TBC on Yamaha receivers

[ofesad]

Couple of years ago I was researching some alternatives to TBC's and Frame Sync's, looking for IC's, wich ones are usually found and worth investigating and so on.

I develop'd a list of Yamaha AV Receivers, wich among them there are several IC's with TBC-like functionality:
ADV7181, ADV7401A + IP00C772, ADV7401 + M2A-N, ADV7401A + MATISSE 1A G,ADV7800, ADV7180, ADV7441A, etc.
Most have a Mini-TBC functionality provided by adaptive digital line length tracking (ADLLT), signal processing, and enhanced FIFO management.

But I found that the ADV7800/7802 has built-in TBC and Frame Sync functionality, at least that's what the spec sheet says:
"Advanced TBC with frame synchronization, which ensures nominal clock and data for nonstandard input".

Then, researching several Yamaha's service manuals I found that IC is found on:
YAMAHA RXV663
YAMAHA RXV665 (No S-Video. Composite only. HDMI Output)
YAMAHA RXV1065
YAMAHA RXV1067/RXA1000
YAMAHA RXV2067/RXA2000
YAMAHA RXV3067/RXA3000
(probably others too)

Most of these have Composite + S-Video input and Output. Plus the HDMI output, of course.

In the past years I have been looking to get one for testing, but I haven't found one or the price was way out of my budget (is hard to live in Argentina).

So, it's worth testing just to check how good or bad the IC behaves for analog video capture (also worth if you capture thru HDMI).

Probably it won't be as good as a full frame TBC or a Datavideo, but if you have one or you can get one for cheap (wich, you shoulnd't worry about the speaker outputs, only AV and HDMI) or ask a friend for one that probably they have laying around or a visit to Goodwill!.


Note: You can access the Yamaha service mode to enable/disable the TBC functionality for testing purposes.


If anyone has already try'd one, I would like to read the comments and experiences, good or bad.

Ofesad

[dellsam34]

Interesting discovery, Ensemble Designs used it in the BE series, Grass Valley formerly known as Snell & Wilcox also used the ADLLT technology in a wide variety of analog to digital converters in the 1/2 and full rack sizes, They both used some of those chips you mentioned.

If I come across one in the thrift store I will give it a try, I won't go to the length of buying one online though since I don't need one.

[ofesad]

Interesting discovery, Ensemble Designs used it in the BE series, Grass Valley formerly known as Snell & Wilcox also used the ADLLT technology in a wide variety of analog to digital converters in the 1/2 and full rack sizes, They both used some of those chips you mentioned.

If I come across one in the thrift store I will give it a try, I won't go to the length of buying one online though since I don't need one.

Thank you for your comment, dellsam34!! I remember watching your post(s) regarding the BE and the GV components and ICs!
(Just the other day I got an ADVC G1 mint, complete in box, never used)
When I started researching this I took note of them to compare'em to the Yamaha's.

Also I contacted to the Japanese IC factory that made the custom ics for Yamaha, but they didn't want to give me any specs.

At the end it's all pretty much ADV-7XXX ic, but I haven't found devices using the 7800s except for these.

Ofesad

[dellsam34]

Makes me wonder if all Yamaha's receiver features the DSP Cinema logo on the front would have such chips, makes sense to have ADC chips to do such digital signal processing wouldn't it?

[ofesad]

Makes me wonder if all Yamaha's receiver features the DSP Cinema logo on the front would have such chips, makes sense to have ADC chips to do such digital signal processing wouldn't it?

The DSP shouldn't matter (even tho all have it). Basically, the rule of thumb is: if it has analog input (svideo/composite) and HDMI output, it would have an ADV-7XXX ic.

I have an Google Sheet with all the models I had been documenting (over 30) and wich IC has, if it has HDMI output, Svideo in, Svideo out, TBC, so on.
I just posted the ones that have the ADV-7800/7802.


So far, the only ones that don't have ADV-7XXX are the ones without HDMI output.


Another example: The Blackmagic MINI ANALOG TO SDI has the ADV7842, but they didn't enable the TBC/FS function. In theory it would be as simple as on/off.


Ofesad

[ofesad]

Found this online time ago.
A comparision between a capture using vhs-decode vs AD7842 (Evaluation board + HDMI capture)
https://www.youtube.com/watch?v=05MZeUf-Lkk

[dellsam34]

That content does not qualify for comparison, too flickery, edges are not defined, moving blotches of colors ..etc.

[Gary34]

The Pinnacle movie boxes have an ADV 7180. https://forum.videohelp.com/threads/401570-Hauppauge-USB-Live2-vs-IO-Data-GV-USB2

[lordsmurf]

- Single chips are not TBCs.
- The Analog Devices chipsets have serious problems, which is is why the psuedo-TBC(ish) PLL is almost always disabled.

People have been looking at the chips for over a decade now. It's nothing special.

[aramkolt]

Found this online time ago.
A comparision between a capture using vhs-decode vs AD7842 (Evaluation board + HDMI capture)
https://www.youtube.com/watch?v=05MZeUf-Lkk

That's a pretty interesting comparison - unfortunate that they used composite going into the AD7842, S-Video input would have been a fairer comparison. Of note, there are still visible line dropouts on the Decode capture which never made sense to me since it should be able to mask those really well, unless it was a second generation or more tape.

[Gary34]

Single chips are not TBCs.
- The Analog Devices chipsets have serious problems, which is is why the psuedo-TBC(ish) PLL is almost always disabled.

I realize it doesn’t have a TBCish effect. I’ve connected it to a regular VCR with my frame sync TBC or my Panasonic 1980 with no frame sync TBC. I can tell it needs both. How is it disabled? Is it the VCR input button in crossbar?

[aramkolt]

I went down the "receiver" rabbit hole a bit when I'd read that some laserdisc enthusiasts preferred using their audio receivers for deinterlacing/comb filters instead of DVD recorders.

Another mentioned specifically for the Analog devices chips were the Marantz NR series of which there are many models and I'd imagine if you live in a larger city, you can probably even find those locally on Facebook marketplace or similar.

The trick with the stated Analog Devices chip features is that some of them require external SDRAM to work. ADLLT is handled in the "SDP" area of the chip, see this snippet from the 7842 EVAL board manual:




Above, the manual describes that the RAM is needed for 3D comb filtering (which doesn't matter for S-Video sources) AND for frame sync features. Frame sync here probably being some of the frame TBC functionality described elsewhere in some features lists and likely why some devices with AD chips can accept unstabilized signals and others can't (like the ubiquitous Blackmagic Analog to SDI Mini Converter). It could be that later AD chips had built-in RAM, this was just grabbed from the 7842 dev board since we know it stabilizes laserdisc quite well.

I think the one device that we might collectively agree "acts" like how ADLLT is described to work is the TBS800 based on Dellsam34's observations here:

https://forum.videohelp.com/threads/402431-New-Device-Tested-for-TBC-Functionality

Compare the BE75 capture to the TBS800 capture and you can tell the TBS800 is doing something that the BE75 is not. Could be that it has the SDRAM available for the frame sync or that other features are enhanced when RAM is present. A picture wasn't shown of the underside of the TBC800, so I don't know for sure that there's ram present for the AD chip, or it could be some extra magic is being worked by the FPGA that is under the large heatsink maybe.

Brighteye and Snell and Wilcox professional units work well for frame TBC's in my experience, but I usually am feeding them pre-line corrected sources, so I don't know how well they actually work as line TBCs on difficult tapes, outside of the TBS800 example given above of course.

Not claiming to be an expert, so this can all be wrong, just some observations and thought chains I've had over the years. What I really need to do is do more head to head testing once I determine the best repeatable test that doesn't rely specific bad tapes.

[dellsam34]

RAM is required for any DSP operation, Line/field TBC, frame sync, DNR ... etc.

You can see clearly the 4 chips RAM on the BE75 PCB:


[Attachment 91100 - Click to enlarge]

[aramkolt]

Aren't those chips most likely for the FPGA rather than the Analog Devices chips though? Usually you want the ram as close as possible to the chip using them. The FPGA no doubt handles the frame TBC part, just not sure why the TBS800 behaves differently than the BE75 when it comes to line stabilization if they both are using ADLLT.

[dellsam34]

The digital processing should be part of the FPGA architecture like a RAM in a personal computer. The BE75 and TBS800 should not be drastically different, the implementation of the ADLLT maybe different, that's why line timing is more pronounced in the TBS800 compared to the BE75.

[pandy]

Nowadays is nothing unusual to use single IC with integrated multiple dies and one of them may be DRAM chip - there are various approaches to this: Chip-on-Board, (CoB), Multi-Chip Packages (MCP), Package on Package (PoP) - this is probably not the case for analog video solutions but still possible (albeit i doubt is there any new development on this area for analog video) anyway still technology progress was so huge that large embedded SRAM is feasible (1MiB of SRAM is more than enough to store 2 video fields).

[aramkolt]

Agree that they may have integrated the RAM on some ADLLT-containing chips. Even so, the manufacturers may have had to enable the features that we'd care about. I know for the DEV boards that there is some configuration required for best results for laserdisc.