What is a TBC? Time Base Correction for Videotapes
Timebase Corrector (TBC) FAQ
A 'timebase corrector' or 'time base corrector' -- often simply referred to as a 'TBC' -- is a device that corrects the signal and/or image quality of video tapes, especially VHS and S-VHS tapes. By the most basic definition, video is input into a buffer, and then it is corrected before being output again. However, the term "TBC" is often used so loosely, that it seems any type of "correction" can apply. There is no universal or standardized definition, so product makers can get away with calling anything a TBC. Sometimes I wonder if my toaster has a TBC. The best way to define a TBC is by empirical analysis of devices that exist, and claim to have a TBC inside, and analyzing what they do. Quick link: Listing of popular and commonly available TBCs; includes pricing and misc usage notes. Standalone, External Full-Frame TBC: A good recent-era standalone external time base corrector will:
Good standalone TBCs include:
Update: After reading this first post, scroll further down the page, and read extended information in post #3, concerning current standalone TBCs. Addendum: If you're looking for repair information on the AVT-8710 (aka CTB-100) units, a photo gallery of images is at http://www.digitalfaq.com/forum/vide...-8710-tbc.html ... it shows both the inside components, and shots of the power supply specs. The images come from a known-working unit with zero flaws. S-VHS VCR Line TBC: Found in commonly suggested VCRs, but unlike the standalone TBC, this type of timebase corrector will:
The quality of the TBC really depends on the model and line/series of the deck. In many cases, the oldest "professional" VCRs (used in studios and hospitals) are worthless crap, as compared to late 90s and early 2000s professional and prosumer models that work much better. The older VCRs were geared towards recording quality, while the latter generations of VCRs were made with playback in mind, especially that of analog-to-digital conversion workflows. A trivia worth mentioning is that the Panasonic AG-1980P comes with a "full field" TBC, which is not the same as a full-frame TBC. It's more like multiple lines of correction, instead of single-line correction. However, it is not superior (simply due to having extra lines) to the single-line TBCs found in the higher-end JVC S-VHS VCRs. JVC and Panasonic are fairly identical in TBC performance, with the main differences in these VCRs being the transports, and how each reacts to tapes (based on the recording mode and content of the tape). DVD Recorder 'TBC': This is where we start to enter the land of "it's a TBC because we wrote it on the box". In many cases, the "TBC" is nothing more than a basic frame sychronizer, or circuitry that provides a similar function. Several manufacturers have referred to such circuits as a "virtual TBC"; however that's misleading, as it's not really a time base corrector, and arguably not even close to it. Most DVD recorder 'TBCs' will do next to nothing (or outright nothing) in terms of visual cleaning or signal cleaning in a positive way. At most, some DVD recorder "TBCs" have a unique ability to removing tearing (sometimes called "flagging" because the video waves like a flag in the wind). That's the error that can sometimes be seen on the top of a VHS signal, a visual distortion on the uppermost portion of the screen, due to a severe timing offset of the frame. The most famous DVD recorders capable of doing this as the Panasonic DMR-ES10 and DMR-ES15, which are also discontinued and only available via eBay, Amazon or this site's Marketplace forum. You'll have to disable the VCR TBC, as well as remove the external TBC from the workflow, in order to benefit from this feature. You may want to read this: An advanced definition of video tearing. Unfortunately these tearing-fixing DVD recorders often have bad capture/recording quality, so you'll want to use it in "passthrough" mode. This means you feed a signal into the DVD recorder, and then output it to a better capture device downstream. It is not used for recording. You can usually re-add the standalone TBC after the DVD recorder, because it's still not necessarily the best analog signal yet. Remember, it's not a true TBC. Only a few select models have this unique passthrough ability. The Panasonic "ES" series from 2005-2006 is known for this (ES10, ES15, etc). The Panasonic DMR-ES10 is suggested and is still sometimes sold used/refurbished at Amazon for a about ~$200. Some DVD recorders have digital noise reduction (NR) -- integrated into the processing circuit (which include the "TBC"), like S-VHS VCR TBCs and their integrated NR circuitry -- but it can be overly strong. The ES10, for example, over-processes the video with or without the NR feature engaged, causing temporal blurring/ghosting and posterizing/banding the video (compressed color palette). Turning on the NR feature makes it stronger. For this reason, the ES10 is not suggested for use as a TBC replacement, but simply as a box used to address this specific tearing error. Remember that the goal of restoring video is to make it better, not make it perfect. Compared to tearing, overdone NR is the lesser of evils. But when the video has no tearing, no need to introduce other flaws. DV Converter Box 'TBC': Even worse than DVD recorders, the so-called "TBCs" found in DV converters generally do nothing to help with your video or signal quality.
The Canopus ADVC-300 is commonly propagandized by the manufacturer and sellers for being a box that will make your video perfect. However, it is no more or less special than any other DV converter, as observed by users. In fact, in many cases, the performance of the ADVC-300 was very poor according to users (as proven with comparison clips), due to significant overprocessing of the video. The best quality was achieved by turning off all the expensive filters. Keep in mind that these DV converter boxes are from the era of the Pentium III computer. Literally the technology of the late 1990s and early 2000s, before it was possible to easily achieve high quality uncompressed and lossless AVI capturing, as well as MPEG-2 capturing. If you still insist on using one of these DV boxes, the ADVC-300 is available used from Amazon for about $400 or eBay or our Marketplace forum. Conclusion The best advice is to stack a good S-VHS VCR (with TBC), with an external standalone frame sync TBC, to take care of both image/visual and signal quality. If you use a DVD recorder or DV box further down the line, so what -- forget it has a TBC. Or rather, forget "TBC" was written on the box. Also... If this information has been helpful, please upgrade to a Premium Member status, or consider a donation. Premium Members will get longer in-depth one-on-one help for their projects, and in the future will be able to access exclusive content. And the price is about the same as buying a book or couple of magazines -- but far more useful! Thanks. :) |
would this be a good unit its five dollars less the the other non datavideo unit mentioned above. It seems to have a solid case that should aid in the heating problems these unit have??? |
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Hi Johnny, welcome to the site. :)
To answer your question (about the linked 1T-TBC), plus add more details to this TBC FAQ thread... Cypress Technology and DataVideo are the two primary TBC manufacturers with low-cost external timebase correctors with frame synchronization. "Low cost" meaning the TBC is less than $1,000, with many Cypress and DataVideo models sometimes pricing in the $500 range. DataVideo DataVideo products At one point in time, DataVideo had several models available - TBC-100, a PCI slot card, molex powered - TBC-1000, a TBC-100 PCI card married to a VP-299 distribution amp <<< popular model! - TBC-2000, a 1990s version of TBC-3000 - TBC-3000, dual-channel, essentially two TBC-100s in a single board, with proc amp - TBC-4000, quad-channel, essentially four TBC-100s, but using a 4-way switch*, with proc amp - TBC-7000, the TBC-4000 with (useless) chroma key function - and the TBC-5000, the only not suggested model from DataVideo, as it expects studio/broadcast (non-VHS) sources. This is was made after all other DataVideo TBCs were discontinued, and has zero relation to the earlier generation of units. Many other "also include TBC" mixers, chroma keys, and other DataVideo boxes are the same as the TBC-5000 (not suggested!). * Having four TBCs in a single unit sounds nice, but the 4-way switch can cause issues while capturing. You need to set all 4 sources before the captures, and then not switch it again until all 4 are complete. But it's also not likely that you can have 4 complete workflows in such a tight space unless you have a special multi-desk or rack setup. I honestly consider the TBC-4000 to just be a TBC-1000 with a proc amp; an upgraded TBC-1000. All of the pre-2010s DataVideo TBCs essentially had a TBC-100 at the core (or multiple TBC-100 on a single board), with another device added (distribution amp, proc amp, dual TBC/PA, etc), inside the standalone black metal box. Reviews for DataVideo TBCs have been mixed over the years, though usually favorable. Understand that many DataVideo TBCs looked perfect as-is, but quality from copy to copy seems to have varied. There has been user evidence online suggesting some units were soft or had vertical power line noise in the image. For example: - On the TBC-1000, defects have been shown to be caused by the VP-299 distribution amp, and not the actual TBC-100 inside the case. See attached photos at the bottom of this post, compare the VP-299 to the TBC-1000. Members at this site discovered that it can be modifies to bypass the VP-299. Instructions and photos of modified units can be found in this thread: http://www.digitalfaq.com/forum/vide...8710-vs-2.html - On the TBC-3000, the switch from jumper to DIP was sometimes important, as most DIP units look perfect, while jumper units can vary. Manuals are also available: http://www.digitalfaq.com/forum/vcr-...r-manuals.html Important: Never use a TBC without a UPS. Unlike many devices, including most VCRs, a TBC has no fuse to protect the components from power fluctuations. Flickering power can destroy a unit, and nobody is immune to power problems. Heed this advice! A good Cyperpower unit is suggested. This is probably the best TBC that you can buy, for capturing tape formats to digital. :congrats: Cypress, AVToolbox and TVOne Cypress products are usually not under the Cypress name brand. The two primary models of Cypress TBCs are the CTB-100 and the 1T-TBC (and 1T-TBC-GL variant that adds genlock). Cypress Technologies in Taiwan is the designer and manufacturer of these timebase correctors, and are sold in bulk to private labels that re-brand (or "rebadge") the units with their own brandings and colored cases. CYP is the in-house brand for Cypress, and has official outlets in Asia and Europe. The CTB-100 is the lower priced of the two TBCs, and often considered to be of extremely high quality (when it doesn't have defective chipsets, at least!) This specific model is best known as the AVT-8710 in North America, as sold by TVOne (formerly AVToolbox). On eBay and in Europe, it's often sold under any number of model numbers -- usually CTB-100, TCB-100, AVT-8710, TBC-100. See attached photos, showing variant CTB-100 models. The 1T-TBC/GL and CTB-100/AVT-8710), share the same main circuit board, according to TVOne support. However, the boards appear different. But the units do, at very least, contain the same IC chips. So the AVT-8710 is essentially the same as the 1T-TBC. All of these units are affected by the infamous bad chipsets in all units manufactured during the 2010s (2010-2018), which cause severe ghosting and frame-locking/sticking from defective IC buffers. Warning: Unlike the simple "green vs. black" casing for an AVT-8710, the 1T-TBCs have never changed appearance. The 100/8710 had a recessed area where the serial label was affixed, but the 1T-TBC did not. For that reason, many 1T-TBC units now lack visible serials. The only way to verify the unit is good is to dismantle it, and verify the board ICs. Example images: http://www.digitalfaq.com/forum/vide...html#post10238 More images and discussion: http://www.digitalfaq.com/forum/vide...s-capture.html You'll find a photo gallery of images at AVT-8710 TBC specs? It shows both the inside components, and shots of the power supply specs. The images come from a known-working 2004-2006 era unit with zero flaws. Important: Sima also used the CTB-100 cases for it's non-TBC products. Do not assume anything in the case is a TBC! Some Cypress format converters used the case, and even claimed to have TBC -- but it does not work when not converting formats (PAL>NTSC, or the reverse). Important: Never use a TBC without a UPS. Unlike many devices, including most VCRs, a TBC has no fuse to protect the components from power fluctuations. Flickering power can destroy a unit, and nobody is immune to power problems. Heed this advice! A good Cyperpower unit is suggested. Important: Cypress has no on/off power switch for their TBC units. You can yank the plug from back, but it's not suggested, as it can throw sparks or harm the unit. Instead, get an inline extension cord or outlet switch, or just use an extra power strip (often falsely called "surge protectors"). Use that as the on/off switch. Like DataVideo, this is one of the best TBCs that you can get to transfer your tapes to DVD/digital formats. :salute: TBC Buyer's Guide - The Best External Timebase Correctors As of 2021, the list of suggested TBCs is as follows.
1. DataVideo TBC-100|$300| 2. DataVideo TBC-3000,4000,7000|$700+|$250+ 3. DataVideo TBC-1000|$480+|$250+ 4. AVToolbox, TVOne AVT-8710|$325|$250+ 5. Cypress CTB-100, clones|$265+|$250+ 8. Cypress, TVOne 1T-TBC|$550|$400+ 6. Kramer FC-400|$900|$400+ 7. For.A FA-125|$1500|$400+ And if it's not listed here, it's NOT recommended! This includes: - non-green era (2000s) Cypress units - rack-mount units by Leitch, DPS, Snell & Willcox, etc, that expect studio sources (not VHS, Hi8/Video8, etc) - the cheaply made noise-prone Key West Big Voodoo devices - the wanna-be/fake "filters" and "clarifiers" from Grex, Sima, and others - and (for most people), composite-only TBCs like the FA-128/130, and ancient 90s Cypress units * Note that most Cypress units, and their clones, are sold on eBay. Most of the sellers have proved to be obstinate, rude, and generally lacking of any knowledge on video (including TBCs), resulting in difficult returns (which is usually required, due to receiving a known-defective unit). Several auctions also have horribly distorted information, both with images and as text, describing the abilities of TBCs -- pure lies, as far as I'm concerned. * NOTE: Although this post was written in 2011, it rarely needs updates. Don't be one of those obnoxious people that thinks all online articles need monthly updates. This list of TBCs has not changed in several years, and can be considered "evergreen" content. At most, notes on that issue will be amended if the new products becomes discontinued, and is no longer available in stores. The rankings will not change, outside of the unlikely situation of a new product coming to market. Just so we're clear on this. Thanks. * Again, all new AVT-8710s aka CTB-100s are defective. If the model is black, do not get it. It was announced in 2018 that these known-bad TBCs will be discontinued, and this page will be updated when places like B&H stop selling them. Final Thoughts Anything not sold "in stores" will have to come from used channels. For example, the digitalFAQ.com Marketplace forum, eBay, Amazon, or Craigslist. I currently use (or have used) all of the TBC models discussed here. These external TBCs provide stable signals to the capture cards and DVD recorders, which allow for a perfect transfer experience -- no dropped frames, no signal-caused distortions. I hope this has helped expand this thread. :) If this information has been helpful, please upgrade to Premium Member status, or consider a donation. Premium Members will get longer in-depth one-on-one help for their projects, and in the future will be able to access exclusive content. And the price is about the same as buying a book or couple of magazines -- but far more useful! |
I'd like to ask a question and to comment.
The question is... Out of the external TBC you've mentioned, any model has good 3d comb filter for Y/C separation? Or TBC are not designed for that? I'd like to comment on Canopus ADVC. I know that you don't like them... :) nevertheless. 1. Only ADVC-300 has built-in LTBC. ADVC-100/110 don't and are not advertised to have LTBC. 2. I recently acquired ADVC-300 to use with not-so-important low quality old VHS tapes just to make it quick. So far I had not had any single frame dropped during my captures and that would include static/snow between clips and so forth. The only thing I experienced was disconnection during blue screen due to the fact that I was capturing in SECAM format and at the time VCR stopped, it automatically would switch into NTSC format for blue screen. So I guess in that sense LTBC is doing a pretty decent job. The TV Tuner card I have would immediately drop frames during static/snow. |
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dFAQ forum member Ghitulescu made this comment on another site: Quote:
It's just not the job of an external TBC. |
The comb filter in the AVT-8710/TBC-100 is nothing special, they claim its 2D-line. You get plenty of dot crawl with it. The comb filters in JVC SVHS decks and the Panasonic AG-1980 are of the 3D-adaptive type and produce much cleaner output without dot crawl.
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B&H is 20 minute away from where I work. Thank you. --Leonid |
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Ok, I went ahead and purchased AVToolbox AVT-8710. However, I am returning it. I've tried it with my FlyVideo LifeView 3000 TV Tuner card. I plugged the DVD player and played Snell & Wilcox reference. NTSC. The video quality between direct capture and capture via TBC was very close. The images are attached. However, I then used the SECAM VHS tape. And there I noticed that when I viewed using TBC, TBC would freeze the video frame at random from about 100-200 milliseconds up to a second or more. Yeah, I would not get the dropped frames during capture as far as my TV Tuner card is concerned, but I would get the dropped frames inside TBC. The frozen frame is a dropped frame in my book. So I had to scratch this solution.
While playing with it I noticed that my capture software has perhaps something similar to TBC. I use Philips SAA713x family card and use Philips drivers (not the LifeView ones). The application software has Vertical sync recovery modes. There are 4 modes: Normal, Fast Tracking, Free Running and Intermediate Running. Usually what I used to do is I would start capturing in Fast Tracking mode and then switch to Free Running mode. That way, I don't get any dropped frames. |
AVToolbox AVT-8710 (a Cypress CTB-100 model). How is the audio handled on a unit with no ins & outs for audio on the TCB?
After capturing it are you supposed to take the file while in the timeline, unlink the audio from the video and nudge it into place? |
TBCs only process video.
The only TBCs that have audio inputs are actually TBCs merged with distribution amps, such as the TBC-1000. The DataVideo TBC-1000, for example, is a TBC-100 inside a VP-299 distribution amp. There's no reason to nudge anything on a timeline. Audio should still be in sync. (At worst, it'll be a half frame offset.) |
Hi, lordsmurf. Any recommandation for a pro tbc unit ? Because now with some of the older posts here, I'm quite lost. Wich one of the units are the best and affordable and, it they needs modification(s), wich one(s) should we do for the best efficiency and can we get a good tutorial to do these correctly ?
Thanks to answer |
With the AV Tool AVT-8710 i believe it only comes with a 110v power adaptor for USA market. If i buy one of these TBC's can i just use any power adaptor sourced locally the right voltage and amp rating because i am not in USA and have 220-240volt mains.
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The CTB-100 would come with a power supply native to where it was sold. But the unit itself works with worldwide power standards -- you just need to get the proper plug for it. ;) |
Great thread, I'm currently looking to buy a new TBC and it's helped narrow the options down. The last one I bought was a CTB-100, which I got unlucky on and received a defective unit, with all the same problems that have been well documented here already. It's really unfortunate that the new units are defective for such a highly recommended model. I'd rather not take the risk on buying another one.
The TBC-100 looks like the best replacement, since out of the list I see there's no cases of defective units. If I'm reading correctly, the standalone TBC-1000 is, in some cases, negatively affecting the image because of the distribution amp. Therefore, is the 100 PCI model actually transparent? Or does it still have some degree of softening or otherwise affecting the image? Apart from wanting a TBC that works well, having a TBC that is transparent is important to me. One of the frustrating things about my CTB-100 is that its proc amp isn't set at neutral, it makes many of its own adjustments without me touching anything, which I consider unacceptable. I can live with an image that's a touch softer though, if the TBC has exceptional performance. I'd appreciate any feedback I can get on this, I have the option to buy a new TBC-100 and would like to know if it's currently the most reliable choice for performance and transparency. Excluding pro models that is. Thanks for your time. |
The TBC-100 is easily one of the best TBCs for transparent processing (removal of signal flaws).
The only time you may have issues with it is if the computer's power supply is "dirty" power, but you'd likely notice that problem on graphics output, capture cards and audio cards, too. (It's NOT always present on all three devices, but usually it's visible everywhere when present. The solution is to use a better power supply, not the cheap ones or "free" ones that came with a budget-grade computer.) |
With the TBC-100 because its ment for a desktop and i only have a lap top, could i mount it in a box and run it on its own 12v or whatever it needs power supply to it and basically make it into a TBC-1000 but without the distribution amp?
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I wonder if these are worth adding to the list at the start of the thread
- http://www.cypress.com.tw/english/display.asp?id=309 - http://www.cypress.com.tw/english/display.asp?id=308 Have not seen them mentioned |
Those are all the same TBC chipsets -- CTB-100, from what I've read (and seen from people taking theirs apart). It's just the CTB-100 with other stuff added, not too dissimilar from the TBC-1000 from DataVideo being a TBC-100 married to a distribution amp.
Mounting a TBC-100 into a VP-299 won't work, to make your own TBC-1000, because the power supplies are different. You can't self-make a TBC-1000 without more parts than you'll received from a TBC-100 and VP-299 alone. I've attempted to house a TBC-100 in a homemade external enclosure, but the power is too dirty. I've yet to find a clean-power 4-pin molex to AC adapter. Sadly, there really are not any PCI>external enclosures on the market, aside from a few specialty items that cost more than a TBC-1000 new. |
I understand the problem above, but i am sure there could be a way to do it. I reckon all you would need to do is replicate the power input side of the TBC1000 and then add that. As long as it does not made up of any of those surface mounted robot soldered in chips then i think it would be possible. I will buy a TBC1000 first. If thats no good then i will try a TBC100 and convert that to a external unit.
It is interesting that i have just seen photos inside 2 different TBC1000's and they are different! see the small orange PCB in this http://img155.imageshack.us/img155/8991/tbc10001.jpg well i have seen one with out it. Never seen this mentioned before. Instead of having that 3 legged item on the black heatsink (i should not what its called but my mind has gone blank) mounted with those other capacitors on that orange PCB, the photos of the one i have see has that 3 legged component on the TBC100 board where that little white plug with 2 leads is connected. Any idea what that section on the orange board is? Very interesting |
How about Kramer FC-400. Kramer seems like a respectable manufacturer, their unit is still available for a reasonable $600-700USD, specs list among else 10bit AD/DA which is a nice bonus. I've been searching high and low and cannot find anyone with real first hand experience with this Frame Sync.
In a related note, Kramer explained sync and TBCs pretty nicely in their FAQ: Quote:
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