GreenAntz RGB to component transcoder

[net_terminal_gene]

Posting a review because Andrew (Zebidee) absolutely deserves it.

I picked up a GreenAntz v1.95 to run VGA/RGBHV → Component (YPbPr) for Batocera-CRT-Script into a consumer CRT (Philips 20PT6341/37). The results are exactly what I was hoping for. Excellent color saturation and depth (not washed out like some transcoders), a clean image, and rock-solid sync. Once dialed in, it just works.

I did end up discovering that my first unit was faulty. After a few hours of runtime, the image would start to flicker and eventually become unstable. What really stood out, though, was how Andrew handled it. He was prompt, patient, and genuinely invested in figuring out what was going on. We went through power, sync, and environmental variables together, and he did a great job explaining the possible causes in clear, technical terms without hand-waving.

Once he identified the root cause (a build-related issue on the PCB), he didn’t hesitate. He built and thoroughly tested a replacement unit, ran it for extended periods to confirm stability, and shipped it out. The replacement has now been running 100% stable for me with zero issues.

This kind of transparency, communication, and follow-through is rare, especially with small-run hardware projects. Andrew clearly stands behind his work and cares about the community and the product. I wouldn’t hesitate to recommend GreenAntz to anyone looking for a high-quality VGA to component solution. 

[Zebidee]

Thank you Mikey! So glad the replacement is working out right for you.

Turns out the issue was caused by me not properly cutting a tiny bit of trace beneath the blue sync LED. GreenAntz is in continuous development and the boards I've been using were never designed to have a sync LED, I it is retrofitted into the design. When I get some new boards done the sync LED will be incorporated as a standard feature, no hacking required.

Now that they have the sync LED, I find it invaluable for troubleshooting setups.

OTHER NEWS

The latest design (v1.95) restores the slide switch to select between Csync and Vsync inputs! I had removed the switch for v1.94 as I was happy with GreenAntz "autoswitching" to composite sync when there is no Vsync present, I deemed it unnecessary. Unfortunately CRT_emulator does *NOT* turn off Vsync signal when composite sync is enabled. As noted in my earlier post, this could potentially result in "unrecoverable" situations, requiring rebooting into safe mode and uninstalling drivers.

The restored slide switch forces composite sync mode mode when enabled (it actually disconnects the Vsync input and "blanks" it, pulls it to logic "high").

[newshrimp]

Can't wait to try this out

[Austin_MVP]

Hi! Learning about ways to use Batocera on a CRT has led me to the Discord server/GitHub page and now here.

I have an NTSC Sony Trinitron CRT with component inputs. Hoping to get a Batocera setup running on it in the not so distant future.

[metadatum]

awesome to see hardware for analog signals still being developed and improved today.

[zone72305]

This looks promising. I recently got into the CRT rabbit hole and wanted to connect my PC to the CRT without compromise. Though I'm wondering if my PC can output 240p/480i first. I have a AMD R5 200 series card on it. I'll look into that too.

[Zebidee]

A quick update:

The new GreenAntz (v2.1) will soon be available!

GreenAntz v2.1 is fully SMD (surface mount design), I've done away with the through-hole components where possible. This means is is much smaller than the old GreenAntz, about 60% or the original size, but retains all the same great features:

- accurate composite sync generation and integration into Y signal at appropriate levels
- sync autoswitching (and manual override switch also included)
- precise voltage regulation (avoid "flickery" colours).
- optimised video amplification (more consistent, right levels, fully saturated colour)
- optional low-pass filter (9.5Mhz 6-pole butterworth) available
- optional 5v landing site for innovative project applications (e.g. inside a JAMMA cab, powered by same DC PSU as game board)
- PCB-style offset legs allow screw-in mounting (ideal for arcade cabs)
- Pots to allow precise tweaking of Y, Pb & Pr outputs.




Smaller size less than 60mm wide, and about 75mm long (including jacks).


GreenAntz v2+ also includes a pot for adjusting Pb output, so now you can adjust all three video channels (Y Pb Pr) to suit your own needs and preferences. These pots adjust video OUTPUTs, rather than throttling the RGB video INPUT signals like some transcoders do. This means there is no loss of picture information.

Going to smaller size and SMD components also seems to have provided some other less obvious improvements, including less signal interference and issues like parasitics often associated with through-hole builds. My assessment of this is perhaps less scientific than I'd prefer, except to note that when it works, it usually just looks good and works as it should.

Finally, despite the reduced size and profile of GreenAntz v2+, you can still provide alternate 5v power.


 
Screw terminals (5.08mm spacing) drop right in!


The images shown in this post are all of GreenAntz v2.0, a version only used for prototyping (green PCB). I am not intending to sell any of those. These prototypes have all been hand soldered and I can attest that soldering SMD boards takes about the same time as the old through-hole boards, best part of a day. Most of that is in the setup (solder paste and placing parts), the actual soldering (mostly with hot air) doesn't take that long. Would have saved a lot of time if I'd remembered to order a stencil (for applying the solder paste).

Anyway, within a week or so, I expect to have the new GreenAntz v2.1 boards in hand.  These ones I will be selling. The v2.1 boards will come partly assembled (~80%) by pick-n-place machines at the factory. This means I can turn them around quickly and into your hands faster.

If you want to get in early to order your GreenAntz v2.1 then please send me a PM! Don't forget that you must make at least one post before sending PMs.

PS - I am also currently investigating development of some kind-of enclosure or box. Follow this thread for developments!