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

[Helder]

Thanks for the picture, I have just about it almost figured out except I have no green. I can adjust blue and red no problem and I have sync but there is no green or little and the image is dark as hell, if I can get it to brighten up and add a bit more green it will be ok. What resistors or any other component affect green and luminance? I have made the board like the first post so it has the 220uf and 470uf and I'm using the 22uf electrolytic caps since I don't have them in ceramic. Thanks for any help you guys can give me.

[thesteve]

no green means that your luma isnt getting mixed with the R and B (or green input missing)

[ProfessorProfessorson]

Thanks for the picture, I have just about it almost figured out except I have no green. I can adjust blue and red no problem and I have sync but there is no green or little and the image is dark as hell, if I can get it to brighten up and add a bit more green it will be ok. What resistors or any other component affect green and luminance? I have made the board like the first post so it has the 220uf and 470uf and I'm using the 22uf electrolytic caps since I don't have them in ceramic. Thanks for any help you guys can give me.

This sounds somewhat familiar to the problem I am having while fiddling with this board on a MVS. I will just copy paste the PM I sent to Turbokon on here and see if, in more detail, it sounds like the same issue you are having

Ok, after adding 1 kohm resistors to the RGB lines coming off the MVS unit I honestly am not seeing too much a change. Also, I am noticing more issues then I did prior on initial testing. Maybe you ran into these issues prior when doing Snes and Genesis, so I will lay these out for you and get your input.

1. I am noticing that on some screens red and blue are fine, but on other play screens or on RGB test screen in MVS service mode that depending on what the pots are set to, Red may be missing. I can jack up the red pot to make red appear in the RGB test, but when I do that and exit out to run a game red then appears way too strong.

2.Green is also bleached out and is more or less just a light tint color on the RGB test screen. Other times it will display more greenish, but not as colorful as it should be. This was both with and without the 1kohm resistor added.

This variation in color quality/intensity affects other colors too like yellow and purple colored objects. Objects that should be a solid yellow end up appearing bleached out quite a bit or orange'ish instead.  It tends to vary from screen to screen.

Any thoughts on the above?

[turbokon]

Try lowering the resistor value coming from the green in. The board has 511ohms on it not including the 1k for the SNES/genni boards.


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[ProfessorProfessorson]

Try lowering the resistor value coming from the green in. The board has 511ohms on it not including the 1k for the SNES/genni boards.


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You know I actually considered this myself during testing and tried both with and without a 1 kohm resistor attached to the wire and just attached the green line a tad further down passing up the initial SMD resistors, but that did not fix the issue. Green still looked bleached out.

[thesteve]

Try using just green hooked to all 3 inputs, then adjust for black and white output.
Then hook your inputs back normal and test

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[Sensato Kuro]

I have just uploaded a video comparison for the RGB to YUV board (composite vs component).


Video was recorded using an XRGB Mini going to an Hauppauge! HDPVR2. I can't get the composite to look better with that setup. :/

Let me know what you think. I'm aware that the colors might be off a bit, I suck and adjusting them.

[turbokon]

Looks good sensato . With your permission I would like to add your demo video to my website.


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[Sensato Kuro]

Looks good sensato . With your permission I would like to add your demo video to my website.


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Sure! No problem about that.

[ProfessorProfessorson]

Well, gave it the old college try but sadly for me anyway, MVS is a no go with this thing. The problem is just that the color quality will not stay consistent. I ended up going to a couple of screens that have multiple vibrant colors being displayed and paused the MVS on those screens (Sam Showdown II character select screen and a couple of different stages) and adjusted on them. Colors on them looked near perfect (including yellow and green), but with the same settings I still get completely faded/bleached out colors on other screens.

Also, where blue will appear vibrant on some screens, on others like the initial NeoGeo load screen when the SNK logo appears it is colorless. This is simply either a comparability issue with the MVS itself, or it is possible it is a TV issue. Sadly I cant confirm the possibility that it is a tv issue, as the other two tv's in the house that accept component video will not work at all with this add in board and the MVS.

I still need to try this board on a Genesis here and see how it does on my tv's. If I get the same issues as on the MVS, then that will tell me at least it is a tv issue, and there is a possibility it will work fine on some TV's with a MVS at least, and just not mine. If Genesis ends up working perfect then I will know its totally a MVS compatibility issue. Will f*ck with this more later down the road and post an update when I do.

[ProfessorProfessorson]

Just an update, worked on my tv fairly fine with a Model 2 Genesis tonight, so problem I ran into so far seems to be limited to the MVS in particular in my case. I'd still need to try the other two tv's we have here to see how compatible it is , but as is nice to see it worked in the Sega on my Toshiba.

[bishopcruz]

Question about this mod, how does it look compared to RGB? I am really debating getting an XRGB-mini, or barring that a PVM, if I can find one, that being the case how does component look compared to RGB? Is it a big loss of quality going from RGB to component. The websites I was looking at say yes, but a lot of the screens in this thread look amazing.

Also, could this board work on a Saturn in theory?

[thesteve]

A few colors may not translate well, but your unlikely to notice

It is a real time encoder so no frame lag

Anything that outputs RGB 0.7V and sync should work without much work

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[turbokon]

Question about this mod, how does it look compared to RGB? I am really debating getting an XRGB-mini, or barring that a PVM, if I can find one, that being the case how does component look compared to RGB? Is it a big loss of quality going from RGB to component. The websites I was looking at say yes, but a lot of the screens in this thread look amazing.

Also, could this board work on a Saturn in theory?

ConHuevos described it best here :


https://www.pcenginefx.com/forums/index.php?topic=14876.msg320310#msg320310


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[bishopcruz]

ConHuevos described it best here :


https://www.pcenginefx.com/forums/index.php?topic=14876.msg320310#msg320310


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Ok, nice explanation. I think this really will depend on whether or not I can track down a PVM or not. Man RGB is a pain in the ass.