Is it possible for a Tentacle to change itself from line to mic in any circumstance?

4.73K viewsHardware

Before shooting I checked both my tentacles were on line level and had accurate code. I then checked the Alexa Mini and the Sound Devices to make sure they both were receiving accurate code.

We’ve gotten back into the studio after shooting all day and discovered that one of the units is now set to mic and that some of the footage towards the latter half of the day is a few frames out.

So, I checked the timecode myself and know that I set them correctly. I then re-checked that both devices were receiving it accurately yet sometime during the day the Tentacle switched to mic and no longer sent accurate TC? Is what I’m suggested possible or has happened in any other circumstance?

This is the first time I’ve encountered this issue.


Tentacle has an Auto-Mic detection feature. If Tentacle has been set to LINEĀ Level it will switch its output to MICĀ if a phantom or plugin-power has been detected. This is normally only the case on microphone inputs and works very well. It will also switch itself back to LINE level if the phantom power has been gone.

So the only case where this could happen is that Tentacle detected a DC-voltage on the timecode output. But there should be not DC-voltage on a LEMO 5 Pin on an Alexa Mini. We have tested Tentacle with any kind of ARRI camera including the Mini with no issues.

So maybe it is just a faulty cable? Also, if you don’t trust the Auto-Mic function, you can just turn it off in the setup app as Fokke mentioned.

Hope that helps!



Do you have “Auto Mic Level Enable” turned on?