Canopus ADVC-300 and other TBCs to die for

[Leo E. Backman]

Hi folks,

There's been a lot of talk here about VCR TBCs, internal/external or otherwise. I've compared many pro and semi-pro TBCs to see how they cope with old, less-than-perfect video tapes. Every TBC seems to be something of its own animal when it comes to correcting VCR PB signal riddled with dropouts. Canopus ADVC-300, for instance, does a wonderful job correcting time-base errors -- if the signal is clean! On a good day, Canopus can measurably reduce video jitter by a factor of over 1000.

However, with even medium-sized tape dropouts, the ADVC-300 suddenly gets confused. I'm posting here a comparison picture of a video frame captured with Canopus and without any TBC. This dropout isn't too large to begin with as the deck's DOC circuit can mask it almost completely. Canopus, however, doesn't take kindly to that dropout, and replaces it with a large jitter spike that messes up about 6 or 7 lines of that frame, and, of course, a lot of others, too.

Cheers,

LeoB

Ps. At http://www.digiommel.fi/ you'll find a series of tech docs and videos pertaining to audio/video tape restoration (in English). I'll soon be posting three interesting docs about VCR signal quality measurements, comparison of dropout masking ability of various VHS decks, and one that compares color signal quality of Beta, DV, VHS, Video2000, Video8/Hi8 and U-matic VCRs.

I can be reached at: research@digiommel.fi

[JVRaines]

Goes to show that no TBC is a panacea. Sometimes it's best to leave it out.

[Brad]

Hmm. The ADVC-300 TBC has been regarded as useless, or worse than useless. That German review from the post I linked shows the same jitter spikes using a LaserDisc source. It's interesting to learn that the cause is a dropout.

Your doc about the U-Matic Y/C mod was a neat read. I'm excited to check out the upcoming articles you mentioned.

[Leo E. Backman]

Hmm. The ADVC-300 TBC has been regarded as useless, or worse than useless. That German review from the post I linked shows the same jitter spikes using a LaserDisc source. It's interesting to learn that the cause is a dropout.

I have jitter measurements of the ADVC-300, that are very favorable to it. I'll try to find it. My only Canopus complaint is that its DNR process cannot be bypassed, only set to minimal values which is still too much.
Where can I find that German review? I have one made by a Japanese guy, who compared ADVC-300 to Edirol's VCM-1 (Roland).

BR,

LeoB

[Leo E. Backman]

Goes to show that no TBC is a panacea. Sometimes it's best to leave it out.

I concur.

LeoB

[Brad]

Where can I find that German review?

It's linked from the post that I linked above. http://www.ciao.de/Canopus_ADVC_300__Test_8585017

[Leo E. Backman]

Where can I find that German review?

It's linked from the post that I linked above. http://www.ciao.de/Canopus_ADVC_300__Test_8585017

Hi,

Got it, thanks.

I just noticed the ADVC-300 has been a topic here before. Even the Japanese review is mentioned. I once measured my Canopus with a Rohde&Schwarz VSA video analyzer. I first recorded jitter test signal with Panasonic AG-7330 and played it back on JVC BR-6600EG, both semi-pro decks without TBC. Here's the result. As you can see, the Canopus reduces jitter by more 1300 times to about 1.3 ns which is suberb -- as long as there are no dropouts! I wish I could get my hands on the ADVC-300 schematics.

[jagabo]

As you can see, the Canopus reduces jitter by more 1300 times to about 1.3 ns which is suberb

That's the timing of the horizontal sync pulses. Nobody is saying it doesn't output perfect horizontal and vertical sync. The problem is the video content of the scanlines isn't cleaned up much -- as far as the horizontal jitter is concerned. Ie, it doesn't fix the picture. This is easily seen in all the sample images people have posted.

[JVRaines]

The problem is the video content of the scanlines isn't cleaned up much -- as far as the horizontal jitter is concerned.

That's because the ADVC-300 contains a frame synchronizer, not a line-oriented TBC. My AVT-8710, which is also a frame sync, actually does a better job with wiggly lines than the 300 that I had briefly.

Your doc about the U-Matic Y/C mod was a neat read. I'm excited to check out the upcoming articles you mentioned.

I managed to snag a DPS-210 transcoder a couple of years ago and built a custom cable to hook it up to my U-matic deck. The improvement over the composite output is substantial.

[Brad]

That's because the ADVC-300 contains a frame synchronizer, not a line-oriented TBC.

It uses the Panasonic MN673744 chip just like the Roland VMC-1 and some of Panasonic's DVD recorders, so it's a mystery why those correct jitter while the ADVC-300 fails.

[lordsmurf]

Canopus DV boxes don't have TBCs inside. Regardless of claims, whatever circuitry exists, it does nothing.

B&H has especially always pissed me off for perpetuating that myth.

And then the 300 model's NR can't be turned off. It ruins tape quality even worse than DV alone (NTSC) already does. It adds more artifacts and noise.

It's an overpriced POS. I hate that so many continue to be duped by Canopus marketing. And it's been a decade since Canopus was swallowed by Grass Valley, and the 300 model discontinued. That piece of crap simply will not die.

[pippas]

It uses the Panasonic MN673744 chip just like the Roland VMC-1 and some of Panasonic's DVD recorders, so it's a mystery why those correct jitter while the ADVC-300 fails.

Interesting to see the Panasonic datasheet for the MN673744 chip shows both a TBC and a frame synchroniser within the block diagram.
There have been several threads over the years about how effective - or not - adding a Panasonic DVD recorder into a VHS capture input chain actually is, and what they actually do
Some posters have claimed outright that there is no TBC involved, only a rather less specific 'frame synchroniser'.... other folk seem less sure...

I use an old Panansonic DMR E55 recorder in my analogue capture path, and find it very effective. That particular unit uses a different video processing device - the MN85573 - and although I have not been able to find a datasheet for that device (so far) the DMR E55 service manual schematic clearly shows separate TBC and a frame synchroniser 'blocks' within the MN85573 device....
As I say, I find it a very useful addition to the signal path...

I've been using my Canopus ADVC50 for over 10 years now, and still find it quite satisfactory for capturing old VHS tapes, and even as a simple way to record from my PVR on occasion. The locked audio is a very useful feature, and being in PAL land, I don't find the captured DV quality too bad at all. The split between those who like - and those who dislike - the Canopus boxes seems to carry on much as it always has done ....I think those of us in PAL land might get slightly better results..

In addition, the older Canopus boxes like the ADVC50 and 100 include the option to overcome the 'variable brightness' problem introduced by some commercial tapes. Now whether that utilised some form of TBC within the ADVC device, I'm not sure?... The later boxes did not include that option.

One problem that the DMR-E55 and DMR-E85 Panasonic DVD recorders do have is the common failure of a particular voltage regulator, due to inadequate heat-sinking. The chip itself is easy enough to find - and quite cheap - so there are probably quite few 'faulty' examples of those models that could be picked up for a very little money, and repaired easily, to be returned into service as cheap TBCs and frame synchronisers for assisting with VHS capture.....
..Assuming they haven't been actually been thrown away already of course....

[SameSelf]

Canopus DV boxes don't have TBCs inside. Regardless of claims, whatever circuitry exists, it does nothing.

B&H has especially always pissed me off for perpetuating that myth.

And then the 300 model's NR can't be turned off. It ruins tape quality even worse than DV alone (NTSC) already does. It adds more artifacts and noise.

It's an overpriced POS. I hate that so many continue to be duped by Canopus marketing. And it's been a decade since Canopus was swallowed by Grass Valley, and the 300 model discontinued. That piece of crap simply will not die.

Whoa! Hold on there. So a 10-year old device that does a job well, albeit not to your esoteric, slavish demands, is nothing more than "an over-priced POS"? You must be grumpy smurf.

[Skiller]

Wait, you are missing a vital detail here, SameSelf: pippas has been using the ADVC-50 for 10 years with good results while lordsmurf was ranting about the ADVC-300. That's a big difference. The ADVC-50 doesn't have any aggressive and undefeatable NR and a non-functional or even destructive TBC like the 300!

I too think the ADVC-50 is OK and the ADVC-300 is a huge POS, lordsmurf hit it well.

[SameSelf]

You need to slow your roll, dude. I didn't miss any vital details. I have owned an ADVC-300 for the last ten years. Grumpy smurf's rant about it is simply childish. Like I already said, maybe it doesn't fulfill his/your esoteric, slavish demands, but it gets the job done and even works in Windows 10. Not bad for a 10-year old legacy device originally designed for XP.

[lordsmurf]

You need to slow your roll, dude. I didn't miss any vital details. I have owned an ADVC-300 for the last ten years. Grumpy smurf's rant about it is simply childish. Like I already said, maybe it doesn't fulfill his/your esoteric, slavish demands, but it gets the job done and even works in Windows 10. Not bad for a 10-year old legacy device originally designed for XP.

My description is accurate.
Your dismissiveness of the huge flaw is what's childish.

The 50//55/100/110 are low-quality DV devices (for NTSC), and damage NTSC color (4:1:1).
Then the 300 goes one further, and entirely screws up the image with wonky "NR" that creates artifacts.
If you must use DV, then at least avoid the 300.
PAL 50/55/100/110 is fine (4:2:0), the 300 is still bad.

The ATI 600 USB works in Windows 10, and allows both MPEG and lossless capturing. If you want quality, get that.
A few non-EZcap(crap) Empia chipset USB sticks work nicely, too.

[Skiller]

You need to slow your roll, dude. I didn't miss any vital details.

Since you did not mention it up to this point, it was not clear you were talking about a 300, even one that you used for 10 years yourself – it seems naturally you were responding to pippas experience, also 10 years, with the ADVC-55 while lordsmurf referred to the 300. That was the vital detail you were missing from my point of view.
So maybe you did indeed not miss any vital details, but from what you've written it sure seemed like it.

Not bad for a 10-year old legacy device originally designed for XP.

It's a Firewire device; it's needless to say it's compatible with Windows 10. Any Firewire device is.


Let's just leave it this way, different people have different needs. If "getting the job just done" is all you wish the ADVC is quite good, although even then I still wouldn't ever recommend the 300.
It's not just lordsmurf, the 300 wouldn't fulfill my "esoteric, slavish demands" either and tbh I can't see why that particular one would for anybody else. Just my opinion.

[SameSelf]

Your dismissiveness of the huge flaw is what's childish.

The only thing I am dismissing is your childish logic that this "huge flaw" equates to an "overpriced POS".

[lordsmurf]

What amazes me is that you've started and participated in some above-average threads about lossless, color, etc...
... then you use a known-flawed device to capture.

You can't have it both ways.

[SameSelf]

Now you're just not making any sense. Making this about me is a classless, troll-like move. If you have a beef with my other threads, post it there. Look, I know you have been a well respected member of this forum for many years. But when I see someone like the OP start an very informative thread such as this, only to have an esteemed member like yourself come on here to trash their efforts, it stinks of trolling and the hive mind atmosphere that permeates VH and doom9.

[lordsmurf]

You try to start fights on VH: https://forum.videohelp.com/threads/379772-Response-to-closed-thread?p=2454587#post2454587
And I'm a troll?

Okay then.

[SameSelf]

It's an overpriced POS...That piece of crap simply will not die.

You try to start fights on VH

Sounds like your talking to yourself

[digicube]

That's because the ADVC-300 contains a frame synchronizer, not a line-oriented TBC.

Really? Users on Grass Valley forums say it's a line TBC because it cleans up wavy images like a JVC SVHS VCR. What I don't understand is that if you connect a full frame TBC to ADVC300, it no longer corrects the wavy images.