CDM-830 or CDM-831 for VHS transfer workflow?
 

I am intending to redo home VHS to DVD transfers that I did years ago. I have been researching this topic and now realize potential mistakes I may have made – for example using a JVC SR-MV40 and not turning on the TBC/DNR. Back then I’m not sure if I understood TBC/DNR. According to several posts on this forum, a broadcast TBC between VCR and capture device is not recommended with some exceptions. Too it seems most multisystem format converters (NTSC to PAL, etc.) only turn on TBC functionality during format conversion. Much of this old equipment seems to be plagued by flawed chips. In any event, here is my question: Using the JVC with TBC on, would it make sense to loop in on the JVC (VCR out, DVD in, both s-video) a CDM-830 and set the input and output to NTSC? Or would this only work with the CDM-831? The manual for both seems to suggest TBC is always on, but the wording for the 831 is more definitive. Hope this makes sense. Thanks.

With the JVC S-VHS combo DVD units, you cannot loop in a frame TBC. This is a weakness of this design. It was made for broadcaster S-VHS>DVD (dub), or just play/record VHS or DVD (not dub). It can work well with pristine VHS tapes, but not anything recorded from a crummy consumer camcorder (especially not VHS-C). This combo unit has a weak frame sync (not TBC) with the line TBC. I use one of these for my many hobby S-VHS SP tapes.

A CDM-830/831 is a Cypress, and is also plagued by the same bad chipset issue (aka "black" AVT-8710). I'm fairly certain that I've never seen a good-chip 831, and 830 can go either way. These are TBCs, so by definition the TBC is "always on".

Why would the black AVT-8710 still demand $$$$?
 

A black AVT-8710 unit is selling now on Ebay. Auction ends soon and latest bid is $455. Go figure.

Some people are completely clueless on what they're buying. By the time they figure out why the TBC is bad, it's often too late. This is the same reason that rackmount TBCs, and even non-TBCs (TBC routers, TBC remotes) sell. A fool and his money are soon parted?

Thankfully some folks come here, learn their error.
Others remain clueless, either accepting the errors, or spouting nonsense about why "TBCs are bad".

Research before buying, not after ... unless you're just 100% gambling, and don't mind losing money.

And that's also why I started to make hardware available in the marketplace. I'm the easy button, vetting hardware so others aren't duped or make expensive mistakes.