MOD GUIDE - Universal RGB-to-YPbPr/Component Circuit & Mod (8/24/2014)

[ConHuevos]

In Vp-p?  If you have tools to measure impedance I'd appreciate the approximate amounts.  If they are indeed higher than .77Vp-p I'll need to use a divider to drop them down.

[Keith Courage]

Well I am sure hoping this is going to be my last component mod problem. Anyways, I have installed the component board in a DUO. I even installed the two 22UF capacitors for the jail bar fix but the jail bars are still present. Now here is the interesting part. This DUO also has an 8PDT switch installed for a region mod. Well, if I touch the wires on the 8PDT switch the jail bars disappear. Any idea how to fix this problem? I already tried running a ground wire a wrapping it around the wires for the 8PDT switch and that did nothing. Only when I touch the wires do the jail bars go away.

[thesteve]

keith its a wire routing issue
caps to ground couls solve it and cause game glitches

[thesteve]

Anyone know the impedance for the RGB lines coming off the 6260 by chance?

the lines are running open stock
the outputs that are used are running into approx 1K loads

[Keith Courage]

You were right thesteve. It was a wiring routing issue. I didn't even consider it because none of the wires were even close to touching one another before when the problem was present.

[turbokon]

Glad you solved the problem Keith.

Also, thesteve said this design should work for all rgb enabled systems by adding three 1kohm resistor to the rgb signals. Thesteve and I installed the component video boards with the additional resistors in our genni and its works flawlessly.

[ConHuevos]

Is the last schematic posted the latest version or have there been updates?  If so, can you post them?

[thesteve]

the schematic is correct in the first post

all the caps are now 22uf ceramic

[ConHuevos]

Awesome thanks, currently making a board in Eagle to send to oshpark .

Oh nevermind...read your post in the sales section.

Turbokon really should edit his post as he is generalizing that all other console will only require 1k extra resistance on the RGB inputs, when it's impedance dependent.

[turbokon]

Awesome thanks, currently making a board in Eagle to send to oshpark .

Oh nevermind...read your post in the sales section.

Turbokon really should edit his post as he is generalizing that all other console will only require 1k extra resistance on the RGB inputs, when it's impedance dependent.

Thesteve, correct me if I'm wrong, the 1kohm resistors are needed to help with the offset voltage cause by the genni's rgb lines outputting at a higher voltage then the pce. Impedance is something different, is the ratio of voltage to current in a ac circuit. This design operates in a dc, so impedance and resistance are the same. Theoretically, the additional 1kohm resistance should work with other rgb systems.

[ConHuevos]

Awesome thanks, currently making a board in Eagle to send to oshpark .

Oh nevermind...read your post in the sales section.

Turbokon really should edit his post as he is generalizing that all other console will only require 1k extra resistance on the RGB inputs, when it's impedance dependent.

Thesteve, correct me if I'm wrong, the 1kohm resistors are needed to help with the offset voltage cause by the genni's rgb lines outputting at a higher voltage then the pce. Impedance is something different, is the ratio of voltage to current in a ac circuit. This design operates in a dc, so impedance and resistance are the same. Theoretically, the additional 1kohm resistance should work with other rgb systems.

I'm curious about your design Turbokon, I notice thesteve's schematic on the front says 1K off the B, R lines, and 1K on the sync.  But on your PCB  you're using 2K on the R,B, 1K for G and 510 Ohm on the sync.

I can't tell from your genesis picture...but you added another resistor to the board, which is an additional 1K  on RGB?  So are you using 3K Ohm's off the R, B lines and 2K on G with the genesis?

[thesteve]

the resistors on the board stay the same, as they are for signal mixing balance
the PCE outputs the RGB signals at the desired 0.7V output spec expected by monitors and my circuit
the geni outputs double voltage as its expecting 75ohm resistors on the outputs to feed 75ohm loads

[thesteve]

snes working
same setup as geni

[MotherGunner]

Hi Everyone, just wanted to thank turbokon for his wonderful mod work!  He did an LED, component, S-Video, and audio jack mod on my system.

My son absolutely loves playing and I am happy with the results.  I reiterate what he says that you do need an HDTV that supports these signals.  My TV does not support the component mod well as there is a lot of noise in the blacks but the image still looks pretty good!  S-Video looks outstanding. Check out.  (Sorry about the lighting on some of these)

Component





S-Video





Will be doing more mods through turbokon when I get more hardware!

Thanks again!

[turbokon]

No problem MG:)

[ConHuevos]

Anyone else get jailbars on a snes when using this?  Weird thing is, I don't get them with my TV but through my capture card.  I know its my circuit because I don't have jailbars when I run my snes via straight rgb to my PVM or my capture card (PEXHDCAP), I put 2 decoupling caps (2x .01uF) on the 5V coming to the circuit but doesn't seem to help any.

Anyone else have this?

[ConHuevos]

Got rid of the jailbars, added a 220uF and a 0.1uF bypass caps between 5v and GND on the circuit.

[turbokon]

Got rid of the jailbars, added a 220uF and a 0.1uF bypass caps between 5v and GND on the circuit.

I wonder if this will fix some of the jail bars I get on some tg16/pce with my component video boards. Do you have a pictures or diagram where you added the two caps?

[ConHuevos]

For the TG16, I put 4 bypass caps on the encoder, and then 2 on the component circuit.



I don't use a 22uF like TheSteve suggested. 1 0.1uF Ceramic and 1 220uF Aluminum can in parallel for each pin.

I tried at first with just 0.1uF bypasses on the circuit and encoder but I still had bars.  I noticed on my oscilloscope I was getting some noise on the vcc line so I added the 220uF's in parallel with them, it got rid of them and reduced the noise greatly.


Then just put a 0.1uF and 220uF in parallel between your vcc and GND input on the circuit.

Screenshots using my PEXHDCAP to capture the Component:




It looks amazing on my CRT.

Big thanks to TheSteve for creating this circuit, it's great!

[MotherGunner]

Turbo, I can send mine back.  >=]

[turbokon]

Sure mother, you bet:)

Yeah, thesteve is awesome, without him, most of the mods wouldn't be possible.

[turbokon]

I wonder if just adding the two caps to the component board will be sufficient enough to reduce the jail bars.  It will be benificial for component video installation in the ifu, dock or booster.

[thesteve]

Look up coupling caps, or stiffening caps (same thing)
The shorter the wires the less its needed 2

[turbokon]

I just added a 220uf cap to the component video board in a pc-engine with bad jail issues before, now I don't notices any jailbars.  I didn't have to add any other caps.

[Helder]

Awesome thanks, currently making a board in Eagle to send to oshpark .

Oh nevermind...read your post in the sales section.

Turbokon really should edit his post as he is generalizing that all other console will only require 1k extra resistance on the RGB inputs, when it's impedance dependent.

Thesteve, correct me if I'm wrong, the 1kohm resistors are needed to help with the offset voltage cause by the genni's rgb lines outputting at a higher voltage then the pce. Impedance is something different, is the ratio of voltage to current in a ac circuit. This design operates in a dc, so impedance and resistance are the same. Theoretically, the additional 1kohm resistance should work with other rgb systems.

I'm curious about your design Turbokon, I notice thesteve's schematic on the front says 1K off the B, R lines, and 1K on the sync.  But on your PCB  you're using 2K on the R,B, 1K for G and 510 Ohm on the sync.

I can't tell from your genesis picture...but you added another resistor to the board, which is an additional 1K  on RGB?  So are you using 3K Ohm's off the R, B lines and 2K on G with the genesis?

Turbokon could you post the current Schematic since the first post doesn't have the correct caps or resistor values that you're obviously using in your design and what value trim pots are replacing what in the schematic.
I'm trying to get this to work on a Saturn and it does work but green is too strong and the colors are off a bit, I have a 100ohm trim pot in the Y output but that only brightens the image.

[NightWolve]

Turbokon could you post the current Schematic since the first post doesn't have the correct caps or resistor values that you're obviously using in your design and what value trim pots are replacing what in the schematic. I'm trying to get this to work on a Saturn and it does work but green is too strong and the colors are off a bit, I have a 100ohm trim pot in the Y output but that only brightens the image.

Steve says the OP schematic is correct, except all cap values are 22 uF ceramic and that's good enough (That'll let you make a smaller board, no big 220/470 uF caps). Anyway, you're trying to use this design for a Saturn and so the source RGB signal is not gonna be quite the same. Like the Genesis, it's going to require some fiddling. I dunno about ole turbokon revealing any changes he made as he's selling a factory-made PCB of it. ;) But from what I can tell via the photo of his PCB, he used 10k pots for R4 and R6, those 6.5k resistors, making that aspect adjustable. So there's that, and I'd say you'd want to add extra resistance to your Green line as well given your particular case.

[Duo_R]

for universal setup perhaps some pots could be implemented? I know each of my systems RGB always needed a little adjustment to look right. As Wolf stated they are all a little different.

[Helder]

I had some oddball things happen and I had sync but colors were whack then after adding pots the image got a little better but my connections weren't great so I couldn't make proper adjustments.
My blue wouldn't do much when I tweaked it and then I noticed I had a 5v wire come loose that goes to the 22uf cap on the blue line and once I put that back the colors came out strong again instead of dull and almost black and white.
The only issue I have now is the SYNC which is making the screen jump, I had been using the Composite video and sync and was working fine but now it doesn't and the Saturn does have a Sync pin which I also used but its still not keeping the image stable.
So does anyone have any idea what to do to the Sync part of the circuit to stabilize the image without using a LM1881 which I do have but would like to avoid it since it was working fine not too long ago. I didn't touch anything on the Sync part of the circuit.

[turbokon]

Here is the layout for my boards.

[turbokon]

This boards works with the SNES/genesis by adding 1kohm resistors to the rgb signals. May just need to play around with the rgb resistors value for the Saturn. I will test with pots to see if they will work universally.

[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)

[PCEngineHell]

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.

[PCEngineHell]

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.

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 2

[Sensato Kuro]

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

TurboGrafx 16 composite vs component comparison ( YS I & II, Lords of Thunder)

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.

[Sensato Kuro]

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

Sure! No problem about that.

[PCEngineHell]

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 fuck with this more later down the road and post an update when I do.

[PCEngineHell]

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  2

[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.pcengine-fx.com/forums/index.php?topic=14876.msg320310#msg320310

[bishopcruz]

ConHuevos described it best here :


https://www.pcengine-fx.com/forums/index.php?topic=14876.msg320310#msg320310

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.

[8bitForLife]

Hi long time no see I was the original ginny pig for this mod. Has there been any advances since mine was done should I send my turbo duo rx to someone my rca jacks arent green blue red which is an ocd thing for me also lol. I think it was all he had at the time.

Second question is it still possible to put rgb on my turbo duo rx I plan on getting a xrgb mini with tax returns.

[thesteve]

Yes RGB can still be done
The color has been improved a bit 2

[thesteve]

improved compatibility and 0V offset on Y

Lastest:

[NightWolve]

OP updated! Good man steve! So 470 μF DC filter cap on our Luma/Y line, check, and now 7 transistors even. I tweaked your schematic a bit right quick, squished it to fit without horizontal scrolling, added credits, etc. Some day I promise to make it all pretty like my unfinished SNES stuff to help make it more easier to read for the masses. ;) Want it to look as pretty as say this:

[thesteve]

220Uf is considered ok, but 470UF is the standard
I also changed my luma input cap to 470UF as I wasn't happy will the Luma sag I was getting on my scope