YPbPr ouput mod for SNES consoles

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vingadorjr2
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Re: YPbPr ouput mod for SNES consoles

Post by vingadorjr2 » Sat Jul 20, 2013 9:05 pm

NightWolve wrote:
vingadorjr2 wrote:My chip says S-RGB. Its the 1Chip SNES model. Ive soldered the Luma from the S-Video pin at the Multi-AV out AND, just for test, from the Luma out on the chip too. The same result, "pink" screen. If i amplify the red and/or blue, doesnt it going to becamo even more red and/or blue? I dont think it can solve the problem. The problem seems to be the lack of green from the Y out on the RGB chip.
Sorry, you can stop right there, you have the wrong model. End of the story. You can only tap S-Video from these models... :( You have no Red-Y and Blue-Y outputs from that S-RGB video chip, so it's not going to work no matter what you try... You need an external encoder chip (like JROK) which would tap the Sync, and RGB lines and produce a genuine YPbPr signal if you really wanted it... Only other option is to buy a another used SNES model and check that it's made on 1990 to 1993 and what not.

I understand NightWolf. It seens you are right. I just dont comprehend how those people got Component YPbPr out from their S-RGB chips... maybe they are using these external chip to transform the signals like you said. It seems that it is the case...

Back to the S-Video mod then... im having problem with this mod too. Im hooking up the wires from pins 7 and 8 (Luma and Chroma) from the multi av out pinout to the svideo jack, without any cap or trans. Im sure that the wires are connected in the right way on the svideo jack, by following that famous svideo pinout picture. Then, im taking the 2 grounds from the iron faceplate, the same place where i got the ground for the failed component. The grounds are alright too, but im not getting any image. Ive already done this svideo mod several times on the Genesis (Mega Drive) with sucess... but thares something wrong with this snes mod.

Any clue or tip?

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NightWolve
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Re: YPbPr ouput mod for SNES consoles

Post by NightWolve » Sat Jul 20, 2013 9:27 pm

vingadorjr2 wrote:I just dont comprehend how those people got Component YPbPr out from their S-RGB chips... maybe they are using these external chip to transform the signals like you said. It seems that it is the case...
Yeah, it's an external board like say the JROK, a circuit that takes RGB + Sync in and outputs YPbPr. I don't think you're ready for that. ;)
Back to the S-Video mod then... im having problem with this mod too. Im hooking up the wires from pins 7 and 8 (Luma and Chroma) from the multi av out pinout to the svideo jack, without any cap or trans. Any clue or tip?
Yeah, already pasted. These guys show you how to do it right:
http://console5.com/wiki/SNES#S-Video_O ... SNN-CPU.29

You don't need any transistors for amplification - the signals are almost ready for use (too strong, in fact, right off the chip). You just need capacitors to filter out the DC offset and a little resistance.
Im hooking up the wires from pins 7 and 8 (Luma and Chroma) from the multi av out pinout to the svideo jack, ... The grounds are alright too, but im not getting any image.
Yeah, that's because there's NOTHING there at pins 7 and 8 when you begin (that's the problem, Nintendo forgot or whatever)... You will solder the output to there after tapping the S-RGB video chip!

1st http://console5.com/wiki/File:SNES-V2-S ... ctions.jpg
to
2nd http://console5.com/wiki/File:SNES-V2-S ... ctions.jpg

Pin 17 and pin 12 on the S-RGB video chip must be first tapped - see 1st image above. You go from pin 17 on the video chip, to pin 7 on the Multi-AV out (2nd image), and pin 12 to pin 8, etc. Just like it tells you in that first link and is showed in the 2nd pair of images! So basically, after this mod, the Multi-AV out will work again WITH the original, standard SNES S-Video cable!
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vingadorjr2
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Re: YPbPr ouput mod for SNES consoles

Post by vingadorjr2 » Sat Jul 20, 2013 10:50 pm

NightWolve wrote:
vingadorjr2 wrote:I just dont comprehend how those people got Component YPbPr out from their S-RGB chips... maybe they are using these external chip to transform the signals like you said. It seems that it is the case...
Yeah, it's an external board like say the JROK, a circuit that takes RGB + Sync in and outputs YPbPr. I don't think you're ready for that. ;)
Back to the S-Video mod then... im having problem with this mod too. Im hooking up the wires from pins 7 and 8 (Luma and Chroma) from the multi av out pinout to the svideo jack, without any cap or trans. Any clue or tip?
Yeah, already pasted. These guys show you how to do it right:
http://console5.com/wiki/SNES#S-Video_O ... SNN-CPU.29

You don't need any transistors for amplification - the signals are almost ready for use (too strong, in fact, right off the chip). You just need capacitors to filter out the DC offset and a little resistance.
Im hooking up the wires from pins 7 and 8 (Luma and Chroma) from the multi av out pinout to the svideo jack, ... The grounds are alright too, but im not getting any image.
Yeah, that's because there's NOTHING there at pins 7 and 8 when you begin (that's the problem, Nintendo forgot or whatever)... You will solder the output to there after tapping the S-RGB video chip!

1st http://console5.com/wiki/File:SNES-V2-S ... ctions.jpg
to
2nd http://console5.com/wiki/File:SNES-V2-S ... ctions.jpg

Pin 17 and pin 12 on the S-RGB video chip must be first tapped - see 1st image above. You go from pin 17 on the video chip, to pin 7 on the Multi-AV out (2nd image), and pin 12 to pin 8, etc. Just like it tells you in that first link and is showed in the 2nd pair of images! So basically, after this mod, the Multi-AV out will work again WITH the original, standard SNES S-Video cable!

Thanks again NightWolf but my model is the FAT, so i dont need to tap between the chip and the av out pinouts. This trick is only for the Jr or Mini. Ive found where i was doing wrong... just found the culprit (http://moviespics.wcgame.ru/data/2011-0 ... pinout.jpg). I dont know HOW a human being can do this kind of mistake to loose time in making a so pretty schematic with this wrong pinout! Now... just imagine the number of people like me that fall for his mistake and loose days trying to figure out whats wrong! LOL

Anyway... ive taped the wires from pins 7 and 8 from the AV Multi Out directly to the jacks and it does the trick, without caps or transistors. I must admite that im a little disapointed with the result. Ive spend some time doing comparisons between the composit and svideo and dont find any relevant diference. Its 98% the same quality between the two (and same color level). On the Genesis the diference is absurdly high! There, the s-video is something like 40% better then composite. Something like that... but not on this 1Chip model. I dont know if this is good or bad... but after this much of a work, i got a little disapointed. I will try some caps and transistors combination another day to see if i can make it better.

Anyway... i will follow your advide and will try to sell this svideo moded snes and buy a S-ENC one to try the component mod. Very very very thanks for your time and let me know if theres something i can help with.

Ps. Are you the same NightWolf from the Ys translations?

sazyario
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Re: YPbPr ouput mod for SNES consoles

Post by sazyario » Fri Jul 26, 2013 2:20 pm

So I finally picked up a decent CRT to test my SNES on.
A 2004 Toshiba 27". I really wanted a 24" Sony Trinitron WEGA. But beggers can't be choosers.

Anyways my red is too intense. I'm not sure if I should add a higher resistor to the final output from the red amplifier or to remove it. I'm kinda sick of tinkering.

I know for a fact that the blue needs an amp. The ocean in Super Mario World seems... Ugly? Can't describe it better. Greens are amazing.


Real quick question though!
I tapped the Y from Pin7 on the underside of the MoBo. But if I try to use composite I only get a green and yellow picture. Do I need to use a diode facing the Y jack on my mod to preserve composite?

Thanks!

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Re: YPbPr ouput mod for SNES consoles

Post by lidnariq » Fri Jul 26, 2013 2:42 pm

If I remember correctly, the component pins on the SNES RGB->composite converter are both 1- not really rated to source current and 2- brought back into the same IC to create composite and s-video chroma. Hence the problems you're seeing, and why everyone else has been throwing opamps at the problem.

If that's correct, a diode won't fix it.

sazyario
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Re: YPbPr ouput mod for SNES consoles

Post by sazyario » Fri Jul 26, 2013 2:58 pm

lidnariq wrote:If I remember correctly, the component pins on the SNES RGB->composite converter are both 1- not really rated to source current and 2- brought back into the same IC to create composite and s-video chroma. Hence the problems you're seeing, and why everyone else has been throwing opamps at the problem.

If that's correct, a diode won't fix it.
I'm taking it from pin7 of the multi av out port.
Not from a chip. I should've clarified.

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Re: YPbPr ouput mod for SNES consoles

Post by lidnariq » Fri Jul 26, 2013 3:10 pm

Oh, looking at the schematic they actually connect Svideo luma out back into the S-ENC to generate composite, so it is possible to break things...

That said, I know I've plugged in both S-video and composite to a TV at the same time and not had it screw up.

Also, color errors (instead of brightness errors) imply that's not where things are going wrong.

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NightWolve
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Re: YPbPr ouput mod for SNES consoles

Post by NightWolve » Fri Jul 26, 2013 4:52 pm

sazyario wrote:So I finally picked up a decent CRT to test my SNES on.
Real quick question though!
I tapped the Y from Pin7 on the underside of the MoBo. But if I try to use composite I only get a green and yellow picture. Do I need to use a diode facing the Y jack on my mod to preserve composite?
Hmmm. The only limitation of sharing Luma/Y for your YPbPr Component output with the native S-Video is that both can't be plugged in at the same time, otherwise Luma/Y will get slightly attenuated for both outputs (YPbPr and S-Video) resulting in a darker picture for both. That's all... Not a problem, don't plug in both cables at the same time... I'll never use S-Video again given how great the picture is on my CRT 32" TV. Shimmering elimination is pretty significant, if not almost gone. Anyhow, your use of the ready-to-go Luma/Y here wasn't the problem with Composite.

You'll need to use simple transistor amps on both the Red-Y and Blue-Y signals if you wanna be able to have Composite and YPbPr cables plugged in at the same, that's all. Both of those signals (Red-Y/Blue-Y) are sent back into the chip as mentioned to produce Chroma for the S-Video output and to mix for the Composite signal. So if you're trying to cheat, like I did for the Blue-Y signal and get away with just using a cap for DC filtering and a resistor, this is one limitation as a result (you'll cause attenuation back in that line and affect Chroma strength!). Either plug Composite or YPbPr Component one at a time, or use a transistor amp. The transistor copies/amps the signals and doesn't cause attenuation behind it, so that's the only solution that I know of. I don't really consider this a problem, since once you get the output resistance right, and you get it all tweaked, you should just be plugging in one form of connection anyway, the best and forget about Composite unless you have to go back to a TV that rejects a 240p signal via the Luma/Y jack, etc.

I would break with others here in recommending op-amps because the great native Luma/Y amp of these SNES units is a simple transistor amp (if you take a look at the circuit) and it's not that far off from my first circuit design. I think the best amp would be transistor-based and should be modeled after how it's done internally with Luma/Y, etc. My 2 cents. Everyone will be able to build it and not need special, rare ICs, etc. and Radioshack 2N3904 NPN transistors work exactly the same as what the SNES engineers used, the 2SC2412 model. I tested it against 2n3904 and my S8050 and they amp'ed exactly the same. I'll post the SNES amps for Luma, Chroma and Composite when I get a chance via some very nice images (already started it, but got distracted) and hopefully someone with real engineering background can help design the "best" circuit for the Red-Y/Blue-Y signals off the same chip in getting to see the clear style that SNES engineers chose. Someone that's, you know, actually willing to crack open their SNES too!
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sazyario
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Re: YPbPr ouput mod for SNES consoles

Post by sazyario » Sat Jul 27, 2013 7:19 am

Ok. It's good that you say an amp on both Red and Blue should fix things.
Just one lingering question. The Reds, Pibks and Oranges are very intense.
The best example is that the Red Koopa orange face and red shell almost blend together.
Can I simply use a higher ohm resistor to try and bring that level down?

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NightWolve
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Official SNES-designed circuits for Luma, Chroma & Composite

Post by NightWolve » Sat Jul 27, 2013 7:19 pm

sazyario wrote:Can I simply use a higher ohm resistor to try and bring that level down?
Yeah, or if you have a 0-100 Ohm potentiometer, that would be good to attenuate the output resistance down after amplification to where the colors appear best to you. You could start at 15 Ohms if you got a pack of solid resistors. With the imbalance of the chips as far as signal strength goes of the Red-Y/Blue-Y signals, and different motherboards 90-93, I think the only universal recommendation will be just a 0-100 Ohm potentiometer on both lines.

P.S. The internal SNES Luma/Y amplifier circuit has 39 Ohms in series as the output resistor. That was tweaked/chosen in consideration for a custom 8 ft. S-Video cable (that's right, the standard SNES S-Video cable is a little over 8 ft.!), so I think when one solders a wire on the 4th pin (from the left at the Multi-AV out) to a good female RCA jack, and then say uses 4 ft. copper RCA cables, resistance is reduced, I'd say max 2-5 Ohms. I'm thinking this is why some people here wanted to add a resistor to Luma/Y as well after this mod feeling that the picture was a little too bright. The conversion to a RCA jack is better in delivering Luma/Y to the TV than a 8 ft. long custom S-Video cable that typically will be using aluminum wires instead of copper like a RCA cable would. Just a theory.

Addendum: You know what, it's too early, I really haven't finished this image, but I'll share it anyway. Since I didn't get to labeling it, putting up needed details in it, I'll explain that textually here.

1st Circuit: This is the official Luma/Y amplifier circuit designed by SNES engineers on a 1990 motherboard with the S-ENC video chip for the S-Video output. Notice that they use two 39 Ohm resistors for a total of 78 Ohms as the total pull down resistance after amplification (the transistor's emitter output). Compare to my use of a solid 80 Ohm resistor for my simple Red-Y/Blue-Y transistor-based amplifier circuit posted earlier and kyuusaku's statement (who knows everything and has to see 75 Ohms everywhere or it's wrong, yet it's used nowhere below!) that my use of 80 Ohms "wastes loads of current!" and is part of why my circuit "makes no sense!" Also, the Composite amplifier at the bottom uses 100 Ohms as the pull down resistor.

(Point ?? There's nothing magical about 75 Ohms where it somehow always has to be used in series in the output stage or as the "proper" pull down resistance or whatever else... The only place where that's true is on the input module of the signal receiving device, the TV in this case; when we say that the input impedance of your TV's Composite video jack is 75 ohms, what that translates to is that there is a solid 75 Ohm resistor connected on the female jack from + to ground, right there! So, as soon as you connect a cable, whatever cable, the TV's input module immediately grounds it with a 75 Ohm resistor! That's where the standard of 75 Ohms really comes into play!! To test this, just connect a yellow RCA cable to your TV's Composite jack, then take a DMM set to read resistance, and touch the male tip and ground of your cable on the other side, you will see about 75-77 Ohms of resistance.)

All Circuits: Image updated, explanations added.

(FYI, "PCB123" was the software used to create the schematics. Very nice, clear, I think!)
Image

Anyway, as you can see, the first Luma/Y circuit has a 39 Ohm output resistor in series and that was chosen with that 8 ft. S-Video cable in mind, I would suspect. If that cable was shorter, with good copper wire and in RCA form instead for YPbPr Component output, I'd guess that resistor would have to go up a few Ohms, not much, but by a few (2-5 Ohms max)!

So, my thinking is this: I want a transistor-based amplifier circuit for Red-Y and Blue-Y designed with the decisions that SNES engineers made given the above Luma, Chroma, and Composite circuits. I think that's what would be the best, not the use of these op-amp circuits some have come up with. I wanna be able to build it from off-shelf parts, even be able to walk into a Radioshack and buy all needed parts! The Luma/Y that the above circuit produces is pretty rock-solid, so I don't see the advantage in using it while then turning to different components to amplify Red-Y/Blue-Y, these op-amps. Bottomline, I think the perfect Red-Y/Blue-Y amplifier circuit should look similar to what is seen above, etc.

Some Notes: The resistance values are EXACT as measured on a 1990 SNES motherboard. I also used my capacitance measuring feature and the 200 uF capacitors that are connected in series and used as a pull down, all were measured to be exactly 200 uF. So this is better than the SNES schematics which show generic values. Example: that 3000 and 5000 Ohm pull down resistor you see that I accurately measured ?? Well, the generic schematics call for a 10,000 Ohm resistor, but that's NOT what actually was used, at least, on my 1990 SNES motherboard.

Also: The NPN 2SC2412 transistor showed above that SNES engineers chose has that same exact amp'ing power as the Radioshack 2N3904, or my preferred replacement of it, the S8050! I actually desoldered an original 2SC2412 off of a spare SNES motherboard and used to to amplify my Red-Y line, then I used the 2N3904 and the S8050, I took screenshots of the same paused game with the EXACT same results! The point: there is nothing special about the SNES chosen 2SC2412 transistor!! So FYI, a good circuit for Red-Y/Blue-Y amplification is possible with standard parts here and you could get it as good as they did when it comes to Luma/Y!!

Anyhow, I will finish that schematic tech image eventually, so it should get better in time!
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NightWolve
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Re: YPbPr ouput mod for SNES consoles

Post by NightWolve » Sun Jul 28, 2013 11:22 pm

Alright, I neglected to respond to this earlier, but felt like doing so now. Sorry to get testy, but it's warranted.
kyuusaku wrote:
Pasky wrote:Hmmm maybe its possible the luma ouput is different per snes revision.
Or maybe people are creating broken "amps" due to minimal understanding of video signals, termination or transistor amplifier topologies.
Pasky's desire to slightly attenuate the native S-Video-prepared, ready-to-go Luma/Y for use with a YPbPr output mod had NOTHING to do with my Red-Y/Blue-Y amplifier circuit or ANYBODY else's that you wanna throw stones at! NOTHING! If you or ANYBODY else produced the perfect Red-Y/Blue-Y amplifier circuit, he would still be complaining that the picture seems a little bright and I believe I understand why now but that's besides the point.
kyuusaku wrote:You're missing the point; of course the encoder's output is "compliant" with a DC offset. Luma is already prepped for series source termination so it's irrelevant.
MikeMoffitt didn't miss any point. You had none, and simply wanted to reiterate that nobody here has done a good enough job of producing a Red-Y/Blue-Y amplifier circuit to your satisfaction!
kyuusaku wrote:Wiring component's Y in parallel with S-video's Y does mean however that you can't leave S-video and component connected at the same time because there will be dual-loads. A simple remedy with a single resistor...
Funny thing, you could've actually been helpful here with this alleged "simple remedy" using a single resistor, but you didn't bother to actually tell us how!
kyuusaku wrote:What's really wrong is how Pb and Pr are handled, when you connect them directly a compliant signal is not what's delivered to your TV over the transmission line.
Yeah, no shit! That's what this thread is all about or should be, to come up with the best Red-Y/Blue-Y amplifier circuit. Did we really need you to reiterate that ?? How about instead you FINALLY just crack open your own SNES and dazzle us with what you could come up with ?? I can't be the only that thinks it's time for you to put up or shut up! Nobody, to my knowledge, has yet to claim that they came up with the perfect amp... People are giving it a shot. I'm sorry that they're not trained engineers for you, but tough noogies!
kyuusaku wrote:As for the Pb/Pr amp above, here's why it doesn't make any sense.
REALLY ?? No sense at all, huh ?? Just a weird buffer that serves no purpose here ?? Well, let's see about that and how much sense you actually made...
kyuusaku wrote:1) The video chip doesn't need protecting in a common-collector amplifier. The resistor actually hinders the feedback.
With his response here, he demonstrated no intellectual curiosity whatsoever! Instead of asking what this "protection" was all about, what my thinking was there (since I had arrived in the thread), he simply threw a "Hey, look at me, I say your circuit makes no sense!" type response without any kind of inquiry. I saw ego and arrogance there, didn't call him on it earlier, but am doing so now!

So, since you didn't bother to ask, how about I let you and anybody else know the thinking behind it ? Gee, what could it be ?? Well, it's not actually something that I came up with you'll be happy to know, I, not being someone with an electrical engineering background that is. Somebody WITH a background in EE actually DID, though! That would be thesteve, right here, who came up with a YPbPr circuit for NEC systems. See, there's a particular way in which a transistor breaks down. It can short, and if the collector to base junction shorts, then that would wind up applying a genuine +5 DC voltage back to what's connected to the base which is...either a Red-Y or Blue-Y pin!!! I'd rather a diode facing outward to fully block that or a 1K resistor be there should something like that ever happen!

So, I'm supposed to take your word that if that happened, the S-ENC video chip could likely handle a genuine +5 VDC being applied back to it ?? It doesn't "need" protecting ? It's about safety, and yes, perhaps overly paranoid as far as the odds of that Radioshack 2N3904 transistor of yours breaking down that way, but like you originally said on the 1st page of this thread, you care when mods involve the alteration of remaining video game stock. So, it's hilarious that you would list an attempt to protect the S-ENC chip on a system no longer manufactured as one of 4 reasons why my circuit "doesn't make any sense..."

You also complain that the 1K resistor would "hinder feedback," but ROHM engineers used 470 Ohms for the Luma, Chroma, Composite circuits where I used 1K for my simple Red-Y/Blue-Y circuit. Your shit doesn't seem to hold up very well. I tried 470 Ohms, I tried 1K, I got the same shit color-wise, only a very slight attenuation with 1K and since I STILL need output attenuation before going to the jack on to the TV, why the hell not have a bigger resistor (twice as big in this case) in place there so hardly any current could move back to the video chip if a transistor short occurred ?? If I lose a transistor, I lose the colors next time I turn on my SNES, I fetch another 2n3904, no big deal, but what I WON'T lose is my S-ENC chip!!! Yeah, doesn't make ANY sense at all, does it, eh chief ??
kyuusaku wrote:2) 80 ohms is unnecessarily low so it leads to lots of current waste. 80 ohms also isn't a preferred value. If it's dropped to 75 ohms then it also serves as a parallel source termination.
This is where YOU actually make NO sense! SNES engineers chose 78 Ohms as the pull down resistance after the amplified transistor output when it comes to their Luma circuit (though technically ROHM made that decision, you see it in their datasheet for the video chip).

So, for my solid 80 Ohm resistor versus the 78 Ohm total in the native SNES Luma amplifier, my circuit "stopped making sense" partly cause of that ?? REAALLY ?? For 2 f--king Ohms ??

So, "lots of current waste" with that 78 Ohms by SNES/ROHM engineers then, right ?? How about all the circuits that are even lower with 75 Ohms ?? I've seen plenty of that after a transistor! So everybody (and their professional circuit designs that I've seen) has been getting it wrong according to you, huh ??

Just how much voltage do you think there is on the emitter output of a transistor being powered by the +5 VDC on its collector end ?? My DMM read 2-3 V before the use of a pull down resistor and part of that is the DC offset of the video signal, not even genuine! How is one going to see "lots of current waste" with a 7X Ohm pull down resistor ?? Pfffft. You got a 470 Ohm resistor on their designs, so hardly NOTHING "current" wise would ever move through the base, only what comes out of the transistor's emitter in relation to it being powered would matter, and I think that's about 1 V. Whatever, take it up with ROHM/SNES engineers and a whole host of others, not me!!!
kyuusaku wrote:3) 470 uF is a good value for composite video which has low frequency components for sync, Pb and Pr don't have that, so it's unnecessarily high.
Well, this is debatable and I actually did switch back to 220 uF in my newer circuit which was RIGHT IN YOUR FACE, but you STILL went back to criticize the choice of 470 uF in the old one... That was curious! Nonetheless, why did I choose 470 uF originally ?? There's an answer for that, not that you cared at the time, because obviously you know better than SNES engineers and you ALSO know better than RCA engineers! Voila:

Image

I took this photo just for you! See, I figure that you think that I pulled that 470 uF cap choice out of my rear end, so I thought that I'd actually show that that wasn't the case... Well, hard to believe, huh ? That is an Audio/Video Output module from a basic RCA DVD player! And guess what ?? You see those three 470 uF capacitors right there in your face ?? All 3 of them, their negative terminals, go right straight to the RCA outputs for Luma/Y, Red-Y, and Blue-Y, etc. That's right, that's what the RCA engineers did for this particular model! There is no 75 Ohm resistor in between, in series! That's right, as I said, the negative lead of those 3 capacitors that you see there, go straight to the RCA output jacks. Indeed, I used my DMM and did a continuity test. Only about 2-3 Ohms of resistance results from the trace path in between the RCA jacks and the negative lead of the 470 uF capacitors.

So, there ya go, mystery solved! That's why I chose 470 uF originally! Does that make sense now for ya ? I saw that RCA engineers did it for this DVD player and thought that it was a standard design choice for YPbPr output. Sue me! I then also asked my engineer friend, thesteve, and he didn't have a problem with it either...

Now, why did I go back to 220 uF anyway ? Cause it's a cheaper capacitor, SNES engineers stuck with it, I looked at another DVD output module which used 220 uF as well, so if it's cheaper, smaller and still good enough to do the job of DC offset filtering, I guess, why not ?? So that's the story of how I went from 470 uF back to 220 uF!

Anyhow, to list 1 of 4 reasons that my old circuit "doesn't make any sense" because of the use of 470 uF capacitors for Red-Y and Blue-Y when RCA engineers did it for a PROFESSIONAL DVD player shows how much sense YOU make! Take your problem up with RCA engineers since you know better than them!!
kyuusaku wrote:4) 15 ohms R at the output serves no purpose but to marginally attenuate an already "compliant" 80 IRE peak-to-peak signal. A proper series 75 ohm termination would attenuate the level to 40 IRE which would really break things.
THIS made no sense whatsoever! You only had 3 genuine points to make, but in order to add a 4th one against my basic transistor amplifier circuit for JUST Red-Y and Blue-Y signals (I advocated against attenuating the native Luma from the VERY beginning and you NEVER ONCE saw ANY of my schematics indicate otherwise!), you threw in Pasky's desire to add about 15 Ohms of resistance to the native Luma output, yet his desire to do so, once again, has NOTHING to do with a competent, Red-Y/Blue-Y amplifier circuit!

Even if there was a perfect Red-Y/Blue-Y amplifier circuit, if the Luma is still coming in a little hot as he appears to believe, he'd STILL be complaining and wanting to add a few Ohms of resistance REGARDLESS of how good OR bad the Red-Y/Blue-Y amplifier circuit design is! Also, your apparent desire to see 75 Ohms everywhere (series-wise, before the output) doesn't hold up when looking at the official Luma, Chroma & Composite amplifier circuits in my previous post.

Finally, Pasky NEVER even used my amplifier circuit to begin with, so even if you were trying to blame his complaints of Luma on it, it STILL had nothing to do with it! He used Ziggy's earlier one! You simply don't need Red-Y/Blue-Y connected to know that you have a problem with Luma! He can plug in Luma by itself and feel that it's too bright, coming in a little too hot, etc.! Adding a perfect Red-Y/Blue-Y would only make the picture a little brighter if you ask me, I can't see how it'd make it darker, so his complaint wouldn't change with the perfect circuit if one is trying to make use of the native Luma!
My Ys Fan Translation Projects.
http://www.ysutopia.net/

Ste
Posts: 4
Joined: Mon Feb 04, 2013 1:54 am
Location: Chicago, IL

Re: YPbPr ouput mod for SNES consoles

Post by Ste » Tue Jul 30, 2013 11:34 pm

Hey, NightWolve. Long time, no speak. I played Celceta at E3 this year. It was pretty sweet. I might have to buy a Vita for that one. Anyway, if you're still hanging around Chicago we should meet up and chat about console video mods.

I don't want to hijack anything here, but once in a while I do Google searches on "SNES component cable". Since I support the Video Game History museum, one can see how I cringe everytime a system is modded for no reason. I decided to actually respond this time since I do have an account here. I know this is a forum of mostly technical people, but would people be interested in mod-less SNES component cables? In addition, I would guarantee that this solution would have higher picture quality than any mods found out there. Here's a photo of an actual working prototype that I completed this past February. Please forgive the poor gluing job. I don't know what it is about me, but I always manage to get glue everywhere including most of my fingers. ANYWAY, this cable is completely plug-n-play, so no modding (provided you have an SNS-001) and no external power required. I'm trying to go into production on these, but that could be a ways off since I'm creating cables for other systems too. Right now I'm working on building a website instead of the placeholder I currently have. Just yesterday, I finished recording a side-by-side composite/component comparison video for Sega Genesis. I'll do a SNES one in the coming weeks and it'll be a 3-screener comparing composite, s-video, and component. Bah, this post is getting too long. Sorry. Bottom-line: You don't have to mod your SNES to get high quality component video output.

If you're more interested in mods, hear what NightWolve has to say. He's a good guy and knows what he's doing.

WillTheDestructor88
Posts: 2
Joined: Wed Jul 31, 2013 1:41 pm

Re: YPbPr ouput mod for SNES consoles

Post by WillTheDestructor88 » Wed Jul 31, 2013 1:55 pm

Hi, I am new around here but I have dabbled in console modding for some time. Anyway, I have a SNES that is the SHVC motherboard revision and the notion of these consoles having the ability to output component video piques my interest. However, I noticed that some schematics for this mod utilize the S-ENC encoder and mine doesn't have this chip. Instead, my SNES has the BA6592F chip, which I understand needs to be amplified before it can be utilized. I have both the NPN and the PNP transistors on hand, as well some 220 uF capacitors and 1k ohm resistors. Am I missing some parts that are needed to perform this mod? Also, is there a different schematic that I need to follow, being that the chip in question is the BA6592F and NOT the S-ENC.

SheepyGuy
Posts: 4
Joined: Wed Feb 27, 2013 6:06 am

Re: YPbPr ouput mod for SNES consoles

Post by SheepyGuy » Thu Aug 01, 2013 6:28 am

BA6592F is what you need to do this, so you're fine. You don't really need amplifiers. Try hooking it up straight; if it looks faded, try adding a 220uF capacitors to the Pb and Pr lines. At this point you'll probably have something that looks good, maybe not quite perfect but close enough. If you want to nitpick and go further, there are plenty of resources in this topic to try.

User avatar
marvelus10
Posts: 243
Joined: Fri Feb 09, 2007 5:01 pm
Location: Nanaimo, BC Canada

Re: YPbPr ouput mod for SNES consoles

Post by marvelus10 » Thu Aug 01, 2013 10:01 am

Ste wrote:Hey, NightWolve. Long time, no speak. I played Celceta at E3 this year. It was pretty sweet. I might have to buy a Vita for that one. Anyway, if you're still hanging around Chicago we should meet up and chat about console video mods.

I don't want to hijack anything here, but once in a while I do Google searches on "SNES component cable". Since I support the Video Game History museum, one can see how I cringe everytime a system is modded for no reason. I decided to actually respond this time since I do have an account here. I know this is a forum of mostly technical people, but would people be interested in mod-less SNES component cables? In addition, I would guarantee that this solution would have higher picture quality than any mods found out there. Here's a photo of an actual working prototype that I completed this past February. Please forgive the poor gluing job. I don't know what it is about me, but I always manage to get glue everywhere including most of my fingers. ANYWAY, this cable is completely plug-n-play, so no modding (provided you have an SNS-001) and no external power required. I'm trying to go into production on these, but that could be a ways off since I'm creating cables for other systems too. Right now I'm working on building a website instead of the placeholder I currently have. Just yesterday, I finished recording a side-by-side composite/component comparison video for Sega Genesis. I'll do a SNES one in the coming weeks and it'll be a 3-screener comparing composite, s-video, and component. Bah, this post is getting too long. Sorry. Bottom-line: You don't have to mod your SNES to get high quality component video output.

If you're more interested in mods, hear what NightWolve has to say. He's a good guy and knows what he's doing.


Maybe you could explain in further detail how this works.

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