Problem with used TBC (BVTBC8 aka Big Voodoo TBC8)
 

i got one on ebay. described as used and fully functional. i tested it over a few days and it seemed to work fine: color bars with little noise in both PAL and NTSC. No problems and good video quality feeding NTSC signal via s-video from laptop or PAL signal via composite from my old VHS-c camcorder. as soon i sat down to the real capture from PAL VHS VCR, the captured signal has chroma dropouts every several seconds 2-3 frames have no or little chroma (black and white frames). tried a few times and no change. changed to the camcorder, no problem whatsoever. what is going on?

When playing a movie, from VHS-C tape?

Then delivers the recorder no exact time-constant signal.
Remedy:
a DMR ES10 or DMR EH595 connect in the passing chain.

is possible that the camera is defective.
Usually one has more attempts as a player and, you try and take the best.
I unfortunately only PAL devices for S-VHS-C and VHS C..SP and LP.
My devices do not need any adapter.

actually full size VHS cassette. the signal is noisy (handheld camcoder, probably dirty heads) but no such problems without the TBC in series. this is weird. when i tested the TBC with a live signal from a camcoder (composite to TBC and then s-video to capture card) it gave a better picture than direct composite connection to the capture card.

Almost all used Big Voodoo TBCs (BVTBC8, etc) are broken. The same units are passed around on eBay. You never see a quality unit on there. I gave up on it years ago. Most of them come from hard-worked environments.

To know if the unit is actually good, you'd have to compare it against a known-good TBC.

It sounds like a PAL/NTSC conversion error, but I'm not sure why.
Are you perhaps capturing PAL-60 by accident?
Or is the TBC set for PAL 60? (I forget if the BV units need format to be selected.)

thanks for reply. there is no setting for PAL60. you either set to PAL50 or NTSC60. i tested it some more with different tapes and other video sources and it worked fine if the video quality was decent. i noticed that some of the chroma dropouts coincided with frame tearing and some (but not all) of those spots had blue screen when captured directly without TBC (probably damaged tape). it almost looks like the bt8x8 chip has better tolerance for bad signal than TBC (unless there is a complete loss of signal).

now, when it works, it increases contrast/brightness and removes a lot of horizontal line noise at the expense of some loss of details and some more aliasing artifacts (with VHS tapes). but, the live video from a camcoder was improved with more details.

based on my experience so far, it's not useful for my needs.

-- merged --

i thought i should update my post for the record. i found a post with similar experience: http://forum.videohelp.com/threads/3...-picture-worse

looks like TBC can make things worse when recordings are poor (home videos) and tape is degraded enough. this is contraintuitive as i thought TBC should help with any poor picture.

on the other hand, when one has a relatively good video source, my BVTBC improves noise and eliminates vertical jitter (i saw it in commercial VHS tapes) or even improve resolution (i saw it with a live composite video feed from a camcoder).

so, to say that all BVTBC are junk is incorrect so say the least.

i'm trying a different thing now. i'm buying an used panasonic NV-HS1000 PAL VCR with internal TBC. if that works, fine. if not, i'll go ahead with the capture project without TBC.

You need to read this: http://www.digitalfaq.com/forum/vide...time-base.html

internal TBC = cleans the image (visually)
external TBC = cleans the signal (allows flawless capture)
You need both.

A good Big Voodoo TBC should work quite well. The problem is the build quality seems to have sucked, and they degraded with heavy use. This unit was directly sold to studios/broadcasters, meaning most of them have the heavy use. It's not a quality unit like a DataVideo.

thanks. i'll try that when that VCR gets finally delivered. it made to my city already, but UPS is not doing saturday deliveries. :mad4:

for fun i dusted my old broken VHS-c camcoder and played some good tapes through it with and without TBC.

the TBC chokes on this bad signal and loses chroma entirely, confirming what i suspected.

BTW, can anyone recognize the nature of the camcoder problem? I'm thinking bad video head, right? it was fixed once before and failed soon after and i gave up on this, but i'm thinking now, if it is an easy fix, then maybe it's worth for the capture since most tapes were actually recorded on this very unit.

Assuming it's not the tape, yes, bad video heads is one possible cause.

i discovered something interesting and totally unexpected.

the BVTBC8 has only problems with the chroma dropout only with PAL VHS tapes recorded in LP.
no problems with recordings in SP.

on the other hand, internal TBC in the panasonic NV-HS1000 has problems (weird lines in the top of the frames) with PAL VHS tapes recorded in SP, but no problems with recordings in LP.

this is crazy! i'll post separately with some examples.

on the other hand if one skips the TBC altogether, the vertical lines are wiggly and there are blue screens (lost signal) from time to time. clearly the tapes are damaged from old age and use. also, the picture without either TBC has more noise and white clipping with loss of details in bright spots.

the 100 can output no clean time constant signal.
With internal TBC, nor with TBC = off.

As already written ... use Pana DMR ES 10 or DMR ES 15
Try times

last time i checked (locally), those were NTSC only. i need PAL. are PAL Pana DMR-ES-10 or DMR-ES-15 available in Europe?

Edit: i looked it up. the european ones are PAL/NTSC, while the USA ones are NTSC only.