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-   -   AVT-8710 TBC specs? (http://www.digitalfaq.com/forum/video-restore/1496-avt-8710-tbc.html)

via Email or PM 07-23-2009 03:09 PM

I just called TVOne and talked to a salesman (bad idea). He tells me the 1T-TBC is overall better (proformance wise) than the AVT-8710.
It has continuously variable adjustments (eg.: a volumne control) vs 'stepped' adjustments (eg.: bass & treble controls for a car radio) with the 8710. He also says it has better freq. response than the 1T-TBC and can lock to lower quality signals. I asked him about the freq. response and S/N ratio of the 8710 and how many steps and db change each press of a button when using the Proc Amp controls. he had no idea (no surprise). he offered to pass me over to someone in technical.

I repeated the questions, but didn't really get any answers. There are published specs for the 1T-TBC, but none for the AVT-8710 other than size, weight and ins and outs. He then talked to someone else and admitted both have the same circuit board.

My questions are;
1. Can the plastic case of the 8710 be opened (screws), or is it glued?,
2. Has anyone opened it and took pictures?,
3. How many 'steps' plus and minus from center for each proc amp control? (that might need a scope to be sure unless you have a good eye).


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lordsmurf 07-24-2009 10:11 PM

AVT-8710 TBC specs?
 
4 Attachment(s)
I run into this problem more and more as time goes on. Companies swear their products are "better" than the competition, but the fact is that these these days many items are simply re-branded/re-badged items made by some no-name Asian supplier. And so are the competitor's products -- often from the EXACT SAME suppplier! In some cases, the salesmen aren't even aware of this fact -- it's not on their scripts.

The AVT-8710 is not glued, and it can be unscrewed. I've done this for you, and here are the images:

http://www.digitalfaq.com/forum/atta...7&d=1248490893

http://www.digitalfaq.com/forum/atta...9&d=1248490893

http://www.digitalfaq.com/forum/atta...9&d=1248490893

The last image, the one with the close-up of the board, is available in a higher resolution. Download the RAR file attached to this post, and the high res JPEG is inside. You can clearly read all of the numbers and parts on the board.

As far as the steps go, it's very minimal. I don't have the desire to test it with a scope, nor the available spare time -- it's honestly a really weak proc amp at best.

The adjustments step up, but it's very slight at each press of the button. I would imagine anything that is button-driven would have to step in a preset amount.

After several presses of the button, it stops responding, apparently having hit the maximum range of what it's allowed to adjust. I don't remember how many times it is, or if it's the same on all options (Tint, Sharpness, etc). If I recall correctly, it was about 10-15 button presses before it stopped responding.

A dedicated proc amp, even one of the older and less-expensive ($50-100 range) Vidicraft units, works far better. Processing in software would also yield a higher adjustment level.

B&H has the best price on buying new AVT-8710 units: http://www.bhphotovideo.com/c/produc...3167/KBID/4166

videobruce 07-25-2009 10:20 AM

I'm unable to view any of the pics. You say it's a "very weak proc amp at best". Are you referring to a small adjustment range as in not much latitude?

admin 07-25-2009 02:37 PM

Yes, the range is limited.

videobruce 08-06-2009 10:25 AM

Amazing what can be stuffed in a few chips. I bet that board costs $20 or $30 to manufacture in China. It wouldn't be much to get rid of that cheap plastic box,install that board it in a metal project enclosure along with the control board and 'brick' power supply with a power switch. ;)

For $200, one would think that would be the way it we be sold in the first place. :rolleyes:

I can see why it gets hot. No heat sinks on the regulator or any of the 'flat packs'.

lordsmurf 08-09-2009 02:01 PM

1 Attachment(s)
Hmmm.... I think (if nothing else!) that there is enough room inside this cheap plastic enclosure to add some RAM heatsinks. I did something similar to this on my LiteOn DVD recorder some many years ago, as it had no heatsink on the LSI Logic encoder chipset. I sawed a RMA heatsink in half, and then sanded and polished it smooth and clean. Using some heatsink tape, I affixed the customized/modded heatsink to the LSI, and it lowered the temp significantly. I did it on some other chips, too.

That alone may be helpful.

For an on/off switch, I've long resorted to unplugging the power cord from the unit itself (not the wall). I could use a surge/power strip, or make my own on/off toggle with a few cheap parts from Home Depot or Lowe's home improvement stores. It's never been a big an issue. Yes, for $200, I have to agree, it should have come with one!

I've also re-saved re-attached the last image, as requested. It is saved as a JPEG Medium in Photoshop CS3, it should not be an HTML image. I see those sometimes, too -- not sure what causes it.

http://www.digitalfaq.com/forum/atta...2&d=1249844384

videobruce 08-10-2009 08:08 AM

Thanks for correcting the larger photo.
Have you or anyone measured the frequency response? How transparent is this?
If you don't have a signal generator, you could use test patterns off of a DVD.

admin 08-10-2009 10:55 PM

I've not tested, but might try in the near future. Now you've got me curious as well.

dphirschler 08-20-2012 12:51 PM

Can somebody confirm that the 12vdc power supply is negative on the ring and positive on the pin? Also, if somebody can show a pic of the power transformer, that would be nice.

I've just blown mine up. Either I plugged the wrong transformer into it or it was just ready to go. There is a chance I can repair if I can get a soldering iron in there. The step-down converter has blown to bits.

Darryl

PS. I considered starting a new thread, but since this thread has pics of the unit, I thought that the pic of the power transformer would be helpful within the same thread.

kpmedia 09-14-2012 11:45 AM

2 Attachment(s)
Quote:

Originally Posted by dphirschler (Post 22553)
Can somebody confirm that the 12vdc power supply is negative on the ring and positive on the pin? Also, if somebody can show a pic of the power transformer, that would be nice. I've just blown mine up. Either I plugged the wrong transformer into it or it was just ready to go. There is a chance I can repair if I can get a soldering iron in there. The step-down converter has blown to bits.

Here you go...

This the main TBC on the second rack. It's an AVT-8710. I took a photo of the complete power supply, so you can see the mods. It uses a $4 switch from Walmart, along with a power extension that also comes from Walmart. (I think these are sold in 3-packs for like $6 or something.) Those switches and extensions can also be bought from Amazon.com. This gives the AVT-8710 a power switch, and it also plugs into a strip off the main UPS. Notice that the adapter itself is labeled with a Sharpie (black on black), to avoid adapter mix-ups.

Attachment 2902

Close-up of the AC adapter text:

Attachment 2901

More AVT-8710 / CTB-100 images can be found in this post: http://www.digitalfaq.com/forum/vide...html#post17020
That page is also the full FAQ on TBCs.

Quote:

PS. I considered starting a new thread, but since this thread has pics of the unit, I thought that the pic of the power transformer would be helpful within the same thread.
Good idea. :thumb:


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Nightshiver 09-28-2012 12:20 PM

Is there a way to make the AVT just a pass-through? Meaning, if all you want it to do is be a TBC and not have it do anything else?

meson1 10-10-2012 11:04 AM

These things really do get quite toasty. I'd be quite interested in modifying mine with a heatsink or two to improve it's power-on 'durability'. But I'm not an electronics expert. I'd need to be shown visually what it is in there that gets warm. Would anyone care to provide a pic annotated to indicate the thermally critical components?

admin 10-10-2012 11:14 AM

Hi meson. :)

It's the five large black chips that generate the heat. In the photos above, you seem all of them on the bottom-right triangular half of the board.

Small chipset heatsink kits are nothing more than a piece of thermal compound tape with a chunk of finned aluminum or copper. If you can operate a roll of tape, you can apply heatsinks. The ones made for computer graphics cards would be about the right size.

Newegg.com has the "Enzotech BCC9 VGA Cooler" kit for $17: http://www.newegg.com/Product/Produc...82E16835708009
Those are similar to the Zalmans suggested for ATI AIW PCI Express cards (ZALMAN VF900).

Drilling or Dremmeling some larger holes in the plastic (top and sides) may not be a bad idea, either. Those wussy little slits don't help very much for air flow.

It also helps to not overuse the unit (no more than 6 hours at a time), as well as avoid putting it inside of a cabinet or enclosed space where it cannot breathe. That's actually true of any video hardware. A lot of people fail to realize a hot VCR is a VCR that eats your tapes for dinner.

meson1 10-10-2012 11:21 AM

Great. Thanks. Yeah, I can do that job no problem. Also, it had already occurred to me that some extra airflow might be required, so some very careful drilling would be needed; in particular around the sides to let in cool air to replace the air convecting out of the top.

Some UK equivalents:
Overclock.co.uk - Koolance Video Ramsinks Aluminium 8PCS - HTS-GP001P
Overclock.co.uk - Zalman ZM-RHS1 GPU Memory Heatsink (8 PCs) - ZM-RHS1
Overclock.co.uk - Enzotech BMR-C1 High Profile Passive RAM Cooler - BMR-C1
scan.co.uk - Cooler Master Alloy Memory Heat Sink Tabs Cooler ARC-U01 - 8 Tabs

All usually come with thermal tape pre-applied. The main thing to be careful of with any such heatsink is to ensure they are not too tall. They mustn't come into contact with the pcb in the top of the case.

admin 10-10-2012 01:40 PM

Quote:

Originally Posted by Nightshiver (Post 23188)
Is there a way to make the AVT just a pass-through? Meaning, if all you want it to do is be a TBC and not have it do anything else?

Don't change the proc amp settings. That's it.

Quote:

Originally Posted by meson1 (Post 23369)
The main thing to be careful of with any such heatsink is to ensure they are not too tall. They mustn't come into contact with the pcb in the top of the case.

Good call. :thumb:

You may need to Dremel or saw off heatsinks that are too large. I've seen people simply use a chunk of copper from an old pipe, smooth and flatten it, and buy only thermal tape. There's a post on this site, where a forum mod (JMP) baked a laptop board to fix the solder, and then used this copper slab method to add a heatsink to a chip that previously had nothing.

Several ways to solve problems, if you're clever. :cool:

meson1 10-13-2012 07:32 AM

2 Attachment(s)
Okay. I've opened up my AVT-8710 and measured the size of the chips and the available headroom.

Referring to the image below:
http://www.digitalfaq.com/forum/atta...8710-openedjpg

The two small square chips at the bottom centre-ish are about 10mm x 10mm.
The two oblong chips in the bottom right are about 9mm x 18mm.
The large square chip on the right hand side is about 14mm x 14mm.
The available headroom from the top face of the chips to the secondary pcb in the top of the case I calculate to be 18mm.

To that end I have ordered some Enzotech MOS-C10 heatsinks. These wee babies below.

Attachment 3018

These measure 10x10x14mm. So they should fit one of each of the two small square chips and two jammed next to each other on each of the oblong chips.

I am also in the process of scrounging a spare one of these 14x14x14mm ones from a friend at work for putting on the large square chappie on the right:

Attachment 3019

These are Enzotech BMR-C1's.

When I get 'em, I'll fit 'em and maybe take a couple of pics for you.

jmac698 10-13-2012 10:18 AM

>The two oblong chips in the bottom right are about 9mm x 18mm.
18.10 x 7.60 maximum :) This is a standard SOIC-28 package. It's height is 2.65mm max.
The others are probably exactly what you measured.
Knowing this may help as heatsinks are made to fit the packages; so if you know the name of the package, you might find it in the description of the heatsink, so look for soic-28 heatsink.
If you use two for the soic-28 it should just exactly overhand the pins, and 1mm overhang the chip on the long side.

Here's one made to fit:
http://uk.farnell.com/fischer-elektr...-9b10-00001460

I see a Cypress CPLD, some ram, can't read one of them due to jpg compression artefacts.
It's nicely layed out for hand repair.

meson1 10-15-2012 04:17 AM

I was going to use a pair of MOS-C10's for those SOIC-28's. But I had a nosey round for the soic-28 heatsinks you mentioned and found a website selling them for pence with free delivery. So I put in an order for two.

I didn't fancy the idea of the MOS-C10's over hanging the pins by 1.2mm on each side. The SOIC-28's are surface mounted and there's not a lot of clearance, though they probably would have been fine.

Master Tape 07-28-2016 07:51 AM

Quote:

Originally Posted by Nightshiver (Post 23188)
Is there a way to make the AVT just a pass-through? Meaning, if all you want it to do is be a TBC and not have it do anything else?

Quote:

Originally Posted by admin (Post 23388)
Don't change the proc amp settings. That's it.

Doesn't the AVT make things a tad brighter, and you'd have to adjust the brightness by clicking it down twice on the proc-amp to correct things, or can this just be corrected in Avisynth each time after you capture?

sanlyn 07-28-2016 10:16 AM

Quote:

Originally Posted by Master Tape (Post 45097)
Doesn't the AVT make things a tad brighter, and you'd have to adjust the brightness by clicking it down twice on the proc-amp to correct things, or can this just be corrected in Avisynth each time after you capture?

Some models do, some don't. You have to adjust brightness and contrast to achieve safe yuv levels during capture anyway. Once you have a capture with valid levels, you can tweak further in post processing.

lordsmurf 08-23-2016 03:13 PM

Quote:

Originally Posted by sanlyn (Post 45100)
Some models do, some don't. You have to adjust brightness and contrast to achieve safe yuv levels during capture anyway. Once you have a capture with valid levels, you can tweak further in post processing.

^ Correct. :2cents:

The chipsets vary a lot, unit to unit, over the past 15 years.
It can also vary a lot base on on the source -- VHS, Hi8, digital cable, etc.

RS456 07-30-2020 05:35 PM

Can someone who owns the green AVT-8710 open it up and take the backside picture of both the boards? I think it is very possible to recreate this board and device. Who knows we can probably deal with the TBC shortage .

lordsmurf 07-30-2020 05:51 PM

Quote:

Originally Posted by RS456 (Post 70477)
I think it is very possible to recreate this board and device. Who knows we can probably deal with the TBC shortage .

Nope! Not even close. The good chips are 15-20 years old, and no longer made. It's also not solely about chips, but on-chip software. So you'd be reinventing the wheel with more modern hardware, newly written firmwares. I've worked with several people that tried to recreate TBCs. It's not easy. To date, all projects have failed. In fact, at this very moment, I'm working with a developer. It's probably the closest that things have gotten yet, but it's still in R&D/prototype stages, at least 6 months away, if it even happens.

BTW, most green AVT-8710s have sanded chips. So nothing can be read.

hodgey 07-30-2020 08:17 PM

From what we've documented in other threads, the AVT uses SAA7114 video decoder chips for decoding the analog video, the TBC-3000 (and possibly the TBC-1000 as well) use the older SAA7111. They're both off-the-shelf video decoders that were used in tons of stuff, but are now discontinued, though it seems they're still available second hand. It seems NXP, who last had the license for them stopped making video decoder chips in general.

The video chips output decoded video data in YUV 422 format with 720 pixels per line (or RGB but I don't think that's used here, and possibly also raw 8-bit CVBS, but that may or may not be only for VBI). They also have some additional outputs for sync signals (can also be embedded in the video output as described in ITU-R_BT.656). Most analog video decoder chips work in a similar manner.

In the TBCs this seems to be hooked up to some memory chips, which are then hooked up to a FGPA chip. This is where any custom processing would happen (if any). The AVTs also have a separate ROM chip hooked up to it, which presumably contain code to run on the FPGA. The FPGA presumably also translates key presses to commands to the video chips. The TBC-3000 seemed to have some FPGA chip or microcontroller with embedded ROM + some simple logic chips as well.

This is then hooked up on the other side to another memory buffer, and then to an off-the-shelf video encoder chip that converts digital component data to an analog signal. On a modern alternative one would probably want to output to HDMI, SDI or over USB as a capture device instead, no reason to turn it back to analog.

There isn't really so much magic going on here, if there are custom settings on the video decoder, it would be possible to read it off the serial connection pins of the chip. The FPGA may have some logic to decide on how to deal with data that comes in too fast or slow, but I don't see a whole lot that could be done with it. It's the video decoder chip that's doing the brunt of the work, and these chips originally made by philips are quite good at that. It's possible to dump ROM chips as well, but that gets into possible copyright infringement territory.

There are some other companies making analog video decoder chips still, Analog devices even has chips with built in line and frame TBC functions (provided it's hooked up to some memory.) Whether it's as robust as the Philips/NXP chips I don't know, it may be something that could work as a "modern" solution. I know some people on videohelp (not sure if they're here as well), have used their Eval boards as a TBC/Capture device of sorts.

Renesas and TI also still makes video decoder chips, but I don't know if they're as advanced.

lordsmurf 07-31-2020 06:31 AM

Quote:

Originally Posted by hodgey (Post 70480)
Analog devices even has chips with built in line and frame TBC functions (provided it's hooked up to some memory.) Whether it's as robust as the Philips/NXP chips I don't know

All information to date has shown that it's not. There are also multiple AD chips. The most damning instances are when HD cards have used the chips, yet completely falter on untimed SD input. This has been tried multiple times in the past decade, and each project is eventually abandoned. Note that the AD chips pre-date EOL'ing by Cypress and DataVideo, who exited the TBC market due to chips needed no longer be fabbed, supplies ran dry. I would think either, or both, would have jumped on AD had it been a solution.

Remember: TBC is a wide term, and marketing often rapes it.

The AD chips have contained various weasel terms like "ADLLT" and "mini TBC" to describe what actually happens in-chip. That doesn't inspire much confidence. And again, indy projects have all failed to date, and the TBC makers apparently didn't see those as viable alternatives before EOL'ing all TBCs.

I recently postulated something else sinister, when it comes to HD cards. You know how Blackmagic and Magewell cards can drop/repeat frames, even with frame TBC (ie, DataVideo TBC-1000) in the workflow? Odds are good that it's TBCs clashing. The AD-chip TBC is so weak on-card that the SD input fails. But the external frame TBC conflicts with the on-board wimpy TBC, to create the drop/repeat effects. I don't know why I had never thought of this scenario, but it's one I've run into with VCR TBCs, DVD recorder TBCs, and external TBCs.


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