Confused: Why a VCR with TBC if separate TBC needed anyway?

tluxon · Member Joined: 22 Mar 2002 Location: Kirkland, WA

I'm a little confused. I see recommendations to get a JVC S-VHS VCR with a TBC (i.e. S9800U, S9911U, etc.), but then some of the same people say you need at least a separate TBC in the $200+ range.

If I'm best off getting a separate TBC anyway, why get a VCR with TBC?

Thanks!

Tim

BrainStorm69 · Tobor Joined: 05 Aug 2002 Location: Texas, USA

So far, my experience has been that the external TBC will keep you from dropping frames, but the line TBC of the JVC vcrs correct distortions in vertical lines in the picture that are due to time base errors. My external TBC (Datavideo TBC-3000) does not correct those vertical picture distortions.

davideck · Preservationist Joined: 03 Feb 2003 Location: USA

I use an external TBC to prevent audio/video skew when capturing with my Hauppauge PVR-250. My home videos have occasional record gaps and/or dropouts which otherwise introduce a timing skew between the audio and video during the capture process.

External TBCs typically provide a continuous Black Burst Sync output at all times, even if the VCR signal drops out or is discontinuous. This guarantees clean sync to the capture device, eliminating many frame dropping and audio/video skew problems when capturing.

The internal JVC TBC does an excellent job of timebase correction. Unfortunately, it does not provide a continuous Black Burst Sync output. If the video off tape drops out or is discontinuous, then the Black Burst Sync output will also be missing or discontinuous. That is why an external TBC is often advantageous in addition to using the internal JVC TBC.

gshelley61 · Frequent Flyer Joined: 19 May 2004 Location: USA

Another great reason to get a JVC S-VHS machine with the TBC/DNR is because they provide excellent video noise reduction, especially chroma noise reduction, for your VHS tapes when playing them back. Most standalone TBC's do not have any noise reduction filters.

tluxon · Member Joined: 22 Mar 2002 Location: Kirkland, WA

Okay, what if I get a VCR with noise reduction like the Toshiba M-785 and add a standalone TBC? Will that offset the advantage of the JVC S-VHS with TBC/DNR and a standalone TBC?

BrainStorm69 · Tobor Joined: 05 Aug 2002 Location: Texas, USA

I think you will still have the time base errors that cause vertical lines to be distorted. But that is something I should test to make certain. I have a Toshiba M784 with the DNR (which is good). I'll see if I can do that sometime this weekend and post the results.

BrainStorm69 · Tobor Joined: 05 Aug 2002 Location: Texas, USA

OK, here is an example from a cap of a VHS tape with time base errors that cause distortions in vertical lines that are easy to see. First is the Toshiba M784 without any TBC. The second is the Toshiba capped through my Datavideo TBC-3000. The third is capped through my JVC HR-S9900U without the vcr's TBC (but through the Datavideo TBC-3000) and the fourth is from the JVC with the JVC's internal TBC/DNR on.

Toshiba No TBC

Toshiba with Datavideo TBC

JVC no internal TBC

JVC with internal TBC on

Notice the waviness of the vertical lines in all but the cap from the JVC with its internal TBC turned on.

tluxon · Member Joined: 22 Mar 2002 Location: Kirkland, WA

Wow, thanks brainstorm! That's pretty demonstrative of the affect of the line TBC and the full TBC. Was noise reduction tuned off in each sample?

BrainStorm69 · Tobor Joined: 05 Aug 2002 Location: Texas, USA

The Toshiba's DNR was on for both caps and the JVCs was on for the cap with its internal TBC on. In JVC VCRs, the DNR is tied to the TBC so that both are either on or off at the same time (i.e., they are not separately controllable).

mattso · Member Joined: 25 Oct 2005 Location: Australia

Wavy vertical lines or not, the clarity of the Toshiba (to my eyes) blows the JVC out of the water!

Marvingj · Posted: Jan 07, 2006 09:00

BrainStorm69, excellent demonstration!

BrainStorm69 · Tobor Joined: 05 Aug 2002 Location: Texas, USA

davideck · Preservationist Joined: 03 Feb 2003 Location: USA

BrainStorm69 -

Would it be possible for you to repeat this demonstration using the same recording for all screenshots? Preferably one that was not made on either the Toshiba or the JVC?

Timing instability is also generated during the playback process. A relative comparison between the VCRs would identify if one transport is more stable than another. For example, is the JVC introducing more timing instability during playback that it then removes with its TBC?

The noise in the JVC screenshots is much more pronounced than the Toshiba. Is the Toshiba DNR better than the JVC DNR?

You have clearly demonstrated that the JVC TBC does a good job of removing the timebase errors, but based on this set of screenshots I would capture with the Toshiba.

Wile_E · Desert Wanderer Joined: 12 Jul 2004 Location: Texas

Brainstorm, Where did you get that test pattern? Is there a high-quality version available to download somewhere? I'd like to test it with my JVC 9911 and post back my results. There have been recent posts that even the Panasonic AG-1980 has better quality than the JVC 9xxx series. Does anyone have one of these Panasonics that they could also test?

Would an EIA 1956 chart be okay to use? Maybe we could start another topic, and compare this chart on different VCR's? That would put an end to what VCR has the "best" picture quality, TBC or no TBC.
http://www.bealecorner.com/trv900/respat/#EIA1956

teeg · Member Joined: 23 Sep 2005 Location: Australia

I actually would of thought that the TBC3000 would do a better job as it is advertised as a full frame TBC than an internal JVC TBC considering that the JVC's is only a line TBC.

davideck · Preservationist Joined: 03 Feb 2003 Location: USA

teeg -

The ability to remove the timebase errors shown above requires very little memory; a few lines is more than sufficient.

The DataVideo TBCs are good frame synchronizers (in that they guarantee continuous sync to the capture device) but they don't do much in the way of actual timebase correction.

The Internal JVC TBC/DNR does a fine job of actual timebase correction, but fails to provide continuous sync. So close and yet so far.

Wile_E -

For me, the value of a capture VCR is how well it can playback tapes made on other VCRs / Camcorders.
The Panasonic AG-1980 thread was an interesting demonstration of these conditions.

I would expect all of these upper end VCRs to look good playing back their own recordings.

tluxon · Member Joined: 22 Mar 2002 Location: Kirkland, WA

davideck · Preservationist Joined: 03 Feb 2003 Location: USA

tluxon -

A lot depends upon the quality of your source tapes and your expectations.
Have you seen these?

http://forum.videohelp.com/viewtopic.php?t=287476
http://www.videohelp.com/forum/viewtopic.php?p=1381787

teeg · Member Joined: 23 Sep 2005 Location: Australia

Thanks Davideck.
Unfortunately here in Australia JVC do not produce a SVHS VCR with the good LTBCs, only http://www.jvc-australia.com/products/_products_sub_group_details.asp?ID=1364

I am only transfering good condition original copy home videos (no visible dropouts, skewing), so hopefully the TBC3000 can clean a little jitter here and there.

tluxon · Member Joined: 22 Mar 2002 Location: Kirkland, WA

All of my important material is home video on TDK-HDX tapes or Hi-8mm tapes that have been well cared-for. Will it still benefit me much to have an internal TBC?

mattso · Member Joined: 25 Oct 2005 Location: Australia

lordsmurf · Posted: Jan 08, 2006 05:52

teeg · Member Joined: 23 Sep 2005 Location: Australia

I did see those other models -- prices were extraordinary.
I'm kicking myself that I didn't buy a SR-V10E a few years ago and I understand that they are no longer made.

Anyhow, I ordered the TBC3000 last week and it should arrive tomorrow. The 6970 is expected sometime mid this week coming.

Lordsmurf: I also have a number of 8mm tapes dating back to '95. I am considering buying a Sony TRV480 Digital 8 which has a TBC and DNR. Are you aware of the quality of these features in this unit?

lordsmurf · Posted: Jan 08, 2006 06:28

I wish I had a SR-V10E. Then again, I do have a HR-S7965EK which is about the same.

8mm is beyond me. I do VHS, S-VHS, and off-air mostly.
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BrainStorm69 · Tobor Joined: 05 Aug 2002 Location: Texas, USA