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

[NightWolve]

Steve Hanleys's circuit design advanced to be more universal to work for many other consoles. But I think this thread should remain NEC specific.

* A Simple Jailbar Fix Guide has been included. Check end of this post.

* Current Revision (8/24/2014): The latest 2014 design (over the 2013) adds a 470 uF DC filter cap for Luma/Y to bring the video signal closer to video standards and help eliminate problems like screen flashes, sync dropout, etc. Many other tweaks to note also, so it's significantly different from previous designs.

RGB + H/V Sync taps from 6260 Video Encoder Chip
	Yellow is for H/V Sync, RGB pins are color matched. Exact: pin 51 - Blue pin 49 - Red pin 47 - Green pin 44 - H/V Sync

** Parts List Review (Updated: 8/24/2014) **

• Resistors (15): A $10 general 500 resistor pack should have all values needed, check eBay.
• Capacitors (5): 1 x 22 μF, 1 x 470 μF, and 3 x 100 μF (circuit operates at 5 VDC, so a cap voltage rating of twice or more is safe: 10 V+). A $10 capacitor kit should also have all values needed, check eBay.
• Transistors (7): 7 x model "S8050" and that's IF you want the BEST according to steve, but you can use the RadioShack favorite/standard, the 2N3904. You can buy 50 pieces of the S8050 transistor for about $2 bucks on eBay from Chinese sellers.
• Potentiometers: (3) 2 x 10,000 Ohms, 1 x 100 Ohms. a) The 10,000 Ohm pots should be centered to 5,000 Ohms on both terminals to start the circuit off. Alternatively, you can substitute these pots with four 5,000 Ohm resistors in series, 2 for each line, with the center point soldered to the transistor base. b) As for the 100 Ohm pot, you can either get it or fiddle around with 10 to 90 Ohm resistors from your pack to find the best output value for the Luma/Y. I'll try to determine the best value for this when I get a chance.
• Diode (1): One, any cheap low-watt model will do.
• PCB: One 5cm x 7cm board is good enough to build this circuit on. Have fun!

This image is a little outdated because of how much steve changed the design. I will update it eventually. Stuff like the S8050 transistors shown is still relevant. It's just the capacitor types that have changed.


Notes:

• If you can get a ceramic version of the 22 μF capacitor, that would be better as ceramics are non-polarized! The ambiguity here of voltage direction doesn't best lend itself for polarized aluminum caps. Ceramics start getting expensive for bigger caps such as the 100 μF and so forth, so just pay attention to the schematic for polarity when it comes to the aluminum caps that you'll have to use, same for that last 470 μF cap (negative end goes to jack/TV).
• S8050, NPN transistors can be bought cheap on eBay by this seller, yankee_electronic. A pack of 50 for ~$2 bucks, etc. Search his eBay store if he has them up for sale, and after purchasing, ask for S8050 so you get regular, full sized transistors and not surface mount, small type ones, etc.
• Pretty sure everything can be purchased at your local RadioShack if you're impatient, prefer retail options and go with the 2n3904. For caps, the 470μF are standard, but cost a $1.69+ each, so are the 220μF, and the 22μF ones might or might not be there though. They have a 500 piece $9.99 1/8 watt resistor kit or a $13 1/4 resistor kit (1/8w is fine!). PCB boards are $2.19 each, but for that much money, you can buy 10 pieces from a Chinese seller on eBay... There is a 15 pack of transistors, 5 of which are the 2n3904 needed for about $2.99+ or so... As for RCA jacks, they are a complete ripoff at RS... So, in the end, I recommend just getting used to learning how to shop on eBay for this stuff. You'll have to wait longer, but your money will go so much further. Example, for $4 bucks I bought 100 S8050 transistors, the good kind that are steve-approved... They came, I tested them on my SNES mod, they work fine! With the same amount of money at RadioShack, I get only 5 of the needed transistors and they're generic... Pathetic!

Cheap hobbyist PCBs are plentiful on eBay (bought 10 pieces for $2 bucks) such as this 5cm x 7cm board which is perfect for this mod:



These wall plate gold-plated RCA jacks are also perfect if cheaper than buying 3 jacks individually, though they usually come in standard yellow (composite), white, red colors, but nothing a little good blue & green nail polish can't solve to give you the proper coloring for component jacks as I did here:


EBay Search for "rca wall plate" with or without "component".

This circuit is still a WIP and subject to revisions. I have yet to build mine, though I was responsible for pestering steve to help me when I tried to use the R-Y/B-Y outputs off the HuC6260 chip, but we eventually found that repairing these signals outputted by the chip was not worth the trouble and that led steve to later design the Red/Blue/Y mixer you see above! There are plans by BlueBMW and steve to manufacture professional printed circuit boards of this, so you may be able to buy one from them in the future instead of building it yourself. But I think this will be an enjoyable mod to perform yourself (building the circuit), so that's why I'm not gonna wait.

Screenshots of the first circuit built for one of steve's customer can be found here:

https://www.tapatalk.com/groups/pcengine/rgb-mods-t174-s10.html
https://www.tapatalk.com/groups/pcengine/rgb-mods-t174.html


Jailbar Fix Guide - It is also recommended that you perform this simple mod to eliminate the "jailbar" problem that can occur in some cases.

pcengine-fx.com/forums/index.php?topic=13231.msg287992#msg287992



A little History here with the old design of the circuit. Steve said the customer was getting "shadowing" effects with this circuit. It tried to use the existing Luma/Y that the chip produces and mix it with RGB Red and Blue, but steve concluded there was a syncing issue with doing that causing the "shadowing" and what not, so he decided he would have to tap RGB and Sync to fully produce his own matching Luma, making the new/current design far more complicated. Anyhow, I leave a link to the old design for reference and just in case for others to fiddle with.

https://i237.photobucket.com/albums/ff216/Sephiroth1975/General/NECHuC6260YPbPrMod.png

[thesteve]

its a fun build, but i wouldnt want to do it from scratch twice

[turbokon]

I just asked thesteve for this:) My next project. Planning to component mod one of my tg16's.

[Drakon]

wtf, that's really easy.  Has thesteve made and tested this circuit yet?

[NightWolve]

wtf, that's really easy. Would this work with any rgb source?

Nah. It's only if the Luma/Y signal is already being outputted/prepared by the video chip and is ready for TV use as it is in this case (it's been mixed with sync and RGB). Otherwise, you'll need the standard more complex circuit that inputs all RGB signals and composite sync to convert to whatever, etc.

Has thesteve made and tested this circuit yet?

Yeah, he built/tested it for one customer. There were some hiccups, but it works now.

[thesteve]

[Keith Courage]

So this will do component without the use of an external converter box?

[Frank_fjs]

Maybe it's just the camera or TV but that SFII pic doesn't look right to me.

Seems to be saturated with too much green, there's something weird happening on the edge of the screen (a vertical green bar) and pixels aren't as defined as I would have expected for a component picture, everything looks washed out and blurry.

Not trying to be a stick in the mud or anything, I commend your ability to create such a circuit.

[Drakon]

Yeah this is an awesome circuit for sure.  My next question is, does the picture quality look better than that amazing s-video circuit?

[thesteve]

the S-Vid looks a bit better.
yes my green is a tad hot

[Drakon]

Interesting.  If you take the rgb from the console, amp it and convert it to component, then would that component video look better than the s-vid?  I must say the s-video from console is a force to reckon with it's the best looking built in s-video.

the S-Vid looks a bit better.
yes my green is a tad hot

[NightWolve]

the S-Vid looks a bit better.
yes my green is a tad hot

Mmm, that's a troubling thing to say... If that is true, no reason to go this far then... The s-video out of my SNES is terrible compared to the component mod I started on it. Dot crawl, wavy interference, etc. You get beautiful, rich colors, contrast, no dot crawl when you switch to component in that case... Anyhow, I will see what the deal is when I get going on my Turbo Duo. That wasn't the best picture you posted to showcase the results, but oh well. ;)

[thesteve]

you might get better with a converter.
likely equiv to S-Vid

the green could be adjusted by R9

[HercTNT]

I"m just always impressed when people dream this stuff up and make it work. call me easy but tech stuff like this is great.

[thesteve]

the S-Vid looks a bit better.
yes my green is a tad hot

Mmm, that's a troubling thing to say... If that is true, no reason to go this far then... The s-video out of my SNES is terrible compared to the component mod I started on it. Dot crawl, wavy interference, etc. You get beautiful, rich colors, contrast, no dot crawl when you switch to component in that case... Anyhow, I will see what the deal is when I get going on my Turbo Duo. That wasn't the best picture you posted to showcase the results, but oh well. ;)

sounds like you have horrid S-Vid on your SNES
S-Vid is a type of component and should perform close.
it does depend on how the TV implemented it.
if the TV mixes S-Vid to composite first, it will look like composite.
if the TV processes the luma and chroma separately it should be really sharp

[NightWolve]

The s-video was definitely much better than the standard composite output out of that SNES; less dot drawl, sharper picture, I'd say like a 15% improvement, but the component signal was far beyond better! Deep, rich colors, no interference or blur, high contrast/sharpness, dot crawl practically eliminated when scrolling occurs, etc. Anyway, you took that picture before any of the recent tweaks/improvements/adjustments in the design, so that is not a good reflection of the mod. We'll see how it goes in my case.

[thesteve]

S-Vid should never have dot crawl, as that is a composite issue caused by mixing luma and chroma

[NightWolve]

I wasn't aware the separating of luma and chroma eliminated such artifacts 100% ? I figured a reduction, not complete elimination. Is that right, s-video completely eliminates that problem ?? Anyway, if these artifacts I'm seeing are not dot crawl, then I don't know what to call them... While there was ~15% improvement in contrast/colors and reduction in dot crawl or whatever after switching from composite to s-video in the case of my SNES and this TV, going from s-video to component was a fantastic improvement by far! Big difference!

[PCEngineHell]

My older Apex crt tv's s-video quality ended up surpassing my other crt's svideo and component input both. Crt sets were really never cut and dry. Some companies took some serious short cuts on them, but as Steve said, you really should not be getting any noise in the s-video inputs picture unless they implemented a bunk method of handling it. S-video should be just a notch below component, with just barely a tad more color bleed.

[SignOfZeta]

While the theoretical differences between composite, s-video, and component are pretty cut and dry, the practical advantages vary widely depending on the chip actually producing the signal and the set displaying it.

The Genesis 1 for example produces a composite signal that is blurry as all hell. It gives composite a bad name. Doing the s-video mod on a Genesis 1 is an enormous improvement partially because s-vid is better, but equally because of the fact that the composite was so shit.

On a good late-90s/early 2000s CRT with fancy comb filter options and a system like the SNES which produces a rock solid signal, s-video is pretty damned good. With properly line-doubled RGB its hella sweet, but honestly even the composite is pretty great.

I have a CMVS with a NeoBitz and frankly the s-video and component are so similar I'm not sure I can't even tell the difference on my Sony XBR set.

I also have a JVC pro production monitor on which s-video is pretty underwhelming. Fancy filters and such are often left out of such monitors since there is no point in a monitor that scrubs the signal since its only going to mask defects that eventually make it to tape. Its assumed that your Y/C is coming from a camera or tape and is already pretty clean. Therefore on this set the component mod is usually going to make a significant upgrade over Y/C.

So yeah, it's all over the place.

[Drakon]

I agree I'm just impressed you built this.  This's no easy thing to make.

I"m just always impressed when people dream this stuff up and make it work. call me easy but tech stuff like this is great.

As for the s-video from a snes, it isn't the greatest out of the box as demonstrated here:

If you watch this video in 720p, the right screen is the s-video from a non modified model 1 snes.  The left screen is the s-video from my snes mini where I bypassed the built in video encoder and installed a sony cxa2075 encoder circuit.  The revision 1 snes ppu has blurry rgb right from the chip, the model 2 ppu has sharp rgb but the built in video encoder isn't as sharp as the cxa2075.

[KnightWarrior]

You made it 16x9

Take a pic displaying 4x3

[Burnt Lasagna]

Good luck with this mod NightWolve!
I've always been interested in doing some hardware mods myself, though I haven't really done anything beyond the basics...
Still enjoy reading mod WIP logs, always makes me threaten myself to explore this field more

[ConHuevos]

Any other pics of this?  I'll definitely do this mod but not if it turns out like thesteve's screenshot haha, way too much green.

[NightWolve]

What do you know, my final order from China happened to arrive today, a 200 pack capacitor kit - it had the 22uFs and 470uFs needed! I now have all the parts necessary and even recorded parts of the youtube video for determining placement of RCA jacks and drilling the holes, etc.

What the hell, lemme throw images up from the video (animated 5 seconds apart, lighting sucks and so does the camera, but oh well).



How's it looking? =) That's my BluRay player underneath so that I could put the jacks in the most standard order and instead of composite where the yellow jack is, I got a s-video mount in place! In order to make full use of the limited real estate in that area and achieve 2 rows of jacks, I had to modify the PCB of the power supply input behind them. There's a stupid little "choke" I guess it's called, coiled wires going around a piece of metal in a plastic mount, and I had to desolder it off the PCB and solder 4 copper wires in place so that it could be moved away. Also, there's a plastic stand for the output power wires that go to the motherboard, and since it's 1/4" high and isn't removable anyway, I soldered it off and instead soldered the wires directly onto that PCB. That pretty much gave me full clearance to use both rows without any trouble!

Any other pics of this?  I'll definitely do this mod but not if it turns out like thesteve's screenshot haha, way too much green.

Nope, not yet, sorry. I have to talk with steve some more about the state of things. From our last conversation, I gathered that he concluded that the Luma signal off the chip isn't quite as it should be and as a result, he's decided to build a full RGB->YPbPr circuit that would need to accept Red/Blue/Green/Sync signals and mix them all... If that's what it takes to get the mod to work on 8bit4life's particular TV, then the current circuit is about to get more complicated. I'll have to catch him on the chatroom and talk some more tech with him about this...

[ConHuevos]

There's a tg16 tech chatroom on irc?  What server/channel?

[NightWolve]

EDIT: We have our own embedded chat now.

[turbokon]

Looks great bro!!  Definitely this is something I want to do on one of my systems, question is which one should I do this on?

[turbokon]

Seems like yesterday you were replacing caps for the first time, now you're building component PCB. Great work!!!

[NightWolve]

Seems like yesterday you were replacing caps for the first time, now you're building component PCB. Great work!!!

Thanks man! Just FYI though, "stevie wonder" (AKA thesteve) of course designed it, I'm essentially helping to get the word out and I made a nicer image for it all! ;) I guess my role was helping to pester him into doing this, though. I was trying to use the Red-Y and Blue-Y off the chip many months ago, and he was helping me to try to fix the signals with circuits he was coming up with on the fly, but we didn't succeed. In later thinking about it, he decided it'd be better to take the RGB Red and Blue signals and mix them with the working Luma and give up on fixing the existing signals that the chip was producing. So that led to the current circuit that you see. I DID design and build a component circuit for my SNES though with what I learned from steve! I wanna make a separate thread about that later though!

But yeah, fixing my ole Express via full capacitor replacement was good fun! When I was in my teens, I actually would fix mechanical failures for VCRs for this local Resale shop. They'd buy the VCR broken for a few bucks, and gimme $10-20 if I could fix it in my leisure. Rubber band stuff, cleaning, worn out springs, even changing the heads with a new cylinder if I could get the part ordered from the manufacturer (my suppliers were Dalbani and MCM electronics), that sort of thing, etc. But it always bothered me that I didn't understand electrical components and how to handle their failures, etc. Normally, like I said in the video, when I was a kid, always wanting to open up electronics to see what was inside would usually lead to the end of the product functioning... ;) Ah well, it was all in the name of science! These were necessary sacrifices!!! Heh-heh!

I guess from what SignofZeta said, I'm kind of wrong about something else I said in my video, about the 10-20 year cap failure rate and that NEC just got a really bad batch of electrolytic capacitors and that's why their hardware has had such a high cap failure rate. Wikipedia suggested that if you don't power on a device that has such capacitors and leave them sitting there for 5-10 years, that could accelerate their failure rate, hence the use 'em or lose 'em bit... Well, I dunno... Anyhow, I guess the evidence seems to point more to that NEC, one of many producers of electronic devices, was the victim of a bad patch of electrolytic caps as were others of that era.

Anyhow, on the status of the component circuit, I'm currently waiting for steve's next revision... His latest findings are that the Luma signal comes out late by a few milliseconds in the current circuit design and that causes a color shadow apparently. So, expect an upcoming revision to the current circuit in the first post when I hear from him. He said another 3 resistors and an amp will be needed...

[turbokon]

I'm sure thesteve will figure it out soon enough, that's one smart dude there. I'll wait until he finalize the design until I start on it.

[thesteve]

RGBS from the chip (full encoder)

Lastest:

[thesteve]

new circuit

Lastest:

[thesteve]

slight update (id=79)

Lastest:

[oreo76]

i posted on another thread already..but i modded a briefcase with component:

[thesteve]

did you mean RGB?

[ConHuevos]

That looks great,  but I'd like to see a "zoomed out" picture as well, kinda hard to tell with just a close up.  It seems to look great though!

[NightWolve]

If I didn't know any better, I'd say that's like the best screenshot steve's ever taken, minus him not resizing it proper for easy viewing though. ;)

(Same image, resized down to 2 sizes and pixel rotated a bit to straighten it out.)



Well, that IS looking good! I can say that now!! There's some blur, likely from slight camera movement that's very apparent with Dhalsim, but pretty good other than that.

If somebody with a RGB modded system and TV could load the game and take the same screenshot for comparison, I'd appreciate it. steve?

Anyway, good work man! I'll get the cap value and signal input details from ya whenever, I'm kinda busy right now, but when I get a chance I wanna update the OP with the new circuit. Or, looks like you added them after all, I see 470uF on C3. And I figure RGB Green is inputted at R1, and Composite Sync at R2 (or vice versa) and RGB Red and Blue at the bottom inputs as usual. Looks like only 3 caps needed now, but more resistors, a diode, and another transistor. Well, not as simple as before, but not terribly complex either AND still cheap!

EDIT: Here's a comparison versus the MagicEngine emulator. Either that TV's old and it's a brightness issue or the mod, etc. whatever the case, the blue curtain underneath the trunk of that elephant is failing to appear. Other problems aside from darkness like color vibrancy, even though this is not a fair comparison against an emulator, it does reveal some obvious problems that can be improved I should think. You should pause it and also have the composite signal hooked up, steve, and see how things look compared to its output, etc.

ME	TV

[NightWolve]

did you mean RGB?

Yeah, he said RGB mod in his youtube video. Since raw RGB is also referred to as a component type signal, he thought that's what this was about I guess.

i posted on anotehr thread already..but i moded a briefcase with component:

This thread is about getting a working YPbPr Component type signal out of NEC hardware; the circuits you've seen steve posting are not your usual raw RGB amps and what not. They're mixer circuits essentially, mixing the raw RGB and Sync to form Luma and also mixing the inverse of Luma with RGB Red and Blue to achieve the desired Blue-Y (Pb) and Red-Y (Pr) signal outputs, etc.

Reference: http://en.wikipedia.org/wiki/YPbPr



It's a type of "Luma-based analog component," a general description which also covers S-Video and it was the last analog signal standard here in the U.S.A. before the jump to digital HDMI. You guys had the SCART standard in Europe, we got this, not as good as raw RGB, but much better than Composite and S-Video, etc. The color choice of green for Luma/Y when it comes to RCA cables and jacks is somewhat misleading (one might initially think it's raw RGB Green), as it's really a mix of RGB and composite sync, but since green is mostly derived from it (along with the Red-Y and Blue-Y), I suspect that's what factored into choosing that color.

[thesteve]

you asked for it

[Duo_R]

Any other games? SF has always looked weird to me on component on old systems. It ends up looking much granier than some of the other games.

[thesteve]

sure no prob

[PCEngineHell]

You need a better camera lol.

[thesteve]

have one somewhere

[thesteve]

change R14 to 500ohms
add cap

Lastest:

[Game-Tech.US]

change R14 to 500ohms
add cap

I see two Q1's...
Are C1 and C2 22 'uF' or ?

[thesteve]

so i got my Qs numbered wrong
yes 22uf c1, c2

[NightWolve]

YPbPr (Plasma TV)	Composite (CRT TV)

EDIT: Whoops. Little bit of mis-communication there between steve and myself. I had suggested a RGB v. YPbPr compare, but these shots were YPbPr v. Composite... Results are self-evident. YPbPr is far superior of course!

[PCEngineHell]

I gather Steves set is suffering from some major lag there due to the difference in character animation taking place between the two tv sets. Lag looks to be significant too. But anyway, these shots with the phone camera are way too shity to make any good judgement calls on quality here. I'd rather stay reserved until work is finalized on the mod and someone with a decent camera can take some shots.

[thesteve]

i wouldnt call that lag, as the plasma simply is showing 2 frames at once (displaying as 480I)