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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Thu Nov 14, 2019 4:23 pm 



Joined: 07 Oct 2019
Posts: 25
rama wrote:
PAL or NTSC SNES?

The borti mod board is perfectly fine with the specified capacitors.


It's an NTSC-J SFC GPM-02.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Thu Nov 14, 2019 4:43 pm 



Joined: 08 Mar 2017
Posts: 1364
TheJeffChen wrote:
When disconnecting the original RGB signal from the multi AV port, I turned the original 47uF capacitors around, jumped the other end a little further up the RGB circuit, and then cut the trace between the pad to the multi AV and the old RGB circuit. Before doing this, I tried:
a) removing the original Q4 Q6 Q8 transistors and connect RGB to one of the feet - I got almost no RGB signal at all, only very faint shadows.
b) putting back the transistors, then there was very bad ghosting, looked like reverbs.

Is it possible that the original RGB circuits now need to be terminated with something like a 75 ohm resistor right beside the final decoupling capacitors to prevent signal reflection?


There are no 47uF caps on the mainboard. Did you mean 47nF to ground by chance?
If so, those are ESD protection and don't need to be changed or removed. It's fine either way.

The transistors can't just be removed. You need to redesign the RGB to amplifier path if you do.
As far as I know, there are no instructions for lifted RGB pins into a THS7374 yet.
The best we have right now is the instructions for bortis board that I gave earlier:
https://github.com/borti4938/SNES-AddOn ... 1-reported
(Also check the picture on Assemblergames)

Edit:
So just to be clear, I don't recommend you try any of these.
The ideal solution (lifted RGB pins) has not been developed (yet), and this isn't a trivial thing to do.
It's probably better to accept the noise that's there.
How bad can it be anyway? The console is tuned and uses an RGB bypass of some sorts.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Thu Nov 14, 2019 5:01 pm 



Joined: 07 Oct 2019
Posts: 25
rama wrote:
TheJeffChen wrote:
When disconnecting the original RGB signal from the multi AV port, I turned the original 47uF capacitors around, jumped the other end a little further up the RGB circuit, and then cut the trace between the pad to the multi AV and the old RGB circuit. Before doing this, I tried:
a) removing the original Q4 Q6 Q8 transistors and connect RGB to one of the feet - I got almost no RGB signal at all, only very faint shadows.
b) putting back the transistors, then there was very bad ghosting, looked like reverbs.

Is it possible that the original RGB circuits now need to be terminated with something like a 75 ohm resistor right beside the final decoupling capacitors to prevent signal reflection?


There are no 47uF caps on the mainboard. Did you mean 47nF to ground by chance?
If so, those are ESD protection and don't need to be changed or removed. It's fine either way.

The transistors can't just be removed. You need to redesign the RGB to amplifier path if you do.
As far as I know, there are no instructions for lifted RGB pins into a THS7374 yet.
The best we have right now is the instructions for bortis board that I gave earlier:
https://github.com/borti4938/SNES-AddOn ... 1-reported
(Also check the picture on Assemblergames)

Edit:
So just to be clear, I don't recommend you try any of these.
The ideal solution (lifted RGB pins) has not been developed (yet), and this isn't a trivial thing to do.
It's probably better to accept the noise that's there.
How bad can it be anyway? The console is tuned and uses an RGB bypass of some sorts.


My bad, I was referring to the array of 47pF caps at the multi AV port.

The noise is bad. It's simply too distracting to be playable, although it doesn't show up very well on camera.

One thing I'm not very sure is, I don't remember seeing this noise the first time I hooked this machine up to OSSC, before modding it. I remember the picture was soft and smeared, but not noisy. So this could have something to do with the mod board I guess?


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Thu Nov 14, 2019 5:28 pm 



Joined: 08 Mar 2017
Posts: 1364
47pF, right.
And yes, the mod board installation can cause this, if the input RGB picks up noise through the wiring.
You want short wires for the input into the amplifier, and ideally from points on the mainboard close to PPU-2.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Thu Nov 14, 2019 5:39 pm 



Joined: 07 Oct 2019
Posts: 25
rama wrote:
47pF, right.
And yes, the mod board installation can cause this, if the input RGB picks up noise through the wiring.
You want short wires for the input into the amplifier, and ideally from points on the mainboard close to PPU-2.


I changed the wires for the RGB signal to shielded cables, with the shielding grounded on both ends. However I noticed zero improvement.

The point where I took the signal from was suggested by the guide. Not sure if it's possible to change that.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Fri Nov 15, 2019 2:20 am 



Joined: 07 Oct 2019
Posts: 25
Out of curiosity, I hooked the GPM-02 up with a composite cable and noticed it has the jailbars, bad PSU rolling ripples and probably the diagonal waves on certain pure color scene. Pretty bad :mrgreen:


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Fri Nov 15, 2019 3:56 am 



Joined: 03 Mar 2005
Posts: 438
TheJeffChen wrote:
Out of curiosity, I hooked the GPM-02 up with a composite cable and noticed it has the jailbars, bad PSU rolling ripples and probably the diagonal waves on certain pure color scene. Pretty bad :mrgreen:


What kind of power supply are you using? Do you have an alternate you can test with? (Sorry if you answered this somewhere else already.)

I think that all I did for my GPM-02 was add a 220uf OS-CON and maybe one 1uf ceramic to decouple the power rail. I was using FF6 as a test as well, connected to a BVM via RGB, and the intro and loading screen looked squeeky clean. This was in comparison to a 1CHIP-02 and an APU-01, all without any bypassing. Even the blur compared to the 1CHIP wasn't really all that bad.

Quote:
One thing I'm not very sure is, I don't remember seeing this noise the first time I hooked this machine up to OSSC, before modding it. I remember the picture was soft and smeared, but not noisy. So this could have something to do with the mod board I guess?


If I were you, taking out the board would be the next thing I'd try.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Fri Nov 15, 2019 6:16 am 



Joined: 07 Oct 2019
Posts: 25
SamIAm wrote:
TheJeffChen wrote:
Out of curiosity, I hooked the GPM-02 up with a composite cable and noticed it has the jailbars, bad PSU rolling ripples and probably the diagonal waves on certain pure color scene. Pretty bad :mrgreen:


What kind of power supply are you using? Do you have an alternate you can test with? (Sorry if you answered this somewhere else already.)

I think that all I did for my GPM-02 was add a 220uf OS-CON and maybe one 1uf ceramic to decouple the power rail. I was using FF6 as a test as well, connected to a BVM via RGB, and the intro and loading screen looked squeeky clean. This was in comparison to a 1CHIP-02 and an APU-01, all without any bypassing. Even the blur compared to the 1CHIP wasn't really all that bad.

Quote:
One thing I'm not very sure is, I don't remember seeing this noise the first time I hooked this machine up to OSSC, before modding it. I remember the picture was soft and smeared, but not noisy. So this could have something to do with the mod board I guess?


If I were you, taking out the board would be the next thing I'd try.


I'm using a cheap one from Amazon, 9V center negative. The original one from Japan is off the table since it's making my SFC overheat and shutdown due to over-voltage. I tried another one but it's also a cheap one from Amazon. I did test both with my NESRGB-modded Famicom and there was no noise at all.

I guess I'll start from the 220uF OS-CON. Taking the bypass board off was kinda too much for me, as I already did it once and it was not very fun. I'm afraid I would break the bypass board or even the machine itself if I'd dare to try that again.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Fri Nov 15, 2019 7:09 am 



Joined: 03 Mar 2005
Posts: 438
TheJeffChen wrote:
I'm using a cheap one from Amazon, 9V center negative. The original one from Japan is off the table since it's making my SFC overheat and shutdown due to over-voltage. I tried another one but it's also a cheap one from Amazon. I did test both with my NESRGB-modded Famicom and there was no noise at all.

I guess I'll start from the 220uF OS-CON. Taking the bypass board off was kinda too much for me, as I already did it once and it was not very fun. I'm afraid I would break the bypass board or even the machine itself if I'd dare to try that again.


I don't think the OS-CON is going to do it if the other decoupling caps you added didn't. Don't get me wrong, I understand why you'd want to exhaust all options, but at this point I would try things other than decoupling the 5V rail.

It's a bit odd that the original power supply is causing your system to overheat. The 7805 should be attached to a pretty big heat sink, and the current draw of the SFC is only around 400mA IIRC. The amount of heat generated by the 7805's regulation is basically (excess voltage x current = watts), and a 7805 doesn't even need a heatsink until it is dissipating more than 1.8W. In other words, you should be able to get away with 12V or even 15V on the 7805's input as long as the heatsink is properly attached. Are your power outlets 220-240V? If you're in North America, the original Japanese SFC power supply should be fine.

Also, using a 78S05 shouldn't really be necessary, just FYI. The SFC shouldn't be drawing anywhere near 2A.

Do you have a multimeter? I'd check the 5V rail to make sure it's really 5V, first of all. I'd also be curious to know what the voltage on the input of the 7805 is when the system is on with the original power supply.

Do you get the noise when you use the original power supply during the window before the system overheats? And is this "original" supply an official Nintendo product, or is it something else?

EDIT: If you're in North America and your system is overheating, I bet there is a short somewhere. Once, when I was re-capping one of my systems, I got a little fleck of molten solder on a resistor and only noticed it by dumb luck. It's a good thing I did, too, because it was in fact shorting the resistor. A short on your board could be preventing the power rail from rising to 5V, which could cause all sorts of weirdness, and it would explain your overheating as well as why you didn't see the noise problem emerge until after you installed your bypass board.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Fri Nov 15, 2019 5:17 pm 



Joined: 07 Oct 2019
Posts: 25
SamIAm wrote:
TheJeffChen wrote:
I'm using a cheap one from Amazon, 9V center negative. The original one from Japan is off the table since it's making my SFC overheat and shutdown due to over-voltage. I tried another one but it's also a cheap one from Amazon. I did test both with my NESRGB-modded Famicom and there was no noise at all.

I guess I'll start from the 220uF OS-CON. Taking the bypass board off was kinda too much for me, as I already did it once and it was not very fun. I'm afraid I would break the bypass board or even the machine itself if I'd dare to try that again.


I don't think the OS-CON is going to do it if the other decoupling caps you added didn't. Don't get me wrong, I understand why you'd want to exhaust all options, but at this point I would try things other than decoupling the 5V rail.

It's a bit odd that the original power supply is causing your system to overheat. The 7805 should be attached to a pretty big heat sink, and the current draw of the SFC is only around 400mA IIRC. The amount of heat generated by the 7805's regulation is basically (excess voltage x current = watts), and a 7805 doesn't even need a heatsink until it is dissipating more than 1.8W. In other words, you should be able to get away with 12V or even 15V on the 7805's input as long as the heatsink is properly attached. Are your power outlets 220-240V? If you're in North America, the original Japanese SFC power supply should be fine.

Also, using a 78S05 shouldn't really be necessary, just FYI. The SFC shouldn't be drawing anywhere near 2A.

Do you have a multimeter? I'd check the 5V rail to make sure it's really 5V, first of all. I'd also be curious to know what the voltage on the input of the 7805 is when the system is on with the original power supply.

Do you get the noise when you use the original power supply during the window before the system overheats? And is this "original" supply an official Nintendo product, or is it something else?

EDIT: If you're in North America and your system is overheating, I bet there is a short somewhere. Once, when I was re-capping one of my systems, I got a little fleck of molten solder on a resistor and only noticed it by dumb luck. It's a good thing I did, too, because it was in fact shorting the resistor. A short on your board could be preventing the power rail from rising to 5V, which could cause all sorts of weirdness, and it would explain your overheating as well as why you didn't see the noise problem emerge until after you installed your bypass board.


Thanks for the hint on a short. I checked both the cheap Amazon one and the original one.

In both cases, the 5V rail was a steady 5.02V. So there was probably no short at the moment.

However the original Japanese PSU was outputting over 16V with no load and 12.3V when plugged into the SFC, although it's only supposed to output 10V. The 78S05 started warming up quite noticeably at 12.3V. I could only imagine that this kind of over-voltage pushed the 25yo stock 7805 quite hard. I remember testing with the original PSU and without a heat sink, and the 7805 actually burnt my finger.

With the 9V one, both the 7805 and the 78S05 stayed cool all the time.

I'm in North America btw. Our voltage is 120V while in Japan it's only 100V. So for old non-switching PSU, it could easily over-voltage the output from my understanding. The SFC could literally only work for 10 mins and then started acting like some kind of short happened with the stock PSU. I could feel the back of the machine was too warm to be normal. With the 9V one, it never did that again, and the machine was cool all the time.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sat Nov 16, 2019 2:13 am 



Joined: 03 Mar 2005
Posts: 438
TheJeffChen wrote:
Thanks for the hint on a short. I checked both the cheap Amazon one and the original one.

In both cases, the 5V rail was a steady 5.02V. So there was probably no short at the moment.

However the original Japanese PSU was outputting over 16V with no load and 12.3V when plugged into the SFC, although it's only supposed to output 10V. The 78S05 started warming up quite noticeably at 12.3V. I could only imagine that this kind of over-voltage pushed the 25yo stock 7805 quite hard. I remember testing with the original PSU and without a heat sink, and the 7805 actually burnt my finger.

With the 9V one, both the 7805 and the 78S05 stayed cool all the time.

I'm in North America btw. Our voltage is 120V while in Japan it's only 100V. So for old non-switching PSU, it could easily over-voltage the output from my understanding. The SFC could literally only work for 10 mins and then started acting like some kind of short happened with the stock PSU. I could feel the back of the machine was too warm to be normal. With the 9V one, it never did that again, and the machine was cool all the time.


Huh. I've used a 12V switching supply with a Japanese Super Famicom and had it get plenty warm, but never overheat. Maybe it's just a difference of ambient temperature or something.

Anyway, if the 7805 isn't getting particularly hot with 9V, then there probably isn't a short anywhere.

If you're feeling brave, you could post a high-res pic of your board, complete with the bypass board. Something might stand out to someone that isn't quite standing out to you. Don't worry about any sloppiness; nobody expects your work to be beautiful unless you're selling it.

Beyond that, I'm feeling stumped. The noise still existed when you used your original Japanese supply, right?


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sat Nov 16, 2019 6:23 am 



Joined: 07 Oct 2019
Posts: 25
SamIAm wrote:
Huh. I've used a 12V switching supply with a Japanese Super Famicom and had it get plenty warm, but never overheat. Maybe it's just a difference of ambient temperature or something.

Anyway, if the 7805 isn't getting particularly hot with 9V, then there probably isn't a short anywhere.

If you're feeling brave, you could post a high-res pic of your board, complete with the bypass board. Something might stand out to someone that isn't quite standing out to you. Don't worry about any sloppiness; nobody expects your work to be beautiful unless you're selling it.

Beyond that, I'm feeling stumped. The noise still existed when you used your original Japanese supply, right?


https://i.imgur.com/JgZQ2hJ.jpg
https://i.imgur.com/QhNxBKF.jpg

I'm not afraid of ppl picking on my soldering job, since I'm only a beginner anyways :P

The noise happened before any of the modding, and none of the modding I made had any effect, simply no change at all. Changing the PSU didn't have any effect on the noise either.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sat Nov 16, 2019 6:19 pm 



Joined: 27 Sep 2019
Posts: 18
The culprit could be the mod board if the noise wasn't visible before you installed it. It could cause a phase shift, which would affect where the OSSC is sampling the pixels. Optimal sampling mode is more sensitive to these kinds of things. Try playing around with sample phase and maybe the LPF (switch between SDTV and EDTV).

On a side note, I am not quite sure why the instructions require trace cutting for NTSC consoles. If I understood the design correctly, the two resistors (1870 and 750 ohms) do 10.86 dB attenuation on the signal after being buffered by the two PNP transistors, and then it goes straight into the mod board after that since the trace to the multi-out pin is cut. A possible alternative is to simply remove the resistor pairs (R8, R9), (R13, R14), (R18, R19) and then solder the RGB wires to the node between (R10, R11), (R15, R16) and (R20, R21) for RGB respectively. These resistors already do 10.88 dB attenuation for the S-ENC video encoder, and taking the other resistors out of circuit effectively "cuts" the path to and from the multi-out pins. DC shift isn't an issue either because it is AC coupled and subsequently DC restored before going into the THS7374. Anyone know if this is a good alternative method?

Edit: Then again, I think you need a VCC source to the PNP transistor? I still don't know how they work exactly :)


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Nov 17, 2019 1:45 am 



Joined: 03 Mar 2005
Posts: 438
TheJeffChen wrote:
https://i.imgur.com/JgZQ2hJ.jpg
https://i.imgur.com/QhNxBKF.jpg

I'm not afraid of ppl picking on my soldering job, since I'm only a beginner anyways :P


Cool. Well, nothing jumps out at me, but I'm not the best person to ask since I have no experience with the bypass mod.

Did you follow the instructions for the SHVC-CPU-01 board from this guide? I see that it only says that the procedure is probably the same for the "GBM" 01/02. This could definitely be related to your issue.

Quote:
The noise happened before any of the modding, and none of the modding I made had any effect, simply no change at all.


You had previously expressed uncertainty about this. Whether or not there was noise before the mod would greatly impact the next course of action:

1. If there was possibly no noise before the mod, you should definitely reverse the mod, even if only partially, and check.

2. If there was noise before the mod, you'll have to look for another fix or simply accept that this is a noisy board.

I looked at your pics again, and there's just no way my GPM-02 was that noisy. If I get some time, I suppose I could dig it out and test it again, though. Is the FF6 menu/loading screen the noisiest screen you've seen? You've said that blue is actually the least noisy of the RGB channels. I have an Everdrive and can test most anything that's easy to reach, so let me know if you have any recommendations.

I don't suppose that resettable fuse you added could be the culprit? It doesn't seem like it should be, but taking it off and bridging that connection with wire (for testing purposes only) is something I'd try before abandoning the system.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Nov 17, 2019 2:41 am 



Joined: 07 Oct 2019
Posts: 25
SamIAm wrote:
Did you follow the instructions for the SHVC-CPU-01 board from this guide? I see that it only says that the procedure is probably the same for the "GBM" 01/02. This could definitely be related to your issue.


Yes, I followed this one to the letter. That's why I went and cut the traces, which were below the bypass board and you can only see a hint of it on the photo.

SamIAm wrote:
I don't suppose that resettable fuse you added could be the culprit? It doesn't seem like it should be, but taking it off and bridging that connection with wire (for testing purposes only) is something I'd try before abandoning the system.


No, that fuse was a casualty in the process of me wrestling the noise. Machine plugged in and the bottom of the switch touched the metal shielding on the board. Pop and spark. Luckily I had 9 extras from my Dreamcast mod so it's an instant fix :P

=========

Today I finally managed to move the TV into the house. Tested the SFC on the CRT and the CPU noise is actually extremely faint, to the point of that I can only find traces of them in the menu screen of FF6. Some other faint noise showed up but I suppose it could be the PSU instead (sections of horizontal fast twitching wavy lines).

On OSSC, the noise is always visible. It changes shape when the CPU is doing different stuff. The worst case is the opening scene when the screen is scrolling down, and the transition to black right after you load a file, as well as the menu screen whenever you open it up.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Nov 17, 2019 3:56 am 



Joined: 03 Mar 2005
Posts: 438
TheJeffChen wrote:
Today I finally managed to move the TV into the house. Tested the SFC on the CRT and the CPU noise is actually extremely faint, to the point of that I can only find traces of them in the menu screen of FF6. Some other faint noise showed up but I suppose it could be the PSU instead (sections of horizontal fast twitching wavy lines).

On OSSC, the noise is always visible. It changes shape when the CPU is doing different stuff. The worst case is the opening scene when the screen is scrolling down, and the transition to black right after you load a file, as well as the menu screen whenever you open it up.


Interesting.

With an APU system running FF6 on a BVM via RGB, I was able to clearly see the CPU spinning pattern in the purple sky in the intro, and when the FF6 logo appeared, a whole bunch of other noise also appeared around it. Then, with a GPM-02 system in the exact same situation, there was simply no noise that I remember detecting at all. I didn't check the menu, however, so maybe I'll look into that when I get the chance.

If you have an unused high-ish value ceramic cap sitting around, sticking it between the 7805's input and ground on the bottom of the board (much like you've got that 220uf electrolytic between the output and ground) might alleviate any high-frequency noise from your switching PSU.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sat Dec 07, 2019 7:24 pm 


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Is there possibility for a UN3076xxxxx to be a 1-Chip?

Researching serials again today, I saw some guy on reddit claiming that in his experience, "all UN308xxxxxx's are 1-Chips and some UN307xxxxxx's are 1-Chip as well".

Anyone got a 1-Chip in that range by any chance? (maybe someone here does and hasn't entered it in the database yet.)

(or maybe that guy on reddit is just lying for attention :lol: )
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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Dec 08, 2019 12:13 pm 


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I always only looked for UN31 or higher when searching.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Feb 16, 2020 8:07 pm 


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I don't have a 1chip SNES. Mine is a SNS-CPU-GPM-01. Will I see any meaningful improvement if I buy a SCART cable for it?


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Feb 16, 2020 8:13 pm 



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geiger9 wrote:
I don't have a 1chip SNES. Mine is a SNS-CPU-GPM-01. Will I see any meaningful improvement if I buy a SCART cable for it?


RGB is better than S-Video, much better than Composite and much much better than RF. So the answer is a big yes.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Sun Feb 16, 2020 8:25 pm 


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H6rdc0re wrote:
geiger9 wrote:
I don't have a 1chip SNES. Mine is a SNS-CPU-GPM-01. Will I see any meaningful improvement if I buy a SCART cable for it?


RGB is better than S-Video, much better than Composite and much much better than RF. So the answer is a big yes.


Yeah, I know about the hierarchy of connections but I guess I was concerned in this case because of the limitations on my SNES. If I had a 1chip I would absolutely order the SCART cable no questions asked.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Mon Feb 17, 2020 6:43 am 



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geiger9 wrote:
H6rdc0re wrote:
geiger9 wrote:
I don't have a 1chip SNES. Mine is a SNS-CPU-GPM-01. Will I see any meaningful improvement if I buy a SCART cable for it?


RGB is better than S-Video, much better than Composite and much much better than RF. So the answer is a big yes.


Yeah, I know about the hierarchy of connections but I guess I was concerned in this case because of the limitations on my SNES. If I had a 1chip I would absolutely order the SCART cable no questions asked.


What connection are you currently using and with which scaler or display?


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Mon Feb 17, 2020 12:14 pm 


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H6rdc0re wrote:
What connection are you currently using and with which scaler or display?


Currently using s-video on a JVC i'Art CRT. I had planned on using a SCART to YPbPr transcoder with the CRT.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Mon Feb 17, 2020 3:03 pm 


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Honestly, unless you're going with rgb scart for every (or at least other) system, SNES S-video is like 90% what you'll get by upgrading. My recollection with 1 vs 2 chip s-video on a consumer CRT is that there's a negligible difference. With RGB there's only a tiny bit more difference but that only shows with higher TVL CRTs.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Mon Feb 17, 2020 3:05 pm 


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Also, if you can get a decent photo of it people here can chime in on if there's much more you can expect.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Mon Feb 17, 2020 6:22 pm 


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geiger9 wrote:
H6rdc0re wrote:
What connection are you currently using and with which scaler or display?


Currently using s-video on a JVC i'Art CRT. I had planned on using a SCART to YPbPr transcoder with the CRT.


Just be aware that certain original model SNES units have notoriously bad RGB out. My old one actually has a bad white bleed to the right of things like text, etc. when using RGB. S-Video is much, much sharper. I dont know if its some bad / old caps in the path from the video dac to the multi out or what, but its no bueno. Just beware.

However, if your unit has good RGB, you get only a miniscule increase in sharpness but very noticeably richer, more vibrant color.


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Tue Feb 18, 2020 8:34 am 


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geiger9 wrote:
H6rdc0re wrote:
What connection are you currently using and with which scaler or display?


Currently using s-video on a JVC i'Art CRT. I had planned on using a SCART to YPbPr transcoder with the CRT.

Or you can buy the HD Retrovision component cables.
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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Tue Feb 18, 2020 6:17 pm 



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Posts: 158
geiger9 wrote:
H6rdc0re wrote:
What connection are you currently using and with which scaler or display?


Currently using s-video on a JVC i'Art CRT. I had planned on using a SCART to YPbPr transcoder with the CRT.


No need to change. Just keep using S-video, that still produces a good picture. Some advise nobody ever gave me, save your money or spend it on games or something else. Going for the best picture quality is almost like some kind of obsession and you'll end up spending too much money and changing equipment too often. Trust me I know... :(


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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Wed Feb 19, 2020 10:47 pm 


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Einzelherz wrote:
Also, if you can get a decent photo of it people here can chime in on if there's much more you can expect.


Jus to recap, this is the image I get on a JVC D series from my SNES (motherboard revision SNS-CPU-GPM-01) using a well made s-video cable. I'm wondering if it's worth my while to buy a SCART cable for my SNES or is this picture pretty much as good as it gets with my particular mobo revision.

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 Post subject: Re: SNES/Famicon PCB Revisions and RGB Video
PostPosted: Thu Feb 20, 2020 1:02 pm 


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You might see a tiny, very small bit of up close crispness, but from playing distance it'll be practically identical. Remember, the only difference (technically?) between svideo and rgb is that the colors travel on separate lines. The sync is separate on both and that's where most of the sharpness lives.


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