MOD GUIDE - Universal RGB-to-YPbPr/Component Circuit & Mod [8/24/2014]

[Keith Courage]

I have one TV that displays the picture slightly darker than its other inputs using this component mod. However, it is brighter on my other TV sets so the issue could be how your TV accepts the signal.

Have you tried it on any other Televisions?

[lastcallhall]

It's on my to do list. My concern is that I've used a different component circuit on the Genesis/SMS with the same TV im using now, and the colors are noticeably brighter between the two circuits, so unless the TV is sensitive to the output driven from the R-Y and B-Y outs, im not entirely convinced that it's the tv. But yeah, I plan on trying it on another set tonight.

[lastcallhall]

Turbokon circuit:




(Sorry about the blurriness!)




Ace/Helder Amp:







I want to be clear, here: I don't think the amps are faulty in any way - they work fine on the Turbo stuff. I just don't know what's going on when I connect them to a non-Turbo console...

[NightWolve]

Ace used a professional RGB Encoder IC (the BA7230LS) I believe, if it's the same guy I'm thinking of, and Steve's circuit design is something you can build from off-shelf RadioShack parts, 2n3904 transistors, caps, resistors and a diode, etc. Transistor video buffer amps/drivers will never perform as well as specialized ICs (likely with internal op-amps) that convert RGB-to-YPbPr. The thing about Steve's circuit is that anyone with some solder skills can build it and cheaply (shopping via eBay!). Not crazy about the pricing of turbo's boards built on the free design, but the full circuit is freely shown here for all of us Do-It-Yourselfers out there (unlike say JROK), so something to consider as far as pros/cons...

Actually, Ace is a cool guy and also released his circuit design, but you gotta buy a custom IC, that BA7230LS chip. Here goes for others:

[lastcallhall]

It's a BA7230LS - I have ~100 of them sitting on my bench. It's just a video encoder. You can get them for a dollar or so if you buy a lot of them (which is how I wound up with ~100 of them)...

I know im being a pain in the ass wanting to get the circuit to work for something other than the Turbo stuff, but I'm really interested in the circuit's output, especially based on the pics that TK put on his thread. The output looks crystal clear, and no jailbars, which is the seller for me. Ace's design still has jailbars on the Model 1 Gennys and the Master Systems. If I can get a clear pic out of the TK board, then Im all for trying to figure this out. I just have no idea where to start...

[NightWolve]

Hm, maybe I'll hit you up and buy a 5 pack off of ya.

[poponon]

There was a newer version released recently:



I'm also interested in grabbing some of those BA7230LS

[lastcallhall]

RE: Ace's circuit. That's a really old design. Here's the current design:



I actually just made a board through OSHPark today that got sent off to fabrication:



In a few weeks I hope to see how they turn out, as I've been using an older design prior to today.

[NightWolve]

Well, that appears to be when you can't obtain a clean source of the H/V Sync, so instead you tap the Composite output and it thus requires buying a Sync stripper. I don't need that, but yeah, others might, so might as well include it here. Is there an update without the stripper ? I'll edit it into my earlier post.

[lastcallhall]

He started adding the LM1881 in version 2.0.

[thesteve]

i wonder how the power usage compares?

[thesteve]

another note, i know the TK board (my circuit) can do better then that on the genesis
during the circuit redesign i was switching between un-amped PCE and GENI SCART for my input
had good results with 75ohm and 220uf in the scart cable and 75ohm to ground after the cable

[MotherGunner]

Now if only rid the TG-16 of jailbars once and for all?

[turbokon]

lastcallhall, I'm curious as why yours as so dark. 

Ace used a professional RGB Encoder IC (the BA7230LS) I believe, if it's the same guy I'm thinking of, and Steve's circuit design is something you can build from off-shelf RadioShack parts, 2n3904 transistors, caps, resistors and a diode, etc. Transistor video buffer amps/drivers will never perform as well as specialized ICs (likely with internal op-amps) that convert RGB-to-YPbPr. The thing about Steve's circuit is that anyone with some solder skills can build it and cheaply (shopping via eBay!). Not crazy about the pricing of turbo's boards built on the free design, but the full circuit is freely shown here for all of us Do-It-Yourselfers out there (unlike say JROK), so something to consider as far as pros/cons...

Actually, Ace is a cool guy and also released his circuit design, but you gotta buy a custom IC, that BA7230LS chip. Here goes for others:

night, I would have to disagree with you my friend. Just because you have some soldering skill, doesn't mean you can build the board easily using thesteve's circuit design.  I know I had a heck of a time building the prototype.  Good to do it once that's it.  Even with the prefab boards, still takes a lot of time to put one together, very tedious, all done by hand.  With that, I think my pricing is fair.

[turbokon]

Lastcallhal, where are you getting your signals from?  I tapped every signals off the CXA1145 chip on a model 1 genesis.  I'm still using version 1 component board.