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-   -   Datavideo TBC repair experience? (https://www.digitalfaq.com/forum/vcr-repair/12274-datavideo-tbc-repair.html)

latreche34 01-14-2022 12:07 PM

Quote:

Originally Posted by RobustReviews (Post 81864)
It's a bit curious why Y/C is omitted though, if anything it's easier to deal with than a composite signal <- I'm only just learning about this though, so there's a good chance I've massively overlooked something.

Because it was initially designed as a processing device for laserdisc and CCTV camera's that use composite, It was never intended for a VCR, I kept trying to convince him about making a box for VCR first then a whole VCR machine, From the PDF attached it looks like they do have a prototype with Y/C input, will they make a final product for sale? that remains to be seen. If they do make one for less than $1000 it is great deal, USB 3.0 port is not that important as you can get digital SDI AVI into computer in a bit perfect manner with many different ways. The current SM03 composite version is selling for £595.

RobustReviews 01-14-2022 12:20 PM

Quote:

Originally Posted by hodgey (Post 81874)
The only "critical" component of the Datavideo and AVT TBCs that is no longer produced is the SAA7111 and SAA7114 video decoder chips.

These are interesting, I have a couple of these I need to have a play with.

Sync' detection varies quite a bit from what I've researched so far, it's unclear in the Philips datasheet as to how it's determined, but (going back a few posts) some of the cheap 'n' cheerful sync' separators I purchased earlier are quite crude, theoretically, they can sync' between 11% and 50% of the falling edge of the sync pulse... Good enough for fiddling with for experimentation, but probably not especially accurate compared to some methods.

RobustReviews 01-14-2022 12:28 PM

Quote:

Originally Posted by latreche34 (Post 81875)
Because it was initially designed as a processing device for laserdisc and CCTV camera's that use composite, It was never intended for a VCR, I kept trying to convince him about making a box for VCR first then a whole VCR machine, From the PDF attached it looks like they do have a prototype with Y/C input, will they make a final product for sale? that remains to be seen. If they do make one for less than $1000 it is great deal, USB 3.0 port is not that important as you can get digital SDI AVI into computer in a bit perfect manner with many different ways. The current SM03 composite version is selling for £595.

Ah, mea cupla, I didn't realise it was designed with LD in mind. I might order one of these over the weekend and have a look.

It's FPGA based, which is interesting. :congrats:

lordsmurf 01-14-2022 12:32 PM

Quote:

Originally Posted by hodgey (Post 81874)
I know LS is not a fan of the ADV chips

I do like ADI's chips, but the "line TBC" is nonsense/BS, especially with defaults. It's weak, fails easy, even on common sources. At times, even makes it worse. Most devices using this chip don't have this function enabled, likely for these very reasons.

TBCs are more than single chips, or even the default chipset instructions.

You must be careful with RAM. There are side effects that result in things like the black AVT-8710. So you can't just grab any random RAM, and call it good. Nope.

mbassiouny 01-14-2022 05:11 PM

Quote:

Originally Posted by nicholasserra (Post 81849)
Currently have 3 tbc1000s that I'd love to send to someone to recap and do the distribution plate bypass. Messaged the dude who is selling the crazy modded ones on ebay with no response. Messaged a dude on youtube who said he did these mods and never heard back.

the "crazy mods" guy is ccbradley https://forum.videohelp.com/members/299781-ccbradley
I have dealt with him few months ago, He is a nice guy. sadly He seems to be AFK since about 2 months at least (also his last seen on video help is august)... Not so reassuring I hope he is ok and just taking break from the Web or sth.

Quote:

Odds are, if it ever sold, it'd never be shipped. I'm quite glad I didn't send him a TBC-1000 to be modded, which he wanted me to do. But I don't trust nobodies with TBCs.
I don't think he is doing it out of bad intentions. He actually still has a bit more TBC units than the ones on eBay. To be honest, I think sth happened...

Quote:

Originally Posted by nicholasserra (Post 81849)
Need to go hit up my electrical engineering friends and figure out a long term solution here. Some kind of new hardware or something.

Yeah, a new solution may be needed, but don't forget that green avt's are dead. Black do not count. CTB/Globalmedia/ambery/hall and other rebranded clones were rare to begin with and people sitting on these won't sell them (they don't know their value, for them these are 20$ cheap crap). Tapes are starting to die. In ~10-15 years the entire VHS digitization thing will be almost fully dead anyway, which will reduce demand on TBCs by like 90%. So We just need the few alive TBCs to keep circulating properly.

R&D costs money, There is theory behind, you don't need EEs only. Community projects will not yield a cheap product, it won't be there to lower cost, but at least will solve the shortage issue. To lower costs you need proper manufacturing procedure, with quantity which is costly overall, but reduces the cost per unit. I am willing to "invest" some money in such a project, but I don't think anyone is close enough to achieving something viable. Maybe it will be easier if some "experts" with some petitions and some crowdfunding manage to convince datavideo (or even cypress!) to produce like an extra batch of 3000-4000 units, this will relax things a lot! And since they were profitable enough for Datavideo when they retailed for 400$ it means the cost is less then 400, if they sell them brand new for 600$ we, consumers will be happy and they will make a lot of profit compared to old batches sold in 2000-2010.

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"Normal people" were never the targeted demographics. Normal people need to take their videos to a competent service, and done
Trust me, you are overestimating commercial services. Most of them look pro for the average person but they give trash quality, only people who know how to capture can see the flaws. Flawed or rack mount/mixers TBCs, flawed capture cards, or high end VCRs that are not in a good shape. (I am talking about local services in the country where I live at, at least).

lordsmurf 01-14-2022 05:55 PM

Quote:

Originally Posted by mbassiouny (Post 81887)
In ~10-15 years the entire VHS digitization thing will be almost fully dead anyway,

I thought that 10 years ago. And yet, here we are. :unsure:

Quote:

which will reduce demand on TBCs by like 90%. So We just need the few alive TBCs to keep circulating properly.
And that's the issue. The AVT-8710 burn themselves out, especially (sadly, commonly) overused. We now see a mere handful of these per year. The TBC-1000 began to fail in 2019, both caps and chips. So that once-reliable unit can be a dud, especially units from eBay (as the recycler sellers don't know TBCs from toasters). That leaves some other units, but not without their own issues. It often takes somebody to refurb the unit, in order to put it back into good condition. I've been doing this for 7 years now ... 7 years, wow. I've had some folks ask "tell me how you did it", but it's a unit-by-unit approach. I still see errors for the first time, sometimes. I've taught a few things to a few folks, but it's for their specific unit. Not even the model, their unit.

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R&D costs money,
Thousands, easily. Everybody thinks R&D is a single step, then done. No. They overlook all the failures, and those cost money too.

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convince datavideo (or even cypress!)
No. They've moved on.
See also above. R&D needed again, not enough reward for the risk.

Quote:

to produce like an extra batch of 3000-4000 units, this will relax things a lot! And since they were profitable enough for Datavideo when they retailed for 400$ if means the cost is less then 400, if they sell them brand new for 600$ we, consumers will be happy and they will make a lot of profit compared to old batches sold in 2000-2010.
I can appreciate the random math, the "hey guys, we can do it!" type energy, but no. Those numbers are way off base.

And I'm pretty sure that DataVideo never retailed for $400, more like $500 + shipping. The MSRP was much higher, and there were lowball "street prices" at shady NYC camera/video shops in the 90s. And none were in stock, or wink-wink it actually costs more. I have old magazines from the 90s, that shows gear and prices from places like B&H, or the scummy NYC fake prices.

Quote:

Originally Posted by mbassiouny (Post 81887)
Trust me, you are overestimating commercial services. Most of them look pro for the average person but they give trash quality, only people who know how to capture can see the flaws. (I am talking about local services in the country where I live.)

Not at all. "Competent" is the real problem. But there are some out there, including members (and lurkers, I see you! :P) on this forum.

The main issue is this was a business model of the 2000s. It's now a legacy task, and sometimes DIY is the only sensible option (vs. service). So congrats, Mr. Normal. You have a new hobby! (Or put the tapes back in the closet. If you never want to see video of your grandma again, it probably won't affect me. That's sad, but some folks just don't care.)

People procrastinated for decades. Wait a few more decades, and your tapes will be ruined. So if you decide that DIY is best, suck it up, accept the costs of the tools. It's just a project. Buy it, use it, then resell it. Done. The conversion service wasn't going to be cheap or free anyway. It would cost money either way. At least the hardware costs can be recouped, sometimes even profited from. The tradeoff of DIY is time and learning curve.

Lots of quality places (and crap shops) long ago closed up, moved on, retired even. Many also assumed VHS conversion was temporary, over by the 2010s. The 08-09 recession wiped out quite a few businesses as well. Most were VHS-to-DVD in those days, not other formats, so waiting was actually a good thing for many, in terms of quality. Lots of folks are redoing shoddy 2000s (and even 2010s) work these days..

mbassiouny 01-14-2022 06:47 PM

Quote:

I thought that 10 years ago. And yet, here we are.
Umm, I believe at least early tapes are dead, right? maybe good tapes and "end of vhs era" tapes are still alive. But event these will eventually die even if not in 15 years, they surely will.

Quote:

> The AVT-8710 burn themselves out
Too bad the variant in metal chassis was not so popular (because directly sold by cypress themselves) except for the tV one, which is mostly defective, I believe (but feel free to correct me if I am wrong), that these may be as "reliable" and well built as datavideo-1000...

And yeah, it's some random math haha, but I still feel like even with proper math, it might work now.... maybe the numbers did not work when they decided to retire (saturation of market), but now that 2nd hand gear is dying, there might be a place for new units again, specially from companies who already have the know-how...

Quote:

People procrastinated for decades.
Some of US were just no born hahah.(or were at least too young to know any thing about VHS ) We don't all digitize family tapes, some of us digitize old movies and shows that never got a proper bd/dvd release

Quote:

Many also assumed VHS conversion was temporary, over by the 2010s
This was around the same time Datavideo stopped making new TBCs right? if so, it makes sense. Everyone thought the market was dying for this, but it turned out to be temporary.

lordsmurf 01-15-2022 10:34 AM

Quote:

Originally Posted by mbassiouny (Post 81889)
Umm, I believe at least early tapes are dead, right?

Dead, no. Problems, yes. 1970s and early 80s especially, such as BASF. Time to migrate those was yesterday (yesterdecade!). Do not wait.

Quote:

maybe good tapes and "end of vhs era" tapes are still alive. But event these will eventually die even if not in 15 years, they surely will.
Nah, just more problems. And it will have to get more expensive to transfer, due to gear maintenance costs from tapes. And/or lowering transfer quality, unwilling to put problem tapes in best gear. Gear meant for problem tapes, that is -- NOT your daily gear!

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Too bad the variant in metal chassis ... I believe (but feel free to correct me if I am wrong), that these may be as "reliable" and well built as datavideo-1000...
The plastic case didn't help the AVT-8710, but other Cypress were not immune. The small form factor doesn't help, the boards had everything too close together. It was far more robust, could be used longer, will last longer. But still cannot be abused -- overworked, left on too long. There were a few early 2000s European PAL-CDM models that were built more like TBC-1000, and had room inside for added heat sinks. But those were mostly sold to studios, for demi-racks, and thus abused (overworked). So we arrive back at the same problem, few left now.

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Some of US were just no born hahah.(or were at least too young to know any thing about VHS ) We don't all digitize family tapes, some of us digitize old movies and shows that never got a proper bd/dvd release
Remember, I started as a cartoon collector. I'd much rather watch Bugs Bunny than somebody else's camcorder tapes.

Quote:

This was around the same time Datavideo stopped making new TBCs right? if so, it makes sense. Everyone thought the market was dying for this, but it turned out to be temporary.
With a lot of companies, in the post-08/09 recession (which arguably lasted well into 2012 or longer, for some/many), it was about cutting and surviving. Refocus on most profitable products/services, cut the rest. That normally happens, but was far more draconian post-recession. Analog was over, consumer analog was over, VHS was over. So it essentially mass ended. Self fulfilling prophecy, somewhat. They thought it was over, so it was over. But then it reversed for the consumer, not that it really ever quit, especially during the pandemic. (The FY20-1H21 part of the pandemic actually used up all of the oxygen for the 2H21-1H22, so we'll need to see how 2H22 looks, but won't really know until well in Q4. What's left, who's left? Was more oxygen actually used up than we know, and wipes out FY22 into 23 or longer?)

nicholasserra 01-15-2022 05:39 PM

Quote:

Originally Posted by Diopter_Doctor (Post 81857)
If you're interested in having it recapped and/or having a cable made, just PM me and we talk about price. What's your use case for these TBCs?

Definitely interested in the cable. I had the same thought, but realized they didn't have the svideo connector on the tbc100 boards inside the units :( But a cable that connects from the tbc100 board and converts to svideo would be amazing. I'll PM you.

Use case is that I do archival of concert footage for several fan organizations. A few hundred master tapes a year at this point. Here's the current state of things: https://twitter.com/nicholasserra/st...62398143111174

But i'm at the point where I'm buying duplicates of gear and needing refurb on stuff just for piece of mind.

Quote:

Originally Posted by lordsmurf (Post 81865)
Wait until March. Then PM me. ;)

Will do, thanks!

The other main frustration I have is lack of repair documentation. Even from enthusiasts. I know some folks consider that trade secrets. But right now NOBODY seems to be advertising repairs on these, so I wish people would just let this information free. Share the knowledge.

Smurf I know you were working on some kind of tbc1000 guide. Hope that's still in the works.

Quote:

Originally Posted by lordsmurf (Post 81865)
"Normal people" were never the targeted demographics. Normal people need to take their videos to a competent service, and done. Video gear is for the DIY'ers, the hobbyist, the semi-pro, and the pro.

My observation was more from the perspective of seeing people hop on here or videohelp asking for advice on digitizing their tapes, and getting responses like "You have to have a TBC". That recommendation clashes directly with the current state of things. So I read a response like that and think ... "They literally can't get one".

So is it helping them, or just adding confusion? Or should the response always be "If you're not ready to drop 3k on gear you need to call a professional." Maybe. But then again, who's even offering these services?

Seems like a no-win for the average person who wants to figure out how to do this but doesn't have deep pockets.

Maybe that's just where we are now. Tape digitization is now a game where, unless you're building out a serious rig, it's not worth even looking into.

mbassiouny 01-15-2022 05:58 PM

Quote:

Originally Posted by nicholasserra (Post 81912)
My observation was more from the perspective of seeing people hop on here or videohelp asking for advice on digitizing their tapes, and getting responses like "You have to have a TBC". That recommendation clashes directly with the current state of things. So I read a response like that and think ... "They literally can't get one".

So is it helping them, or just adding confusion? Or should the response always be "If you're not ready to drop 3k on gear you need to call a professional." Maybe. But then again, who's even offering these services?

3k? Last person that ask me for recommendation and wanted to buy an advc-55 from me, I told them one to read more on digitalfaq (but some people just can't read much here, language barrier). I told them their Kitchen VCR won't do. They got all angry and started to rethinking about the entire thing and consider asking "profesionals". Pros... euh, no minimal restoration, most I have seen would pair good JVC with an advc, without frame TBC, or would use a lousy HD capture card, or even worse, I have seen many who camcorders as passthrough to output DV.

IMHO, It does not really take deep pockets, if your tapes are acceptable and you want "something" to watch for nostalgia and memories, not doing some archival (i.e not your case with concert archival) then do it without a TBC.

You won't digitize a tape for less than 10€ here. if you have 30+, 300€, so just buy good VCR and capture card (+ maybe TBCish dvd recorder), use it, sell. When you sell, if you are unlucky and don't sell for what you bought for, you will still lose less than those 300€! If you are lucky you might even sell for more than what you paid!

Honestly, "buy it, use it, sell it" (quoted from LS) is like digitizing your tapes for free (or for a very cheap price, if you sell a bit cheaper than what you paid). If you have less than 20 tapes, and 0 knowledge, and don't care about learning for the fun of it, then don't even bother (imho).

Quote:

Originally Posted by nicholasserra (Post 81912)
Seems like a no-win for the average person who wants to figure out how to do this but doesn't have deep pockets.

Maybe that's just where we are now. Tape digitization is now a game where, unless you're building out a serious rig, it's not worth even looking into.

Yes, that's just where we are now. Some rare shows, sell for 300$ (sometimes more), but 10-15 years ago, you would buy it for 30-50$.

lordsmurf 01-15-2022 06:43 PM

Quote:

Originally Posted by nicholasserra (Post 81912)
But i'm at the point where I'm buying duplicates of gear and needing refurb on stuff just for piece of mind.

Smart. I have extra VCRs, TBCs, and capture cards that I may never need or use. But I'd rather have it, and not need it, than need it, and not have it. Scout motto: Be prepared!

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Smurf I know you were working on some kind of tbc1000 guide. Hope that's still in the works.
Yes, but it needs to follow a certain timeline. We're not there yet.

Quote:

So I read a response like that and think ... "They literally can't get one".
I have 6 available right now in the marketplace. :hmm:

Quote:

Or should the response always be "If you're not ready to drop 3k on gear you need to call a professional." Maybe. But then again, who's even offering these services?
They're out there. Research. For example, I take in projects (but due to health I have to be selective with what projects I can accept).

Quote:

Seems like a no-win for the average person who wants to figure out how to do this but doesn't have deep pockets.
That's revisionist.

It never was. The "average person" was too lazy to read, too cheap.

Remember, I've been around since before we had viable digital transfer methods.

Years ago, capture cards were just as expensive as TBCs (which cost less then than now), VCRs have never really changed price ranges (then new, now non-refurb'd used, though somtimes gambles). Back then, you had to have a powerful computer, not some cheap POS Celeron.

So ... no. The status quo is unchanged. DIYers, hobbyists, semi-pro, pro. Not John Q. Dumfuk. But also realize to even have the notion to post on VH/here/wherever, puts you in the non-"normal" category. The demographic of these sites isn't Jane Bucktooth, it's Jane Serious, who wants to do video. Youtube is where you find Donald Duh and Barbie Braindead, spending $2 on Wish because some "little weird" doofus told them gullible BS. The problem with John Q's site (Youtube, Twitter) has always been when smart people start to get stupid advice.

Quote:

Originally Posted by mbassiouny (Post 81914)
. I told them their Kitchen VCR won't do. They got all angry

Some folks just hate truth, facts, science. If this was easy, everybody could do it blindly with anything. And we'd not have decades worth of online Q&A due to the complex problems from video conversion.

Quote:

IMHO, It does not really take deep pockets, if your tapes are acceptable and you want "something" to watch for nostalgia and memories
Some form of TBC is required, period. The worse and more pathetic that is, the more issues you'll face. The better it is, the less issues. So money = time, stress, difficulty. More money means less, less money means more. Simple equation. The ideal no-problem workflow is true line+frame TBC. There's nothing "professional" about that, but most pros do choose that path of least resistance. That's what those tools exist, after all. To make video life easier.

Diopter_Doctor 02-05-2022 02:23 PM

1 Attachment(s)
Just a follow-up post for the custom cable for the TBC-1000 bypass I mentioned earlier. I recently made more for a member on here and just wanted to add a picture.

One cable is coming from the S-VHS player and the other is going straight to my capture card. This lets you bypass the distribution amp for those concerned about noise or that don't want to replace all of those capacitors on the amp board.

P.S. this is before I tightened down the heat shrink, so forgive the aesthetics. :cool:

mrmuy97 03-20-2022 02:08 PM

Quote:

Originally Posted by Diopter_Doctor (Post 82598)
Just a follow-up post for the custom cable for the TBC-1000 bypass I mentioned earlier. I recently made more for a member on here and just wanted to add a picture.

One cable is coming from the S-VHS player and the other is going straight to my capture card. This lets you bypass the distribution amp for those concerned about noise or that don't want to replace all of those capacitors on the amp board.

I know nothing about this unit but wanted to say nice DIY work on that. Does bypassing the dist amp yield superior quality (never/rarely/sometimes/etc)? Or is it exclusively a trade-off for, as you mentioned, those who don't wish to have new caps on the amp board but still want to be able to use the unit overall?

Diopter_Doctor 03-20-2022 03:26 PM

Quote:

Originally Posted by mrmuy97 (Post 83559)
I know nothing about this unit but wanted to say nice DIY work on that. Does bypassing the dist amp yield superior quality (never/rarely/sometimes/etc)? Or is it exclusively a trade-off for, as you mentioned, those who don't wish to have new caps on the amp board but still want to be able to use the unit overall?

Better visual quality always, if your amp board has bad capacitors. But remember, the point of a full frame TBC is not to clear the picture, but to stabilize/ clean up the analog signal itself ( on an o.scope). You just don't want it to add visual noise while stabilizing the signal. When you reduce the amount of pieces in the video chain, the signal will have less noise... this is true for any analog signal. The question is, by how much? Since 480i analog home video is such low quality to begin with, giving it the best chance is what I'm aiming for. That's why I bought an SVHS player, recapped the TBC video processor board, and shield my cables.... and bypassed an unnecessary amp board.

To go a step further, you could exchange the switch mode regulator with a linear one. Again, less noise.

If you are a nerd like me and just want to see how good you can get your recordings, the cables are high quality for that reason. And if you spent enough money to have a FFTBC, you obviously care enough about the final product more than a standard user.

latreche34 03-20-2022 03:36 PM

The distribution amp was design for multiple VCR recording from a single source back in the day, It doesn't have any purpose for capturing and should be removed.

There is a guy by the name of ccbradley over at vhelp who did a nice restoration and modification of the device:
https://forum.videohelp.com/threads/...light=tbc-1000

Diopter_Doctor 03-21-2022 03:56 PM

Quote:

Originally Posted by latreche34 (Post 83562)
The distribution amp was design for multiple VCR recording from a single source back in the day, It doesn't have any purpose for capturing and should be removed.

I wouldn't go so far to say you should remove it from the unit.

You could take it out IF you
a.) know how to design a new small PCB to receive the incoming 12V ( I would add a fuse while you're at it) to replace it with.

or

b.) are using a broken unit for parts-only and need it to Frankenstein a fully working one.

I chose to keep mine fully stock but bypass the board with a custom cable.

mrmuy97 03-22-2022 04:05 PM

Quote:

Originally Posted by Diopter_Doctor (Post 83560)
When you reduce the amount of pieces in the video chain, the signal will have less noise... this is true for any analog signal. The question is, by how much? Since 480i analog home video is such low quality to begin with, giving it the best chance is what I'm aiming for.

Same.

Quote:

Originally Posted by Diopter_Doctor (Post 83560)
If you are a nerd like me and just want to see how good you can get your recordings, the cables are high quality for that reason. And if you spent enough money to have a FFTBC, you obviously care enough about the final product more than a standard user.

Yes we are on the same page there. I've done pretty extensive (de)soldering with components, although only down to the SMD resistor scale, on other electronic projects, so I may look into doing direct Y/C BNC connections to replace the mini-DIN s-video plug at some point. I have an assortment of cables with Neutrik BNC connectors on Belden 4855R cable (of course that's way overkill for this signal). But for now I have 8" Extron s-video to Y/C BNC split cables. I noted that inside an AJA Kona breakout box, the SDI-in to SDI-out internal passthrough connection is a pretty thin wire. I'd hope it's engineered to be more than enough and to have no interference/loss/etc, but you never know.

Quote:

Originally Posted by Diopter_Doctor (Post 83584)
I chose to keep mine fully stock but bypass the board with a custom cable.

Any chance you have more pics or description of the process? I have seen the ccbradley thread talking about how he mods the 1000s, but don't recall seeing specific info on the soldering of new s-video connections to the boards. If I looked into that, it'd be for adding Y/C BNC connections at the back of a unit to bypass the s-video mini-DIN.

Diopter_Doctor 03-24-2022 09:51 AM

Quote:

Originally Posted by mrmuy97 (Post 83629)
...so I may look into doing direct Y/C BNC connections to replace the mini-DIN s-video plug at some point.

I see the aesthetic benefit of doing that (especially since you already have coax cables) but there is no advantage of BNC over 4-pin MiniDIN. In fact, it's easier to find shielded (at least of some flavor) s-video cables for much less than some of these other cables.


Quote:

Originally Posted by mrmuy97 (Post 83629)
Any chance you have more pics or description of the process? I have seen the ccbradley thread talking about how he mods the 1000s, but don't recall seeing specific info on the soldering of new s-video connections to the boards.

I don't hardwire anything permanent on my unit, I simply intersect the video board's outgoing signal before it goes to the amp board with a custom made s-video cable. (I do sell them if anyone needs one, just PM me)
(I also recapp/refurbish TBCs if anyone needs that either).

But there are countless ways you can reconfigure your output permanently. Another member on here is simply adding new holes in his case for direct output. I'm not a fan of that kind of modification unless it is the only option to truly enhance the performance beyond the way it was originally made, but to each his own, I guess.

RobustReviews 03-30-2022 08:52 AM

Just an aside, and maybe it's been tried, but it has been tested to just terminate off the unused outputs on this distribution amp hasn't it?

For the $2 it costs for a bag of 75Ω terminators, it might prevent these issues that are being encountered?

With BNC/Coax, it's a deep topic. BNC with properly specified coaxial cable will yield better results, coaxial cable is a whole topic in itself, your transmission loss and reflection are far more neatly controlled with properly specified coaxial connections. Professional gear will generally use coax unless it's for interfacing with a specific signal type or domestic equipment.

However, at VHS quality, shortish cable runs and there's nothing inherently wrong with using S-Video, it won't be a startling difference.

If you really do want to push for ultimate quality, there is a small argument that coaxial may be better in this application, but you'll need to squint to see it.

Low-quality S-Video cables are annoying, poor quality coaxial connections will send you round the twist trying to work out where the problem is. Coaxial cable is complicated, and there's plenty of low-quality junk out there, it 'should' be the preferred interconnect but it's not feasible with a lot of equipment, and in reality, it makes little to no difference for DIY efforts from VHS sources. If long cable runs are your thing, then naturally coaxial is the way to go.

Then once you've done that, you can get into matching stages, we have some equipment that's matched, but that's total overkill here, and I'm not convinced it makes a difference, but if you want to squeeze out the nth degree of quality it's something that you could (theoritcally) consider... If you've got time on your hands, and literally nothing better to do with your time :P

Diopter_Doctor 03-30-2022 09:15 AM

Quote:

Originally Posted by RobustReviews (Post 83833)
Just an aside, and maybe it's been tried, but it has been tested to just terminate off the unused outputs on this distribution amp hasn't it?

It's more so about reducing the amount of parts in the video chain as well as avoiding the aging components. But it's worth a shot if someone has those laying around.

From my testing, the output brightness is no different using vs bypassing the amp board, so I don't think it's a termination issue. I would imagine it is terminated 75ohm to ground on the processing board before being amplified. I'm not an electronics engineer, and I don't have the service manual schematic but that would make the most sense to me.


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