Problems with timecode sync and SD 788t mixer

[Matthew Rogers]

Hey gang, I am currently working on a feature where we are syncing timecode straight from a SoundDevices 788T straight into two MX red's via a lemo cable (xlr to lemo.) We did a test today when we got a minute because when we would jam the two cameras and the slate from the mixer, the slate would always be a second ahead of the two reds. However, the audio guy said he's always had a problem with the RED's being a second behind, where as I had never seen that before. To make matters worse, when we recorded the slate running and then pulled it into RCX, on one clip the timecode on the slate was 6 frames different compared to 1 frame in the next clip (same camera.) I am really scratching my head on that one because when we shot the first clip, we were actually wired into the the mixer. Do you still have to hit record to sync timecode?

The mixer says he's set at 23.976, so 29.97 shouldn't be an issue.

Not sure what to do since it's so freakin messed up. Would love any advice on what might be wrong. It would be very nice for post if things lined up correctly.

Matthew

 

[Sam Winzar]

With the whole "RED being a second behind" thing it's one of the quirks of how RED displays the timecode. You should find that when you watch the recorded clips that the timecode is perfectly in sync. It's my understanding that the issue is that RED's live timecode display on the camera is a second behind.

I know that doesn't help with your main issue, but something I thought should be clarified. With timecode, I've had the most success having a lockit box attached to the camera at all times and using that as the master timecode that you sync the slate and mixer to.

 

[David M. Geary]

You don't need to hit record to jam sync via a lemo cable, if the RED is set to jam sync you should see the link icon once you jam from your SD788. I've seen the 1sec lag on the RED, I wouldn't call it common but it happens. If you're doing long takes and it's critical, might want to consider a lockit box on the camera which solves a lot of these issues. It also helps if you hot swap the batteries to minimize how often you have to jam it.

 

[Rainer Fritz]

The live TC in the Displays is always off.... but when you look into the files in RCX or QT proxy you will see that they match if it is synced correctly (and your TC slate is configured correct). I shot my last productions always with a ambient lockit box and did autosync in avid... worked like a charme.
Be sure at the sounddevice recorder that u use the jam sync menu. if you use the 24h mode u are not using the built in ambient acl chip tc generator.
You need to go into the TC menu, set TC and then JAM. Only then the TC generator in the sounddevice is activated.
The 24h mode uses only the simple timeclock and this is not stable and always off.
As I saw, ONLY the sounddevice recorders which have the acl chip implemented are stable enough (1ppm). With all other sound recorders we used a second lockit box to be sure to be sync.

 

[Matthew Rogers]

Thank you Rainer, what you said was the exact problem. We switched the 788T over to the other mode, and it jammed perfectly with the RED to the exact same frame!

Thanks for the info, it got me a free beer from the sound guy

Matthew

 

[Rainer Fritz]

thats great... enjoy the beer...

 

[tadeo garcia]

Hello, I don't have a lockit box but am trying to jam my TS-C. Any suggestions? Thanks!

 

[Christopher Mills]

Should be a simple cable just like the r1 tc cable..
from 788 to tsc, switch off the ts-c, then switch it on.
the led in the middle of the tc readout should blink once per second when you are jammed.

if you don't have a 788, then you'll need movieslate, or some similar app on an I device and a 3.5mm to 5-pin lemo cable (it may need a resistor wired into it)..