio output jacks, you create a control track (short tone bursts at the interval of 2,0002 samples apart at 48KHz audio sample rate) and send it to one output connected to the Pedro box, and send the audio to another to be connected to an amplifier and speakers.

This is cumbersome in some respects, but everything has its advantages and disadvantages, and I like the exactitude this setup affords. And the fact that nothing special nor expensive in additional tools is necessary.

At this forum there was once a discussion about feeding a squared-off pulse directly from a computer sound card to the input of the GS-1200’s ESS control input, but apparently not all sound cards have the correct electrical characteristics to make the signal “read” by the Elmo. I tried this and it sure didn’t work with my gear. So the P1008GS-P was a reasonably priced solution to keep it all in the computer.

Posted by Winbert Hutahaean (Member # 58) on January 21, 2013, 02:08 PM:

If the trouble is because the frame rate at NTSC a bit lower from 24 fps (hence the speed is lower) what do you guys think with today`s many software (like Audicy or many VideoDJ software) that has speed adjustment feature (up/down)?.

This means we play the DVD through that software and speed up a bit to get to 24 fps instead of using that more expensive pedro?

any idea?

Posted by Alan Rik (Member # 73) on January 21, 2013, 03:39 PM:

Actually the easier way to do it is to use the software to slow down the GS1200 so that it plays back at the 23.97 FPS.
I am using Logic Pro and generate a sync signal at 23.97fps, connect the computer to my GS1200 using the DIN cable to 1/8 inch audio cable going into the ESS input, and then start the DVD at the same time as the GS and Voila! Sync! It works great unless there are missing frames.
Here I am re-recording Poltergeist.

Posted by Oscar Iniesta (Member # 1731) on January 21, 2013, 04:10 PM:

Alan, that´s great! You have an all in one device. You have the DVD player, sound controls and the pulse generator in your PC.

Posted by Bill Brandenstein (Member # 892) on January 21, 2013, 11:34 PM:

Nicely done, Alan. Can you give us more detail on how you created the pulse wave, what your sound card is, and what you did to get the 1/8th inch cable correctly matched to the DIN pins for the ESS input?

Call it Pulse Sync for Dummies...)

Thanks!

Posted by Ricky Daniels (Member # 95) on January 23, 2013, 04:50 AM:

Alan,

Nicely done and great to see a modern solution for us pulse syncers...

However (and I know I'll have to wash out my mouth with soap after I say this) when you are pulse syncing and see the quality of the material providing the audio against the 8mm print it does beggar the question why do we bother especially when you see 1080 on a big screen!?

I'll now go and punish myself for daring to question why... [Eek!]

Best,
Rick

Posted by Mark Mander (Member # 340) on January 23, 2013, 10:21 AM:

Nothing wrong with that comment Ricky,It's a fact,I enjoy re-recording films and it really improves the viewing experience when it's done,Mark.

Posted by Ronald Kwiatkowski (Member # 3349) on January 23, 2013, 01:22 PM:

Very interesting thread. I was considering a solution with the stuff I have, that is a laptop and a dj controller. You'd use the dj wheel to speed up or slow down the playback of the sound file, also you could start the playback with near-to-null delay (if you're a classy dj [Big Grin]

) at a specific leader number.

The pulse sync solution with Logic Pro however seems quite perfect to me, and still affordable. I imagine you could have a Logic file with different language tracks, all in 5.1.

Posted by Winbert Hutahaean (Member # 58) on January 23, 2013, 02:09 PM:

Ronald ...that is exactly what I was thinking when posted this;

http://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=004777

As you are aware about the DJ thingy you knew that there is now a time-coded vinyl where the signal pulse is produced by vinyls to control the audio from MP3 in the computer.

I was thinking to record the signal pulse to magnetic track and then the sound coming out from the projector is hooked to the DJ software where the audio is ready.

When the projector is slowing down, the audio is also going to slowing down, right? Exactly like what happen when DJ is using time-coded cinyl.

In this regard, the sound on MP3 will never drift with the projector, right?

Posted by Alan Rik (Member # 73) on January 23, 2013, 03:52 PM:

Well lucky for me I had the help of an Audio Engineer who did the hard work. I just had to sync it up!
But he told me that he used the Test Oscillator plug in on Logic Pro to create a WAV File that was 23.97. Then he created a Loop of it. Then with the 1/8 inch to DIN plug he said he found a diagram somewhere on the web to find the right connections.
Yes..I used an outside source! For a brain much bigger than my own! [Smile]

Posted by Ronald Kwiatkowski (Member # 3349) on January 23, 2013, 04:00 PM:

I suppose this should work, but you'd have to have the right pulse signal (frequecy? pulse length?) and you'd have to make sure that while recording the pulse to the magnetic stripe, that there's no noticeable change in speed. If there's a "wow" while recording you'd always repeat that "wow" while playing back. This is in theory, as far as my understanding goes. Personaly, I prefer a solution that keeps the audio straight on and "unwowed", which means the projector is the slave and the image speeds up or slows down accordingly.

Posted by Bill Brandenstein (Member # 892) on January 28, 2013, 12:21 AM:

Ronald, you're absolutely right about the potential for "wow" problems, but the only way to completely eliminate that as a possibility with a GS-1200 is to slave it to a digitally-sourced track and have nothing to do with the projector's sound. Still, in most cases, 'wow' is not a noticable problem.

Alan, thanks for the details, and was hoping you would be able to give some of those engineering details. But perhaps not. However, knowing what your computer's audio hardware is would at least give us one working model that's directly compatible.

Posted by Jim Schrader (Member # 9) on January 07, 2015, 09:13 AM:

And only after a year Pedro's site is down is there a way to contact him? Or does anybody here in the US have one of his boxes? Will the box work with ST1200HD's?

Posted by Andrew Woodcock (Member # 3260) on January 07, 2015, 01:26 PM:

Jim the boxes are only suitable for use with D.C. electronically controlled driven machines. The ST is not this type of machine and therefore could never work with Pedro's sync boxes.

Directly the boxes work with Braun Visacoustic 2000 models as well as the Elmo GS1200.

In theory, they should also be compatible with the Sankyo 800 Stereo model but he never advertised an interface for this model.

Via an interface that Pedro provided or fitted himself, the boxes also work with Bauer Studioline models like the T610, Beaulieu 708el as well as one or two of the best super 8 editor's, e.g. Goko RM8008.

They will not work with the Eumig S938/940 models for the same reasons as the ST1200's

[ January 07, 2015, 06:36 PM: Message edited by: Andrew Woodcock ]

Posted by Jim Schrader (Member # 9) on January 07, 2015, 03:55 PM:

Thanks Andrew

Posted by Michael De Angelis (Member # 91) on January 08, 2015, 10:44 AM:

Previous discussion about sync: follow this link from this forum.

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