You don't need a TBC in 2023

[dellsam34]

Whatever you do, don't mess with the alignment until the pinch roller is replaced and the tape path is cleaned.

[Marshalleq]

Since it's from vcrshop I would rather contact them about the split pinch roller and possibly misaligned audio head before messing with it on your own.

I will contact them, but the reality is to send it from New Zealand to the Netherlands is likely not to be worth the cost. Also the irony that if I hadn't done this myself, I would never have known anyway...

[dellsam34]

They can just send you a pinch roller or buy one online, I've already showed you how to replace it.

[Marshalleq]

Yep, I've messaged them now and explained it all, asking if they have one. Had a quick look online last night - JVC seems to be less common, but I'm hoping they're fairly generic, will see about getting one after work. I'm also going to play a tape through with the cover off to see if there's any obvious slipping, one theory I have is some of these older tapes may not be as smooth to pull through - that's certainly what I've seen when de-moulding some of them. That in turn I assume would be impacted by the pinch roller but could be wrong.

[oln]

The mechanism was used by JVC for a few years and it's possible the part was cross-compatible with the older/newer mech too, not sure. It shouldn't be too hard to source a used pinch roller from a cheaper lower end model at the very least if they aren't able to send you a new one.

[Marshalleq]

Yeah, JVC is not a common brand of VCR in my country. So eBay is where it's at and that equals a lot of dollars - their shipping cost is outrageous to here. I probably should have gotten a Panasonic, but JVC seemed like the better model for S-VHS. Anyway, I'm sure I'll find something. Thanks for your help.

[Marshalleq]

So two updates:

1 - If I constantly clean that pinch roller, the problem goes away. Tells me it's gone hard and shiny and needs to be replaced. So that lines up.
2 - I don't think I'm going to try get the roller off until I speak to my electronics friend. I had a quick go prying it off, after reading how to do it online, and I think I'm going to damage the clip - which unlike the pinch roller - I'm sure is not replaceable, so I don't wish to damage that. I probably need to find a video to see it being done.

Otherwise, there has been another problem surface, which is that now the the 10 second cyclic dropout has gone away, I'm getting freezes in the output from the VCR. I'm starting to wish I'd just got something off eBay, but vcrshop was recommended to me from this site so I went that route. Such is the fun of buying end of life equipment I guess.

No word from VCRShop on the pinch roller yet - but different timezone - they've been really responsive so far so probably overnight.

I am wondering if I need to buy another S-VHS player at this point.

[Marshalleq]

So they're going to send me another pinch roller. The VCR took maybe 2 months to turn up, the remote is also pending and now the pinch roller. I watched a video of how to take it out and then tried it. It won't budge. I'm not really very happy. This should have been vetted more than this. I do have another good vcr with what looks like the same pinch roller in it, but I'm reluctant because I'm worried I'll break that one only to find that this one still doesn't work properly. This is one of those nights you go to bed on a negative, which I don't like. Oh well.

Here's a closer up picture of the pinch roller and it's retaining ring. From what I've seen the retaining ring is more like a tube that just pushes over the top. I've tried to sort of pry it a bit with a small screwdriver, I've also tried to sort of lift it up by lifting the whole pinch roller up, wriggling it side to side and various combinations. I didn't manage to get it to slide up even 1mm, but it is undoubtedly denting the retaining ring etc. I'm wondering about some needle nose pliers, but interested what do you guys use to do this?

Thanks.


[Attachment 73736 - Click to enlarge]

[Alwyn]

but vcrshop was recommended to me from this site so I went that route.

I have suggested VCRShop, obviously naively thinking that it would do a decent job at checking before sale. If that hasn't happened, I'd give it a rocket. Maybe it's website has a tiny disclaimer somewhere that says "we just on-sell any random junk we get from ebay/craigslist/the local thrift shop for a profit".

Life's hard enough as it is without a company with that name doing dodgy deals on VCRs.

[dellsam34]

You will need a small needle plyer, grab the retaining ring with the tips of the needle plyer and gently twist left and right while pulling up, I've done so many and never had a problem. If you don't feel comfortable find a repair shop and pay them to do it for you.
If you want to buy one online just measure the outer and inner diameter (shaft thickness), most VCR's use the same diameter but there are exceptions.

[Marshalleq]

Perfect, I wasn't doing it that way so thanks for that - that makes sense and sounds easy enough, I'll give it another go. Good to hear we can get replacements!

[Barrythecrab]

Is this still a TBC conversation?

[dellsam34]

It is about the issue the OP is having, He himself admitted it's the clickbait headline, So this thread is not about TBC.

[lordsmurf]

"we just on-sell any random junk we get from ebay/craigslist/the local thrift shop for a profit".
Life's hard enough as it is without a company with that name doing dodgy deals on VCRs.

No, I don't think that's the case here. Rubber parts like that can crack in transit, I've seen it before. You have to remember what all climates it get subjected to in transit.

[Marshalleq]

You will need a small needle plyer, grab the retaining ring with the tips of the needle plyer and gently twist left and right while pulling up, I've done so many and never had a problem. If you don't feel comfortable find a repair shop and pay them to do it for you.
If you want to buy one online just measure the outer and inner diameter (shaft thickness), most VCR's use the same diameter but there are exceptions.

Hi, when you've done it do your pliers get right down to the main clip shaft, or do they just fit over the first part? I'm trying as a test on one of my other VHS machines I've purchased for this exercise and I only get to the first part and I still can't get it to budge, I tried squeezing a bit harder and the clip started bending quite majorly actually - I just can't grab onto it without destroying it. I can't turn it because I can't grab onto it strong enough, it doesn't budge. So do I need even smaller pliers? I feel this is all that's between me and VHS happiness at the moment.


[Attachment 73744 - Click to enlarge]

[dellsam34]

You need a small needle plyer, Worst comes to worst, if you are careful you can pry the whole thing out from underneath the pinche roller with a flat tool but try not to bend the pinch roller arm, If that scares you, remove the pinch roller arm and work outside the VCR, Otherwise just find someone more skilled than you are. I really hate to give advise online because I once told one guy to put a dab of silicon and he squeezed half the tube and try to blame it on me.

[Marshalleq]

Haha, yeah I understand about the advice part. I was just trying to figure out if your pliers were smaller than mine and went more down into the shaft. I can only get mine around the top lip of it which is clearly less effective of the two. Presently this is what I think the issue is. I've already tried prying it from underneath and that didn't work either - but perhaps I need a slimmer longer tool or something. This on two VCR's now. I must just be using a method that's not quite right. In New Zealand there are no longer electronics repair shops unfortunately, everything is throw away. I do have a good friend that's an electronics engineer, he may have a tool, people I know that do other mechanical things like restoring old engines and such, so I'll find someone, but obviously this is way less easy than doing it myself and will likely add weeks or months to the timeline. Such a silly little thing to stop me!

EDIT: I just bought an expensive and smaller set of pliers. All that's happening is it's damaging the clip. So I don't know how anyone else would do this, but it seems I'm incapable of this basic thing. I'm reluctant to remove the whole mechanism, but perhaps that's what is required so I can pry it from the bottom.

[Marshalleq]

Ok done it. I ended up pulling it out the whole thing with my fingers! Then swapped it with the other VCR. And it had four more splits on the bottom of it so definitely needs a new one. So far the swapped one is tracking better I think. So now I'm playing around with the Datavideo DVK-100 I got. Which seems to do nothing much but add a bit of noise, but too early to tell. Top of my list is to figure out if I can reduce the noise, maybe remove the fan, the caps look good, but will get them tested.

My current belief is that the ADVC-100 does seem to be doing something to tidy up the picture and audio sync and it's making the DVK-100 nearly redundant. I know this is not what the accepted belief is, so I plan to do some examples with each device. I did see the DVK-100 tidy up some of the problems caused by the faulty pinch roller, so I know it's working, but now that that's replaced, I'm basically seeing no difference yet (other than the noise that is).

Thanks for all your help everyone.

[Marshalleq]

The DVK-100 does fix this - which I assumed was a setting in the VCR that I can't change without the remote. Not sure what it is yet, but it always went away when I started playing a tape anyway, anyone know? There's still a bit of ghosting in it though which I'm wondering about as it's coming out in all the tapes. ive' got the service manual now, so perhaps something in there.


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[dellsam34]

Don't rely on the VCR's menu screen, It is never in the right video format, Always use the tape active contents. Also try to capture straight from the VCR's S-Video out, add devices only when the need arises.

[Marshalleq]

I just thought it was interesting that it did that. The menu screen comes right when playing back anyway, without the DVK-100. But the DVK-100 makes it go away when in the menu screen. I find it fascinating that it also fixes audio drop outs when the audio doesn't pass through it. I'm wondering if that's just the ADVC-100 sort of dropping it out because it's out of sync, then the DVK somehow boosts the line signal and that sorts it back out. No idea. I'm doing S-VHS player, DVK-100, ADVC-100 at present. I'll drop the DVK100 out of it if it's no use, but playing around for now.

[dellsam34]

I would drop the ADVC-100 first.

[Marshalleq]

From what I'm seeing, I think the ADVC-100 is going to fix the audio drop outs, which is counter intuitive, nevertheless that's what I'm seeing. One more test to check that. I've also found a blu ray version of the DMR ES-15 which might be interesting as I suspect it has a far better codec in it and also specifically lists a TBC. But that's sort of off topic so will post somewhere else.

[Marshalleq]

I'd just like to say a heartfelt thank you to all of those on here that have helped me and to those that make the site what it is. I don't really know why I came to this site - I think perhaps I searched on ADVC-100 and led my way here. After replacing the pinch roller with the one from my other unit, I can't believe the difference this SVHS player is making to the tapes I have. Text that wasn't visible is now visible, faces that were washed out are now detailed right down to freckles, parts of tapes that had huge wriggly black lines and parts that were completely black with noise and no audio have become completely perfect, and one of the most important, the shimmering effect that causes everything to be not straight is gone. The footage is so good, that using AI upscaling actually works on it now, where it didn't before. I had no idea it could improve this much.

I'm not sure yet about a frame TBC, I can see my DVK-100 has some bad caps, so will see what it does once that's fixed. I've also purchased a Magewell XI204XE Dual DVI + Quad CVBS which has an S-VIDEO input and I hope to get some quality improvement - I think it supports a bigger colour space, if not, I will try again! The reason I've decided this is important, is after reading about 4:2:0 (what I believe I have with the ADVC-100 and 4:2:2, there is actually quite a quality loss around the edges of subjects due to the sampling used - now that I understand that while this is to do with colour, it effectively isn't just to do with colour. I can see this in countless videos, I have to figure out what an S-VHS is ultimately sending out too - but for faithful edge reproduction alone, it now seems that ultimately you want 4:4:4 though most will not notice the difference between that and 4:2:2. Also, I can see it is more of a problem on lower resolution sources than higher resolution sources. Who would have guessed!

There are a couple of areas for some reason are worse on the new player, I'm really not sure why - but they're relatively minor by comparison and perhaps a frame TBC will fix them. I have one NTSC tape that I will need to do something different with, that's a problem as I'll need a proper player or to trust someone to horse trade a PAL copy for an NTSC copy I think! But all in all, I'm very grateful. Thanks very much everyone for the help, already our family memories have gone from 'did we really used to watch such bad quality recordings?' - to being quite watchable by modern standards.

Thankyou!

Marshalleq.

[dellsam34]

I'm not aware of any SD analog capture device that can sample at 4:4:4, If you set the capture software to 4:4:4, it will just be up sampling on the fly, bloating the file size with no gain in quality. Frame TBC cannot improve picture quality, it only fixes frame timing.

[Marshalleq]

Good call out about 4:4:4. With regards to frame TBC's does not incorrect frame timing cause picture glitches? Otherwise why would you use a frame tbc?

[dellsam34]

Theorically, No. and I say this because most frame TBC's are built in proc amp that can change chroma and luma parameters/levels, therefore they can change the visual video frame but not to the extent of fixing glitches and problems related to video signal, Their main function first is to fix frame timing signal (VBI), Second, if available, they can adjust color saturation, hue, luminance level ...etc.

[Marshalleq]

So that's interesting. I had assumed and possibly seen in once instance that frame timing issues caused visual glitches. An external TBC get's high credit around here, but from what you're saying it's fairly pointless. I mean I get you're describing what it does technically and as such I'm having to guess what the benefit is. But it doesn't seem like there's much benefit from what you're saying?

[dellsam34]

Correct, assuming your tapes are in good condition, a good VCR, a good capture device and a computer system adequate for the task. If you have problems such as frame jump, frame roll, blank frames, audio out of sync with video, a frame TBC may come handy, Although not all frame TBC's are equal and they don't always fix all the mentioned problems.

[Bwaak]

@Marshalleq, "Frame TBC" is not a standard term. Those who use this term usually mean "Frame Synchronizer", which, as dellsam34 correctly notes, aligns V-sync pulses either with another video (proper Frame Synchronizer mode) or with built-in clock ("Frame TBC" mode) just like regular or "Line TBC" does, which aligns H-sync pulses pulse generator. Yes, without V-sync properly timed you can see picture roll and other defects caused by the loss of synchronization.

This is a good short video that shows how it works instead of proclaiming inanities like "Line TBC cleans the image, Frame TBC cleans the signal". In this video, the TBC can either work as "Frame TBC" only, that is, only V-sync alignment, so the image wiggles left to right, but does not roll. Or it can work as "Line TBC" + "Frame TBC", that is, both H-sync and V-sync.

In the end he mentions TBC vs time base corrector, clearly he misspoke. He meant TBC (with frame sync capability) vs dedicated frame synchronizer.