Weapon, Audio, Timecode, and Zoom F8?

[Matthew J]

I am having issues with my Weapon Mg and simultaneously feeding audio and timecode to it. The issue is, when I have my weapon hooked up to the F8 for timecode and also for scratch audio (via either the minijack sub 1/2 or headphone jack) I get timecode audio faintly in the audio tracks on my Weapon w/basic expander. I have tried different timecode cables, audio cables, and running the Weapon of different power sources. Yet, no matter what I do, if I have both timecode and audio hooked up to the Weapon, I get the timecode sound in the background of my audio tracks. Right now I am trying to figure out if it's my weapon or the F8. So if anyone has an F8, could they try hooking it up, both timecode and audio, to see if they have the same issue?
Thanks.

 

[Michael Tiemann]

First off, I presume the problem you are reporting is with the audio files recorded on the Weapon, not those recorded on the F8. If timecode is bleeding into the F8, you have serious problems. If you are relying on Weapon audio to be more than scratch audio for your F8, you have serious problems. If you only use the Weapon for scratch audio and the F8 for "real" audio, and there's no bleed found on the F8 channels recording "real" sound (from actual microphones you placed), then you don't have a real problem.

That said, if you want more from your Mg audio...Timecode is a noisy signal and will bleed into unbalanced audio cables. The Base I/O module only has unbalanced audio, so you either need to convert to balanced before the audio cables "see" the timecode coming over the LEMO cable or you need to null out the timecode in post by feeding an inverted timecode signal (appropriately attenuated and aligned in time) to cancel out the bleed that was recorded.

It might be possible to treat the F8 as one tangent of a circle and the Weapon as an opposite tangent of a circle, sending the audio signal around one size of the circle and the timecode around the other. You should notice a difference between a cabling strategy that has the two cables running parallel and another that has the two cables never intersecting at all (and at all times being no closer than are the actual jacks on the respective piece of hardware).

But again, if you have an external recording like the F8, you should only be relying on the Weapon for scratch audio, not anything you would then feed to production.

 

[Todd T]

Is there a specific reason for not jam-syncing the timecode and then disconnecting the F8 from the Weapon?

 

[Matthew J]

Is there a specific reason for not jam-syncing the timecode and then disconnecting the F8 from the Weapon?

For interviews I stick the F8 on an am on the camera, so it's nice to just leave timecode plugged in and not worry about drift or any other issues between powering down, etc.

While I would not normally use the audio from the camera, it is nice to have a useable backup in case something happens with the recorder...like I had happen last month. If you can easily record clean audio on the camera audio tracks in addition to the recorder, why not?

 

[Roger Singh]

You're still going to get drift I believe. It just refers to the F8 timecode at the first frame of recording. You need a tri-level sync box to send both timecode and genlock to avoid drift.

 

[Matthew J]

You're still going to get drift I believe. It just refers to the F8 timecode at the first frame of recording. You need a tri-level sync box to send both timecode and genlock to avoid drift.

I haven't had my Epic or Weapon drift even a frame over 4 hours of running. Plus, I am not doing 4 hour takes, so it would be getting timecode every 30 minutes at worse. The issue is when I shut off the Camera or Zoom, that's when drift can occur (such as a battery swap.)

 

[Marc Wielage]

I haven't had my Epic or Weapon drift even a frame over 4 hours of running. Plus, I am not doing 4 hour takes, so it would be getting timecode every 30 minutes at worse. The issue is when I shut off the Camera or Zoom, that's when drift can occur (such as a battery swap.)

The solution for that is to have a tri-level sync box on the camera, one that jams to the audio recorder timecode. But the Zooms are known to lose timecode accuracy when shut down, so I wouldn't trust them for this purpose. Even with a Sound Devices recorder, I don't ever, ever shut down the machine all day long unless there's a company move and I have the ability to rejam. And I'll still rejam on a meal break just out of paranoia and tradition.

One of the things you pay for with a Sound Devices recorder is the built-in Ambient timecode generators, which are extremely accurate and should not drift provided the internal battery is good. Another plus is that the Sound Devices recorders always start their sound files on a :00 frame, which is helpful for editorial. I have gone 6-7 hours without drift on Sound Devices recorders and Denecke SB-T sync boxes, but I never pushed it much beyond that. I don't trust the built-in timecode generators in any camera, and that includes Alexa, Blackmagic, Canon, Red, Sony, or anything.

 

[Stacey Spears]

I recently purchased an audio kit to go with my Red. I ended up with the SD633, Schoeps CMIT5U, Ambient TC slate and Ambient Master Lockit. (ML) The ML is connected to the SD633. The TC slate jams from the ML over the ACN network. The OMOD has Ambient in as well along with genlock. So it also jams from the ML over ACN. Everything is in sync. I was on the fence for a bit on spending the extra money on the ML vs. the tiny lockit. The ML has other benefits I was not aware of at the time with their web interface where I can see the other devices on the ACN network, such as the slate and OMOD. I can also export metadata, which includes the audio clip names. Its great!

 

[Marc Wielage]

I recently purchased an audio kit to go with my Red. I ended up with the SD633, Schoeps CMIT5U, Ambient TC slate and Ambient Master Lockit.

The Ambient timecode stuff is first rate and very reliable. I prefer Denecke because I know the people that run the company in the LA area, but this is a "Mercedes vs. BMW" comparison -- you can't go wrong with either.

 

[Stacey Spears]

I have an SB-T that I used fo 3D. I would have stayed with Denecke, but OMOD uses ACN, so I switched.

 

[Marc Wielage]

One thing I'll say for Ambient: they do give you the adjustments to make very precise calibration in the field, provided you have their alignment accessory.