Using s-video Y-splitter for recording?
 

I may end up using a VCR in passthrough mode to correct any jitter in captures. But from my understanding, that should be done judiciously, and only on captures that show problems. I don't want to capture a 1-hr tape (captured without passthrough), view it, then have to do it again. So, is the idea below likely to work, using identical capture devices, software and computers. The computers are identical physically, and the OS will be identical clones. For the moment, let's assume the captures are only different in the jittery area.

1. Buy an S-Video splitter
2. Connect that to the output of the VCR.
3. One side of the Y goes to Capture Device #1; the other side goes to the passthrough VCR and then to capture Device #2
4. Save to ProRes 422HQ
5. Import both into Premiere, then layer and align on the timeline. Turn off Capture #2 so it is not visible.
   
6. If there is no obvious jitters on Capture #1, I delete Capture #2.
7. If there are jitters, then where the jitter occurs, I crop to that section of Capture #2 and make it visible. Result should be that I end up with the best from both transfers in one go.

Any reason why the above won't work?

Be careful about splitting low impedance line signal, it gets weaker and noisier, Unless you have a powered active proc amp with 2 or more outputs don't even think about it.

As noted above a simple splitter per the link can cause issues and a significant signal weakening if both inputs are 75 ohm, as is typical for video. If you intent to send the same video signal to several different inputs you should use a distribution amp, or insure that only one input (whether composite or s-video) is 75 ohm and the rest are high impedance.

Some video devices may have multiple outputs but that is not common. On the other hand, Audio is generally easier to split with a Y cable and much more forgiving.

Radio Design Labs FP-SVDA4 1X4 S-Video Distribution Amplifier, available on Amazon for ~$200 in one, but I have no experience with it.
https://amzn.to/3P3EDxf

As others have said, you don't want to just split the signal passively - you'd want to use a distribution amplifier.

Extron is a pretty well known brand and they have multiple models that can give you additional S-Video outputs.

For your needs, the Extron MDA 3SV is probably fine. Those can be had on ebay for $30 shipped or so. They do require power adapters though and most of the ones on ebay are missing that. Any 12V 1A adapter should be fine if you either direct solder to the internal boards or buy an extron adapter for it.

Do you mean use a DVD recorder in pass through mode? Exactly what all hardware are you wanting to use in this test? What are the models?

Thanks for the suggestions. I used incorrect terminology when I said VCR and passthrough. DVD recorder and passthrough.

I was particularly keen on the distribution amplifiers. I had searched for amplifiers, but didn't come across the two mentioned. Wrong search terms.

The Exton looks very promising. Too bad I live in a technically backward country where most of the devices for capturing VHS tapes aren't readily available. Someone in the US could pick up an Exton for less than $50, two day delivery. It would cost me well above $100 and several weeks waiting. In Australia we're tops for sunshine, iron ore, coal, and dug up things; not so good in these technical things. Great place to live though, especially Tasmania.

Anyway, the equipment to be used is still a work in progress. Matthew in Melbourne, who has been helping me out, has most of the capture devices and software commonly mentioned on this website, and is still accumulating. His 40 captures will make up the bulk of the test results. But my equipment runs to this:

• JVC HR-S6960
• several Macs running under OSX 10.9.5 and 10.6.8, running VideoGlide
• Hauppauge HD PVR2, running under Windows 10 on a laptop borrowed from a friend, using Hauppauge Capture (we can't get VirtualDub to work)

Items to be purchased in the next few weeks:

• Kaiser Baas capture device
• ATI 600 clone
• Panasonic DMR ES15
• S-Video Y-splitter (if I decide to go ahead with that method)

That captures card is newer and meant for gaming. It probably isn’t compatible with virtualdub. That’s a good reason to ditch the card.

I don’t think anyone here is wondering if an es-15 is better than nothing.

Pretty much no one here is wondering if Haupage Capture is better software than Virtualdub. I don’t see anyone recommending that software for VHS capture. Virtualdub was created for this task. You have to be able to view your dropped and inserted frames counter. There’s a lot of different setting you can do with virtualdub that you can’t with your software. The road to getting good captures is already long without taking a big unnecessary detour. It’s your time and your money though so your choice. It’s just not a needed test. You could chat with tech support and they would probably tell you that’s not what the software is meant for.