Hm, that's a great price for circuit, fancy enclosed box to boot, plus S-Video support! Great find!
I'd bet it uses an IC so it's likely better than Steve's basic transistor design (
used by turbokon's boards), but for that price it likely isn't as good as say something like the JROK Video encoder (
http://www.jrok.com/hardware/RGB.html ) which is in the $65-$85 now. Speculation on the latter part, so who knows, but if it's using a cheap chip like that BA7230LS (factory made for RGB-to-YPbPr), it will definitely perform better than the fan design by Steve of a bunch of transistors put together and so forth.
In short, could be a really good deal and worth checking out for comparison! Note: This is just about simple encoding, no tricks like resolution doubling (AKA upscaling) from 240p to 480p or something which would ensure that the YPbPr signal will work with all modern LCD TVs. The circuits shown here on PCEFX thanks to Steve,
Ace's circuit on sega16, and definitely this box (because of how cheap it is), are just for simple encoding and you have to hope that your modern LCD TV accepts a 240p signal via the green Luma/Y jack!
EDIT:
http://www.ebay.com/itm/RGB-SCART-to-Composite-COMPONENT-VIDEO-AV-TV-ADAPTER-HD-CONVERTER-/220833672632?pt=LH_DefaultDomain_2&hash=item336ab66db8So that's interesting, more cost-effective solutions out there now if you're willing to tap your RGB lines, convert to SCART and buy a SCART cable to connect inbetween (then go to YPbPr)! As cheap as these newer encoders are, you can take a few risks and see what's good or not, etc.
hack a TV to accept RGB (http://mikejmoffitt.com/wp/?p=284).
Ah, that's awesome Mike worked on that! Though I'm hoping somebody does it via the 3 RGB lines that go to the neckboard of the CRT (how I did my tests) as that mod technique will be able to provide the most universal results (
comes with drawbacks however, no control of contrast, tint, color, etc., but the advantage is you don't have to rely on a lucky TV with chip exposing RGB inputs on the motherboard and need of service manual to figure out if you've got a chance with the particular TV, etc.).
I got beautiful results with my SNES and 2 small TVs I tried, but since I'm not an EE like Steve, I can't come up the proper way to terminate those lines for general acceptance of other RGB signals and what not. Dunno how to design the most "proper" and *safe* input circuit essentially, though I can get it to work with my SNES at present. Color saturation will be perfect, but dependent on the system/console. Tint will be perfect as well (all 3 RGB lines, same signal strength, direct to the electron guns, no tweaking, yield a centered tint), and brightness can be handled by the pot at the flyback transformer... Only thing is no contrast control, but with the RGB signal tuned by the system/console, I just didn't have any complaint with the results! But yeah, it's much better if you can do it the way Mike does it with his example. It's just harder, might not be possible with a % of TVs and you will need to find the service manual.