Fuji X-T3 , Mixpre-3 II and timecode help needed

[josdr]

After listening to very good advice from @IronFilm (keep the microphone close stoopid) and practicing some more in my amateur film-making endeavors I decided to upgrade to a mixpre-3 ii and run up to some trouble regarding timecode and resolve/premier editing that only the good people in eoshd can understand.

I am using the stereo out port of the mix-pre ii to send a timecode signal to the external microphone port of the X-T3 (with a simple small plug). Unfortunately the X-T3 does not seem able to sync (jam?)  to the X-T3 , so what I am getting from the x-t3 is a movie file with the audio track filled with the timecode signal only and from the mixpre I get a great sounding sound file.

Alas syncing audio and movie/timecode file is not that simple. It appears that there is no timecode track embedded in the mixpre. Originally I seem to have a movie file with audio-tc on channel one and the mix-pre file that does not have a audio-tc portion but rather a File-TC marker.

Once I import them into resolve 17, they are not able to sync together although I discovered that through resolve I can right click "Update timecode from audio track" on the movie file , and then both the mixpre and the movie file will sync dependent on the file-tc rather than the audio-tc ( I did not find a similar way to do this in premier pro)

My first question is :  Can I include an audio timecode channel in the mixpre output along with the recorded dialogue sound?  Is it advisable to do so? It only seems to record TC in the sound file header.

My second question is : Is this the best way to utilise timecode while using the X-T3 or is there a better way to go about it with what I have? The x-t3 can output timecode using its mini hdmi port (which I presume the mixpre can accept through its cam tc in mini hdmi port ) but I need the mini hdmi port of the X-T3 for my atomos shinobi. Or could I just sync the two devices once by this method and then disconnect the cable beween the two and  utilise the X-T3 hdmi for my monitor? Does timecode output have to be constantly connected from camera to recorder? 

Third question: Is there a way to update timecode from the audio track into a file track header in Premiere pro or am I stuck with Resolve for this.

 

Thanks in advance for every help you can give me and if any of my suppositions are erroneous or there are better ways of doing things with these two pieces of gear feel free to point it out.

Thank you!

 

 

 

[Cameramoto]

I am eager to know how you're going to resolve this because I'm a xt-3 user and would benefit from an external recorder.

Can't you set the x-t3 to running time code like the the hours of the day and then give it via hdmi to mix-pre 2 so that it's jammed to it and the disconnect them? Also, you could make a lame hdmi out from the shinobi to the mix-pre ii. I wonder if you would get the start recording marker sent in pass trough so the mix-pre ii starts recording at the same time? Even if it's a wire cluster fuck, it could be interesting. You might get a little delay from the hdmi loops but you could probably offset it in post.

 

also the good old sync via waveform could be a last resort since you send a perfect match in the camera. Last thing could be to buy a tentacle sync device. That would also give you the opportunity to be wire free for a sound guy to boom, etc.

[josdr]

3 hours ago, Cameramoto said:

I am eager to know how you're going to resolve this because I'm a xt-3 user and would benefit from an external recorder.

Can't you set the x-t3 to running time code like the the hours of the day and then give it via hdmi to mix-pre 2 so that it's jammed to it and the disconnect them? Also, you could make a lame hdmi out from the shinobi to the mix-pre ii. I wonder if you would get the start recording marker sent in pass trough so the mix-pre ii starts recording at the same time? Even if it's a wire cluster fuck, it could be interesting. You might get a little delay from the hdmi loops but you could probably offset it in post.

 

also the good old sync via waveform could be a last resort since you send a perfect match in the camera. Last thing could be to buy a tentacle sync device. That would also give you the opportunity to be wire free for a sound guy to boom, etc.

Hi, I am definitely NOT buying a tentacle sync, they are way overpriced for what they do and they make absolute no sense since the mixpre  and the X-T3 can output timecode. Waveform syncing works fine, I have been working it for years , but new toys and all I thought I would give timecode a go. I have no idea if timecode syncing via hdmi that will then be interrupted when I remove the x-t3 end will work or not. If that is the case then the camera will have to provide the timecode since it unfortunately does not having a setting to jam to an external timecode signal (I am unsure whether the x-t4 has such an option)  I am eagerly waiting @IronFilm 's response, he is the guru on such matters.

I am unsure on lame hdmi's etc, I dislike messes and they seem to let you down when you most need them to work. If you have any external recorder it will work fine with the X-T3. You can either feed it cleaner audio that comes from your recorder and is written on your main movie track , or just use the internal mic audio as a scratch file.  I presume that timecode will be a less user intensive solution.

The questions really have to do with how timecode is handled through the mixpre and editing software andalso  with the hardware combination of  the mixpre and the X-T3. The way I managed to do it now is too labour intensive, especially with the timecode being in two different places of the files I hope to use. Stick around, we will hopefully be schooled by more knowledgeable people on this matter. Thanks for the input

[KnightsFan]

4 hours ago, josdr said:

My first question is :  Can I include an audio timecode channel in the mixpre output along with the recorded dialogue sound?  Is it advisable to do so? It only seems to record TC in the sound file header.

Even if the MixPre can do this, it's not advisable. The purpose of timecode is tgetting that time stamp into metadata, and LTC on an audio track is just a workaround to do it. The only reason you'd want LTC in an audio track is if you A) can't put it in metadata, like on DSLR's, or B) need stretch and warp the audio to compensate for drift during the takes which I haven't ever personally seen anyone do, though it is technically possible.

4 hours ago, josdr said:

My second question is : Is this the best way to utilise timecode while using the X-T3 or is there a better way to go about it with what I have?

Wireless LTC is the simplest way in my opinion, but Imake sure you have scratch audio. My last big project with an XT3, I used a 3.5mm splitter, and ran LTC into one audio channel and used a $6 mic for scratch audio in the other. I used wireless lav transmitters to carry LTC from my Zoom F4 to the XT3.

5 hours ago, josdr said:

The x-t3 can output timecode using its mini hdmi port (which I presume the mixpre can accept through its cam tc in mini hdmi port ) but I need the mini hdmi port of the X-T3 for my atomos shinobi.

I am not sure if they are compatible, but it seems worth a test to me. See the answer below, jamming the timecode via HDMI might be a good combination of cheap/easy if the drift is acceptable for your work.

5 hours ago, josdr said:

Does timecode output have to be constantly connected from camera to recorder? 

If you are writing LTC into an audio track, then yes, it needs to be constantly connected.

If you are jamming the internal clock to an external source, then typically, no, once you disconnect the timecode source then the internal clock takes over from that same place. That means it is subject to drift once they are disconnected, and you would have to be sure that both are in free run. Definitely do some tests with the devices you own to see how much drift you're dealing with, whether the clock stops when the device is turned off, or other model-specific "gotchas."

5 hours ago, josdr said:

Third question: Is there a way to update timecode from the audio track into a file track header in Premiere pro or am I stuck with Resolve for this.

I'm not sure, I use Resolve exclusively. However it is possible to use 3rd party software to update the file's timecode metadata, which is what I do. I don't know of any ready-made solutions as I wrote the one that I use, but it's a simple ffmpeg command batched across all my files. In my opinion this is a better solution than doing it in your NLE, since the metadata will be ready for use in any software.

[josdr]

@KnightsFan thank you very much for a very detailed and thoughtful answer. From your writings I gather that the mini hdmi jamming test is worth a try, although it is unfortunate that the master timecode will come from the camera rather than the sound recorder . But that is a limitation that only fuji could bypass

Any way if that is feasible I can send much cleaner audio from the mixpre to the camera to use as scratch  and also have proper timecode to use. I will definitely try that.  Populating the movie audio with a timecode signal seemed the wrong way of going about things from the beginning,even to an amateur like me

 

[KnightsFan]

You're welcome!

14 minutes ago, josdr said:

Any way if that is feasible I can send much cleaner audio from the mixpre to the camera to use as scratch  and also have proper timecode to use.

You can send a mix from the MixPre to one channel on the XT3, and LTC to the other. Or potentially send a mix from the Mix Pre to the XT3 and HDMI TC the other direction.

15 minutes ago, josdr said:

Populating the movie audio with a timecode signal seemed the wrong way of going about things from the beginning,even to an amateur like me

I wouldn't say the wrong way. It's better than nothing, but it is a workaround compared to pro cameras that have proper timecode functionality. I would explore the HDMI side and see if that gets you where you need to be, and otherwise take some time to work out the workflow sending TC via audio. Once you have to down, it's not difficult, but there's so little information about it that it is indeed difficult to figure out how to make it work. Most people seem to be either pros and cameras with proper TC, or don't use it at all.

[josdr]

5 minutes ago, KnightsFan said:

You're welcome!

You can send a mix from the MixPre to one channel on the XT3, and LTC to the other. Or potentially send a mix from the Mix Pre to the XT3 and HDMI TC the other direction.

I presume I would need a Y splitter of sorts for that. The hdmi tc angel seems inetersting if it indeed works

5 minutes ago, KnightsFan said:

I wouldn't say the wrong way. It's better than nothing, but it is a workaround compared to pro cameras that have proper timecode functionality. I would explore the HDMI side and see if that gets you where you need to be, and otherwise take some time to work out the workflow sending TC via audio. Once you have to down, it's not difficult, but there's so little information about it that it is indeed difficult to figure out how to make it work. Most people seem to be either pros and cameras with proper TC, or don't use it at all.

You are spot on, there is no information at all. All I could find was tidbits by people that called the X-T3-4 a DSLR  and it was bad advice at that as well. I wish my camera could at least jam with teh timecode from the mixpre but Fuji has left this option out from both the X-T3/4. Probably wiring issues rather than a software one.

I suppose it is one of those instances that you are very near in accomplishing something but cant get over the last hurdle.  The mixpre was a good investment for an amateur (thanks to no social life because of the lock downs) and I am reluctant to buy a tentacle or whatever gizmo as well 🙂  .

It is funny because I though that the Fuji cameras and the mixpre recorders are a very logical and punching above its weight combination for cinematography on a "normal" budget and that there would be relevant info on this. Moreover the sound devices manual is not well written and leaves much to be desired in explaining things to someone that actually reads it but is not a sound professional.

[KnightsFan]

25 minutes ago, josdr said:

I presume I would need a Y splitter of sorts for that.

Yes, exactly.

25 minutes ago, josdr said:

I wish my camera could at least jam with teh timecode from the mixpre but Fuji has left this option out from both the X-T3/4.

It's very annoying, since it is such a small feature that is almost always missing from photo cameras, even ones marketed as hybrids. The GH5S is the only affordable hybrid I can think of with any real TC support. And like you say, dropping a few hundred on Tentacles is such a money drain. A nice, used mic or lens is less than a timecode system, which still only gets you audio LTC that you have to wrestle with in post! I'll never primarily use a camera that doesn't have an actual timecode input ever again, it's such a pain.

Depending on how DIY you are, you could build something yourself. I ended up making my own system with Arduinos synced over bluetooth to a cell phone app I made. It was cheap and works as well as a tentacle/other gizmo, but I probably put a hundred hours into making it so it was costly in that regard

I've been considering switching to a MixPre II myself. 32 bit would be useful when I'm recording by myself.

[josdr]

31 minutes ago, KnightsFan said:

Yes, exactly.

It's very annoying, since it is such a small feature that is almost always missing from photo cameras, even ones marketed as hybrids. The GH5S is the only affordable hybrid I can think of with any real TC support. And like you say, dropping a few hundred on Tentacles is such a money drain. A nice, used mic or lens is less than a timecode system, which still only gets you audio LTC that you have to wrestle with in post! I'll never primarily use a camera that doesn't have an actual timecode input ever again, it's such a pain.

It is VERY annoying giving money away when you have the primary function available and one part of the chain is not cooperative. The day has 24 hours, and we all try avoiding wrestling in post. Waveform matching has been good for me but when it lets you down it takes too much time to get a decent result.

Quote

Depending on how DIY you are, you could build something yourself. I ended up making my own system with Arduinos synced over bluetooth to a cell phone app I made. It was cheap and works as well as a tentacle/other gizmo, but I probably put a hundred hours into making it so it was costly in that regard

I've been considering switching to a MixPre II myself. 32 bit would be useful when I'm recording by myself.

The mixpre II is unbelievable after owning a tascam 60d ii. The sound is so clean you cannot believe it.  In a somewhat controlled environment the 24bit mode is all you need really, Its limiters are analogue as well and they work great.  I will test the 32 bit mode during the holidays.For run and gun and small crews that do not necessarily have great sound skills the 32 bit could be useful. I got it a couple of days ago so all my tests have been rudimentary . I believe it is well worth its money although I initially was very mindful of its price . I do not really think an independent film maker needs more and if he does need it, he will have the budget to hire a professional sound engineer anyways..  It is a great bit of kit. Very clean sound . The mke 600 sounds great and it made even the ntg2 sound better than I was used to. Before that, with the Tascam, izotope was my friend..

[IronFilm]

7 hours ago, josdr said:

After listening to very good advice from @IronFilm (keep the microphone close stoopid)

Yup, if you put the mic in the right place (at the right time) and kill any competing noise sources then you're most of the way to great sound!

But that's often easier said than done. Is like saying "all you need to do is put the camera in the right place (at the right time) with the correct exposure across the scene and you've got great cinematography!"
 

7 hours ago, josdr said:

I am using the stereo out port of the mix-pre ii to send a timecode signal to the external microphone port of the X-T3 (with a simple small plug). Unfortunately the X-T3 does not seem able to sync (jam?)  to the X-T3 , so what I am getting from the x-t3 is a movie file with the audio track filled with the timecode signal only and from the mixpre I get a great sounding sound file.

Aside from Panasonic's S1H and GH5S, there are zero hybrid mirrorless cameras which can accept timecode. 
The standard workaround hack is to drop the TC signal down from line level to mic level, and to write it to an audio track on the mirrorless camera. Then in post transform that into timecode for the files. Which once you've got this set up and done it before, is an easy workflow. 

But in your case you might have an even better option: an HDMI cord from your X-T3 to your MixPre3, then (assuming Fujifilm is sending out a record trigger that the MixPre3 can read) your MixPre will automatically start/stop with your X-T3 and already with the same timecode as is in the camera itself. 
 

3 hours ago, josdr said:

Hi, I am definitely NOT buying a tentacle sync, they are way overpriced for what they do and they make absolute no sense since the mixpre  and the X-T3 can output timecode.

From a recent historical context, the Tentacle Syncs are extremely small and extremely cheap compared to everything else that came before them! They were revolutionary game changers in their niche. 

And if you ever need your camera and field recorder to be disconnected from each other, then you must must must use a timecode box.

7 hours ago, josdr said:

Once I import them into resolve 17, they are not able to sync together although I discovered that through resolve I can right click "Update timecode from audio track" on the movie file , and then both the mixpre and the movie file will sync dependent on the file-tc rather than the audio-tc ( I did not find a similar way to do this in premier pro)

Yes,  "Update timecode from audio track" is exactly what you should do. 
Or use the supplied software that came with the Tentacle. 
(unfortunately Premiere is still stuck in the dark ages, even the dinosaur Avid has this feature)

[IronFilm]

8 hours ago, josdr said:

My first question is :  Can I include an audio timecode channel in the mixpre output along with the recorded dialogue sound?  Is it advisable to do so? It only seems to record TC in the sound file header.

Yes, you could easily write both a AuxLTC and a scratch track if you were using a Tentacle Sync (yet another benefit of them). Otherwise, you'd need to create a custom cable (as I doubt the MixPre has this feature built in, but it would be a good feature request to send to Sound Devices!).
And yes, it is advisable to do so as then the scratch track is your back up safety net for syncing. 

8 hours ago, josdr said:

My second question is : Is this the best way to utilise timecode while using the X-T3 or is there a better way to go about it with what I have? The x-t3 can output timecode using its mini hdmi port (which I presume the mixpre can accept through its cam tc in mini hdmi port ) but I need the mini hdmi port of the X-T3 for my atomos shinobi. Or could I just sync the two devices once by this method and then disconnect the cable beween the two and  utilise the X-T3 hdmi for my monitor? Does timecode output have to be constantly connected from camera to recorder? 

No, don't do this! They will drift apart. (cameras are universally hopeless at holding TC, with the rare exception of ARRI/Panavision sometimes, but even those I would rather not trust as they've proven to not always be perfect)
Sadly the MixPre has no HDMI pass through (this is what the Tascam DR701D got right! Even if otherwise Tascam is quite irrelevant now in 2021, for goodness sake where are their modern day updates to their line up????). And sadly the Atomos Shinobi lacks an HDMI output (although, it might strip TC off if it did have one, you'd have to test that it doesn't). 

  

53 minutes ago, KnightsFan said:

A nice, used mic or lens is less than a timecode system

I don't know of any used mic that is cheaper than a used Tentacle Sync which I'd use as a primary boom. They're not even close in price, because that Tentacle is so cheap. 

[IronFilm]

56 minutes ago, KnightsFan said:

I'll never primarily use a camera that doesn't have an actual timecode input ever again

We can thank the Netflix gods for making 2020 the year which every cinema camera (even the entry level ones) got released with timecode functionality! 

 

26 minutes ago, josdr said:

The mixpre II is unbelievable after owning a tascam 60d ii. The sound is so clean you cannot believe it. 

Yup, and I'm a fan of the DR60D! (I momentarily had a DR60Dmk1 before I upgraded to a Sound Devices 552 fairly quickly, and the DR60Dmk2 is even a bit better than the mk1)
I think at that price point, the Tascam DR60D is the best there is. (which is another reason why I'm so mad at Tascam for falling behind the times and not releasing anything in recent years!! As they've shown so much potential in the past)

Yet even so, it is very hard to recommend strongly the Tascam DR60Dmk2, when for only a little bit more money you can get a Zoom F6/F4/F8 or Sound Devices MixPre3/6 which are going to be so so so so sooooo much better. 

[KnightsFan]

@josdr I had a DR-60D II before, so I believe that. I can live without 32 bit, but it's the top of my "nice to haves," particularly when effects and I'm already holding a mic and performing sounds all at once.

13 minutes ago, IronFilm said:

I don't know of any used mic that is cheaper than a used Tentacle Sync which I'd use as a primary boom. They're not even close in price, because that Tentacle is so cheap.

I found my AKG CK93 for less than $200, just shy of a new Tentacle Sync E, and that's my primary mic. My first mic, the Rode NTG1, was about $130 if I recall. Both of which were in my opinion better investments that a timecode system, especially since you need minimum two tentacles.

[IronFilm]

1 hour ago, KnightsFan said:

I found my AKG CK93 for less than $200, just shy of a new Tentacle Sync E

Doing secondhand vs new isn't a fair comparison. 
Secondhand Tentacle Sync could be found for as cheap as roughly US$100ish, perhaps $150 max. 

1 hour ago, KnightsFan said:

My first mic, the Rode NTG1, was about $130 if I recall

NTG1 is a weak choice
The Canon Rebel DSLR of the audio world. 

1 hour ago, KnightsFan said:

Both of which were in my opinion better investments that a timecode system, especially since you need minimum two tentacles.

Both mics and TC boxes are needed on a film shoot. 
And you can get away with just one Tentacle. (the Zoom F Series and MixPre Gen2 hold TC by themselves)

[KnightsFan]

4 hours ago, IronFilm said:

Doing secondhand vs new isn't a fair comparison. 
Secondhand Tentacle Sync could be found for as cheap as roughly US$100ish, perhaps $150 max. 

Maybe I look at the wrong time, but I've looked every now and then and I have yet to see any on eBay below $200 in the US.

4 hours ago, IronFilm said:

Both mics and TC boxes are needed on a film shoot. 
And you can get away with just one Tentacle. (the Zoom F Series and MixPre Gen2 hold TC by themselves)

You can sync without TC, it just takes more effort, as the OP and many of us did for years, especially since the major NLE's can sync from waveform. It's a lot of money for something that makes a small improvement to smaller projects.

You are talking about jam syncing, in that case, right? You can't use a single tentacle to send constant TC between two devices--can you?

[josdr]

11 hours ago, IronFilm said:

 

Yet even so, it is very hard to recommend strongly the Tascam DR60Dmk2, when for only a little bit more money you can get a Zoom F6/F4/F8 or Sound Devices MixPre3/6 which are going to be so so so so sooooo much better. 

Yes they are! although I could not find a zoom f4 no matter how hard I tried. But I am every happy with the mixer and I have barely scratched the surface yet.

 

Thank you for all your advice . I will not answer piecemeal since I ingested all your various answers in the different posts 🙂 . Thank you and Merry Christmas and a Happy  New Year

[josdr]

6 hours ago, KnightsFan said:

Maybe I look at the wrong time, but I've looked every now and then and I have yet to see any on eBay below $200 in the US.

You can sync without TC, it just takes more effort, as the OP and many of us did for years, especially since the major NLE's can sync from waveform. It's a lot of money for something that makes a small improvement to smaller projects.

You are talking about jam syncing, in that case, right? You can't use a single tentacle to send constant TC between two devices--can you?

Merry Christmas and Happy new year !  The Tentacles are 200 euros plus vat and unavailable for months. I think you can jam sync with a camera  and then use the jammed tentacle with  a recorder that has timecode  but don't quote me on that. If you need two that's 400 plus vat, you might as well save up to get a cine camera. They may be "cheap" fro professionals but not that cheap for indy film making

[IronFilm]

7 hours ago, KnightsFan said:

Maybe I look at the wrong time, but I've looked every now and then and I have yet to see any on eBay below $200 in the US.

You might need to wait a little while to see it on eBay, it helps to keep looking across all the right places (jwsound/reverb/facebook/bblist/etc) and not just in the one place. 

1 hour ago, josdr said:

Yes they are! although I could not find a zoom f4 no matter how hard I tried. But I am every happy with the mixer and I have barely scratched the surface yet.

Yeah, I'm gutted they discontinued the F4 and didn't bring out a Zoom F4n. 
Somehow they think the Zoom F6 is the appropriate replacement, which is absolutely not true!

7 hours ago, KnightsFan said:

You are talking about jam syncing, in that case, right? You can't use a single tentacle to send constant TC between two devices--can you?

You only need the one (per camera), because any professional (and even semi-professional these days) field recorder will hold timecode accurately by itself. 

1 hour ago, josdr said:

If you need two that's 400 plus vat, you might as well save up to get a cine camera. They may be "cheap" fro professionals but not that cheap for indy film making

No, you only "need" at minimum the one (per camera. And using a "cine camera" won't save you from the need of one timecode box per camera, that's still required). Although yes, keeping an additional spare as master is handy. (but far from essential for low budget indie filmmaking)
And yes, I do think this is cheap even in the context of indie filmmaking, just look at how much is spent on lights / camera / lenses / tripod / etc etc

 

[josdr]

3 hours ago, IronFilm said:

You might need to wait a little while to see it on eBay, it helps to keep looking across all the right places (jwsound/reverb/facebook/bblist/etc) and not just in the one place. 

Yeah, I'm gutted they discontinued the F4 and didn't bring out a Zoom F4n. 
Somehow they think the Zoom F6 is the appropriate replacement, which is absolutely not true!

They really lost a lot of sales there. An F4n would have been a very easy choice. The zoom F6 is a mess ergonomically and at that price point you will buy a mixpre. Just came back after test recording external sounds.. Unbelievable. I recorded birds chirping like they were next to me (with negligible ancillary noise), waves from about 10 meters away and a stream about 5 meters away like I was next to it. Unbelievable clarity in all recordings. I tried to use the 32 bit float function just to have an idea (starting my car with full gain ), but you know what? The 24 bit mode plus analogue limiters is so good that you must be a total dick in getting an unusable recording. 

3 hours ago, IronFilm said:

You only need the one (per camera), because any professional (and even semi-professional these days) field recorder will hold timecode accurately by itself. 

No, you only "need" at minimum the one (per camera. And using a "cine camera" won't save you from the need of one timecode box per camera, that's still required). Although yes, keeping an additional spare as master is handy. (but far from essential for low budget indie filmmaking)
And yes, I do think this is cheap even in the context of indie filmmaking, just look at how much is spent on lights / camera / lenses / tripod / etc etc

 

Cant say you are wrong there. "Cheap" redefines itself quite a lot as you progress with your film making lol.  So how would a tentacle be used with a mixpre and an X-T3 or any other mirrorless for that matter, if I cannot jam them together?

The camera cannot be synced to the mixpre (no timecode input), so do you sync the tentacle to the mixpre output timecode and then jack the tentacle into the camera?

[IronFilm]

56 minutes ago, josdr said:

They really lost a lot of sales there. An F4n would have been a very easy choice. The zoom F6 is a mess ergonomically and at that price point you will buy a mixpre.

I 100% agreed with you right up until to the last moment, as I'd still take a Zoom F6 over a MixPre3mk2 for the same price. (slightly more actually)

Then again if you never need more than 3x channels, the edge might swing back to the MixPre3mk2 again. 

56 minutes ago, josdr said:

So how would a tentacle be used with a mixpre and an X-T3 or any other mirrorless for that matter, if I cannot jam them together?

Eh? You can jam the MixPre Gen2 / Tentacle to each other.
Then you attach a Tentacle to the X-T3, and leave it there for the entire shoot. 
Easy. Done. 
(then in post, use Tentacle's own software for AuxLTC, or a NLE with this already built in such as AVID or DaVinci Resolve)