A TBC Tale (page 2)

When You Need a TBC

While you may not have tapes with true time base error, the sync replacement feature of a TBC may be reason enough to purchase one. Tapes shot in the slow EP speed, or tapes that are second- or third-generation copies may not have stable sync; copies may be very jumpy, or the images may flop and roll. The new sync signal that the TBC provides can restore stability to nearly unwatchable videos.

If you wish to use a video switcher that doesn't have built-in frame synchronizers (such as NewTek's Toaster), you'll need a TBC for each source VCR. However, you may not need a TBC if you use video mixers like Panasonic's WJ-AVE7 or Videonics' MX-1, because they come with built-in frame synchronizers to keep your transitions in sync. (See sidebar on video mixers with synchronizers.)

Getting Started: TBCs on Computer Cards

To fill the demand for low-cost TBCs, several manufacturers have produced TBCs on cards that plug into PC or Amiga computers. These newly developed boards are TBCs complete with synchronizers and a proc amp. Most board-level TBCs let you adjust the proc amp controls with your mouse, but some offer a more convenient remote control. Since they use your computer mostly as a power supply, the right kind of computer is all you'll need to operate them. Unfortunately, no TBC cards are made for Macintosh computers, but that may change in the near future.

For $800 list, you can get I.Den's TB Card II. It comes with a remote control and has Y/C input and output connectors. Y/C video processing is used with S-VHS and Hi8 formats to achieve high resolution and a reduction of chroma dot crawl--those annoying dots of color that look like red ants parading off your image. Ikon Video in Santa Ana, California distributes I.Den's TBCs.

Digital Processing Systems (DPS) makes the TBC-III, a card with software that goes for $850. It includes a mouse-controlled proc amp and has composite (standard video) input and output connectors. The TBC-III has Y/C connectors for input only; the output is composite. If you edit onto an S-VHS or Hi8 record VCR, spend a little more and get their TBC-IV ($999) with Y/C outputs as well as inputs.

Prime Image makes the model PCB with proc amp as well as Y/C inputs and outputs for $950. Feral Industries offers their LC 4:2:2 TBC on a card for $975 with a proc amp and Y/C inputs and outputs.

Feral also has a more advanced TBC that includes a comb filter for sharper pictures. The Feral Model A 4:2:2 lists for $1395. Nova Systems also has a card with a comb filter--the Nova Mate, which lists for $1400.

Rack-mount or Stand-alone TBCs

You may not want to have your TBC on a card. For example, if you want to move your TBC from your edit room to your duplicating room, a stand-alone TBC may be more convenient for you. You can mount stand-alone TBCs on a standard component rack, or they can just sit on a shelf. They sometimes have proc amp controls on the front panel for color correction, and some stand-alones include fade to black and freeze frame.

Digital Processing Systems makes their model 235 stand-alone for $1995 without a comb filter. For-A makes a stand-alone model FA100 with Y/C inputs and outputs but no comb filter for $2195. Feral stand-alone units generally cost $595 more than their board-based TBCs.

Hotronic makes a stand-alone TBC, the AP41, for $995. It has front-mounted proc amp controls as well as freeze frame and strobe. It has a Y/C input, but only composite outputs. For $1250, you can get their AP41SF with both Y/C input and output. Comb filtering added to all of this is available in their AP41SP for $2200.

Hotronic's new low-priced AR31 ($500) includes proc amp controls, genlock, an adaptive digital comb filter and many other high-end features. With Y/C inputs and 500 lines of resolution, it's sure to turn some heads in the consumer and prosumer markets.