I'm not sure if anybody else has given this any consideration, but I'm close to pulling the trigger on a second Mixpre (probably a second MixPre3) and I'm strongly considering buying a pair of these Tentacle Sync Timecode Generators...
https://www.bhphotovideo.com/bnh/controller/home?A=details&O=&Q=&ap=y&c3api=1876%2C%7Bcreative%7D%2C%7Bkeyword%7D&gclid=EAIaIQobChMInNjku4_L1wIVCbbACh3iOgw2EAQYASABEgIkd_D_BwE&is=REG&m=Y&sku=1327589These things are so economical and except for the non-locking connectors, the reviews are universally positive.
What will this do for me?
So neither the mixpre3 or mixpre6 have internal timecode but they accept timecode input via either the AuxIn or micro USB connectors. So I'd need two of these Tentacle Sync units to align the timecodes on both of my mixpres. The first Tentacle would be the master and set up from the computer (note that the manual says that once the clock is set, it maintains time even when the Tentacles are turned off, so theoretically you only need to set the clock on the master unit from the computer once). The second unit would then be jamsynched with the first so that both have their timecodes exactly synched. Then I'd connect each one of the Tentacles to each one of my Mixpre's...now they're getting the same timecode even though they aren't connected to each other with cables or bluetooth signals. With the timecodes aligned, both mixpre's will stay in sync (specs say within one frame for at least 24hours). Taboot, these Tentacles are powered from internal batteries that last over 40 hours! (If you REALLY want to get funky, say you want to share your recording with a buddy who's also using a recorder that accepts external timecode...you could jamsync even more Tentacles and have three or four recorders running off the same time code.)
My interest is locating one of my Mixpre's at the SBD and the other at my mics in the prime spot. No 100 foot long cables needed to run back to a single recorder to ensure that the tracks are aligned!
If you have a Mixpre10T with built in timecode, you'd only need one of the Tentacle synch unit. In that case, the 10T provides the master timecode and then you'd jamsync the Tentacle off of the 10T.
I'll still need to account for latency between my mics and the SBD signal, but that's a minor fix in post.
Of course, there are other possibilities as well. Say you have a mixpre6 and you need more tracks but you don't want to buy a 10T and might have a need for having the tracks on separate recorders (say you attend festivals and need two recorders to capture two stages). Just buy another mixpre3 or another mixpre6 and two of these Tentacles...it's less expensive than buying a 10T and gives you additional flexibility of being able to physically separate your tracks.
I wonder if anyone else has thought through this, or even tried it. Any thoughts to add? Any reason this wouldn't work as I've described above?