I just did an experiment feeding Audio-TC into my Tascam dr701d while formally jamming LTC from a BNC. Because folks do get laxed with these terms, I do mean jamming and then pulling the cable out for free run while recording uninterrupted audio. I let my recorder run for over 9 hours while it auto created 3 files, and then compared the file-TC with the recording.
It appears as though I am off by around a minute and 25 seconds by the 3rd file. Which is not very good performance for the Tascam dr-701d. You’d do much better with the new temperature infused crystal on the zoom F4 whereby folks are reporting drift in just a couple miliseconds at this scale all while remaining on the same video frame.
But here’s the thing, I figured the tentacle sync remembered my settings from the previous set-up, so I didn’t fix the frame rate. And I don’t think the tascam clock is conscious of frame rate; how could it be? I’ve brought the audio files into Tentacle Sync Studio, and that’s where I indicated the readings on the discrepancy between the Time Code sources. But the problem is that I don’t know if the File-TC has conformed to the Audio. It’s in yellow.
Is there any way to tell Tentacle Sync Studio in hindsight that I was using 29.97 fps ndf and have it recalibrate the difference? Maybe the performance on the Tascam would prove better. Or does the yellow dot on the File-TC indicate something other than what I’ve understood?
Okay-I now see the assumption in my experiment that would throw this off, but you may still find the subject useful. For one, the yellow vs green status indicates which source the conform will prioritize. Is that all there is to it?
As for the underlying assumption: the timecode fed to the Tentacle Sync was never from the internal clock of the Tascam, which can only read timecode. Therefore it’s to be expected that the Audio-TC was never correlated to the timecode on the Tascam as it continued to run. Which of course results in a much more straight forward conclusion that the only way you’d be able to free up a Tentacle Sync and use it for a different piece of equipment is
a) if you’re Jamming the Tentacle Sync from a source, i.e. something that can generate TC and not the other way around
b) that source continues to be the Master for the system. But that’s practically a given of a)