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GameSX.com => RGB + Video Discussions => Topic started by: Link83 on April 29, 2008, 10:31:00 PM

Title: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on April 29, 2008, 10:31:00 PM
Hi everyone,

I hope this is ok to ask here - I have searched the GamesX site but couldnt find all the info I was looking for.

I am trying to find pictures/information about the the internal wiring of all the Official Nintendo AV cables for both the NTSC and PAL SNES, N64 and Gamecube consoles

I am just curious to know what resistors and capacitors Nintendo 'officially' used in their cables, and how they were wired up.

I believe all the Composite AV cables and S-Video cables are the same for each region, is this correct?

Im am quite new to modding so please forgive me if I have stuff wrong, or am asking obvious questions.

COMPOSITE AV CABLES

As I understand it the only difference is that PAL composite AV cables have a resistor between video and ground inside the console end of the cable, whereas the NTSC versions do not. I have read 75 ohms is the value to use, but am curious to know if this is what the official nintendo cable uses/has inside?

UPDATE:-
I managed to find my Official PAL Nintendo Composite cable and there appears to be more than just a resistor - there is also a 220uf capacitor aswell - anyone care to explain whats going on!
Heres an official NTSC GC Composite cable:-
(http://img518.imageshack.us/img518/81/gccompositentscmt0.th.jpg) (http://img518.imageshack.us/my.php?image=gccompositentscmt0.jpg)

and heres the PAL GC Composite cable:-
(http://img518.imageshack.us/img518/953/gccompositepal1bn0.th.jpg) (http://img518.imageshack.us/my.php?image=gccompositepal1bn0.jpg)(http://img518.imageshack.us/img518/988/gccompositepal2qp4.th.jpg) (http://img518.imageshack.us/my.php?image=gccompositepal2qp4.jpg)(http://img518.imageshack.us/img518/2462/gccompositepal3id7.th.jpg) (http://img518.imageshack.us/my.php?image=gccompositepal3id7.jpg)
(http://img518.imageshack.us/img518/7457/gccompositepal4ve9.th.jpg) (http://img518.imageshack.us/my.php?image=gccompositepal4ve9.jpg)(http://img518.imageshack.us/img518/2677/gccompositepal5zh5.th.jpg) (http://img518.imageshack.us/my.php?image=gccompositepal5zh5.jpg)

would love to know exactly how they differ/what the capacitor and resistor are for.

I havent checked to see if my PAL SNES/N64 Composite cable is different again but I will dig it out soon.

S-VIDEO CABLES

In all my searches I have never come across an official PAL S-Video cable - was one ever made? and if so does anyone have any pictures of it, and the insides?

I have read that to make a PAL S-video cable you need to add resistor(s) to an NTSC S-video cable, but have read conflicting advise that you either need to 1)Connect one 75ohm resistor between luma and ground, or 2)Put 75ohm resistors on both the luma and ground lines (not between them)

Which is right?

RGB SCART CABLES
Also, when it comes to the official RGB Scart cable things seem to get quite abit more confusing. There are two official RGB scart cables that I know of - one for the PAL Gamecube, and one for the Japanese Super Famicom. Theres rumours that there was an official RGB Scart lead for the PAL SNES but I have never seen it.

The PAL Gamecube scart cable has four 220uf capacitors and one resistor. There is a capacitor on red, green and blue, but am not sure what the last one connects to? Heres a pic of the resistor:-
(http://img170.imageshack.us/img170/1149/gcrgbscart003ar2.th.jpg) (http://img170.imageshack.us/my.php?image=gcrgbscart003ar2.jpg)

Can anybody tell me what value resistor it uses? I guess its 180ohm. I have tried to work it out by the color banding but am not very good at it!

I have found a schematic here:-
http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm#gamecube
but it doesnt seem to match the layout of the official RGB cable:-
(http://img170.imageshack.us/img170/6220/gcrgbscart032px5.th.jpg) (http://img170.imageshack.us/my.php?image=gcrgbscart032px5.jpg)
Is shows an extra wire and 75ohm resistor to pin 18, when there is none on the official cable, and it also has no wire to pin 17 where there is one on the official cable!

Also, I know the PAL SNES doesnt need the red, green and blue capacitors, but does it still need the last capacitor and the resistor?

and what about the NTSC N64 when RGB modded - does that need any capacitors or resistors or not?

Lastly, I have read that when building a PAL SNES RGB Scart cable, once the capacitors are removed the image can be too bright. Some people add resistors to the red, green and blue lines, but what value is correct to use? I have read of people using 30ohm, 33ohm and 47ohm resistors and some using none at all! Who is right? What makes the brighness level perfect/normal?


Lastly, out of curiousity does anybody know how the RGBJ Scart cable for the Super Famicom was wired up? Or does anyone have pictures of its internals? For those that have never heard of it heres a picture of what it looks like:-
(http://img170.imageshack.us/img170/23/sfcrgbboxle2.gif)
(It is still available from the site whos photo it is tagged from)

I imagine inside it would look similar to the PAL Gamecube RGB Scart cable but it would be intererested to know for sure.

Many thanks in advance  ;D
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: l_oliveira on May 02, 2008, 05:33:08 PM
I think the cable is the same but the pinout on the 21 pin connector is different from SCART.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: Codeman on May 09, 2008, 08:47:27 PM
I would also like to know more about these RGB cables for Nintendo systems, I already asked in my previsou thread about a Dragon Cable but got no reply

ill ask again

I assume a PAL GC would need all the caps on the RGB pins, correct?

a PAL SNES doesnt need the RGB caps, correct?

the 4th capacitor you mentioned is connected to the Composite/Sync pin, correct?

assuming I have a RGB modded N64, which cable should I user? A SNES cable without caps or a GC cable with caps?


Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: albino_vulpix on May 10, 2008, 03:49:33 PM
Quote from: Codeman on May 09, 2008, 08:47:27 PM
I would also like to know more about these RGB cables for Nintendo systems, I already asked in my previsou thread about a Dragon Cable but got no reply

ill ask again

I assume a PAL GC would need all the caps on the RGB pins, correct?
Correct

a PAL SNES doesnt need the RGB caps, correct?
Correct

the 4th capacitor you mentioned is connected to the Composite/Sync pin, correct?
Yes, the scart cables have the resistor and capacitor on the composite video signal, just like in the PAL AV cables.

assuming I have a RGB modded N64, which cable should I user? A SNES cable without caps or a GC cable with caps?
Use a cable with the caps.


Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: phreak97 on May 13, 2008, 04:19:36 PM
i've tried asking about this stuff before, we should add the known configurations to the wiki then build up from there.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: Codeman on May 13, 2008, 06:58:03 PM
Awesome, thanks for the reply!

I think ill mod my Dragon Cable then! Ill throw a 3-way on/off switch for those capacitors and make it a universal Nintendo cable ^^
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: albino_vulpix on May 13, 2008, 07:19:03 PM
On a slightly related topic, can the pins of a snes/64/cube cable be taken out and repositioned?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: phreak97 on May 13, 2008, 08:00:20 PM
yes, but i seem to remember it wasnt that easy, and you need to sacrifice a cable or two to get enough pins for an rgb cable. assuming thats what youre after.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Alcahest on July 14, 2008, 08:43:02 AM
Here are pictures of the official Nintento RGBJ cable for Super Famicom, SHVC-010
Scart plug side:
http://videoff7.free.fr/shvc010-plug.jpg

another one (sorry for the quality, taken from a jpn site)
http://videoff7.free.fr/shvc010-plug2.jpg

I wish i knew more about the internals of this cable too (capacitor used etc..)
Later,

Alcahest
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: NFG on July 14, 2008, 05:47:55 PM
These cables are very easy to open.  There's a twist-off cap where the connector meets the cable, and you need only compress the four little tabs (push them in towards the cable) and twist the cap one or two rotations, and it will come off, allowing the shell to open.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Alcahest on July 14, 2008, 09:42:40 PM
Yep, I learned that the hard way by opening the official Euro Gamecube RGB cable I received a few days ago.
If anyone has the japanese official SHVC-010 JRGB cable, don't hesitate to post pics!
I am only interested in seeing if RGB sync is taken from Pin3 CSYNC or Pin9 CVBS on the SFC side.
And also if this wire is connected to any resistance/capacitor before reaching the scart end.
I don't really want to spend another 50US$ at ncsx just for this info ^^;
Thanks,

Alcahest
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on July 15, 2008, 08:38:06 AM
I have two (maybe even three) of the SHVC-010 cables.  I didn't check to see where the Euro gamecube RGB cable got it's sync from... since it just "works" on my PVM-2030 with either (CVBS or CSYNC).  But that might explain why connecting the snes with that cable to the Panny plasma's PC input didn't work.... (unless it truly didn't accept CSYNC to begin with).  My first SNES JRGB cable is currently tansformed into a short Scart cable with two female RCAs for auto.... for use with my RGBS to Component converter.  I'll post the answer to the question at hand later tonight....  :-X
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on July 15, 2008, 10:21:41 AM
Wow, surprised to see this thread back up!  :o

Quote from: RGB32E on July 15, 2008, 08:38:06 AM
I have two (maybe even three) of the SHVC-010 cables.  I didn't check to see where the Euro gamecube RGB cable got it's sync from... since it just "works" on my PVM-2030 with either (CVBS or CSYNC).  But that might explain why connecting the snes with that cable to the Panny plasma's PC input didn't work.... (unless it truly didn't accept CSYNC to begin with).  My first SNES JRGB cable is currently tansformed into a short Scart cable with two female RCAs for auto.... for use with my RGBS to Component converter.  I'll post the answer to the question at hand later tonight....  :-X
I would love to see some pictures of the internals of an unmodified SHVC-10 cable if you can?

-------------------------------------------------------------------------------------------------------------------------------------

Also, to anyone who may be interested, I managed to acquire an Official European SNES Scart cable. It seems they are quite rare - as they were only released in France AFAIK. Heres a pic of one new in the packaging, and the one I recieved:-
(http://img255.imageshack.us/img255/5987/frenchsnesscartks2.th.jpg) (http://img255.imageshack.us/my.php?image=frenchsnesscartks2.jpg)(http://img515.imageshack.us/img515/4871/snes040id5.th.jpg) (http://img515.imageshack.us/my.php?image=snes040id5.jpg)

As you can see, it has a grey Scart plug like the Japanese SHVC-10, rather than a black scart plug like the Official Gamecube Scart cable.

Heres pictures from inside the Scart plug:-
(http://img511.imageshack.us/img511/295/snes020rx6.th.jpg) (http://img511.imageshack.us/my.php?image=snes020rx6.jpg)(http://img410.imageshack.us/img410/5673/snes025nz6.th.jpg) (http://img410.imageshack.us/my.php?image=snes025nz6.jpg)(http://img410.imageshack.us/img410/6398/snes018sf3.th.jpg) (http://img410.imageshack.us/my.php?image=snes018sf3.jpg)

Heres some of the circuit board disconnected:-
(http://img362.imageshack.us/img362/92/snes016yb1.th.jpg) (http://img362.imageshack.us/my.php?image=snes016yb1.jpg)(http://img232.imageshack.us/img232/9747/snes010ei6.th.jpg) (http://img232.imageshack.us/my.php?image=snes010ei6.jpg)

and heres the wiring to the Multi AV plug:-
(http://img149.imageshack.us/img149/1403/snes028sd9.th.jpg) (http://img149.imageshack.us/my.php?image=snes028sd9.jpg)(http://img378.imageshack.us/img378/623/snes029uo2.th.jpg) (http://img378.imageshack.us/my.php?image=snes029uo2.jpg)

It has a small circuit board with four components. One is obviously a 100 ohm resistor, however I have no idea what the other three are? (Not seen anything like them before)
They have codes on them which are as follows:-

A124TA F

C124TF F

RS4750J

Googling them came back with nothing  :(

Also, for anyone who may be interested in opening their Official Nintendo Scart Cables I took this picture and added some notes on how best to do it (The notes are abit small I know, but if you save the picture and then open it you can zoom in and read the text  ;)):-
(http://img515.imageshack.us/img515/8364/snes045zm1.th.jpg) (http://img515.imageshack.us/my.php?image=snes045zm1.jpg)

I really think it would be good if someone could add circuit diagrams to the Wiki for all the Official Scart cables out there. I would do it myself but im not that knowledgable on how circuits work (In case you hadnt guessed!) but I would be happy to provide as many pictures of the insides of Official Scart cables as anyone wants.

I know this page is fantastic:-

http://members.optusnet.com.au/eviltim/gamescart/gamescart.htm

and im sure they all work great, but they dont have exactly the same circuits or components as the Official Scart Cables use (As Alcahest noticed in his other thread)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on July 15, 2008, 04:30:29 PM
Well.... I took a look at one of my unmodified SHVC-10 cable and the two ends of the modified one (is a JRGB).... looks like nintendo didn't wire the official JRGB cables to use CSYNC, they use CBVS!  Inside the 21 pin connector, RGB are filtered with 220uf caps, composite video is fed to the CSYNC pin, +5VDC is fed through series 75 ohm resistor to the +5VDC pin (see gamesx JRGB pinout).  GND and audio is fed to the appropriate pins.  I don't have a camera to take pictures, but will try to in the near future.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: NFG on July 15, 2008, 04:57:21 PM
It's actually more common to use Cvid than Csync in an RGB cable, so what you found isn't unusual.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Alcahest on July 15, 2008, 05:40:41 PM
Link83, great thread indeed.  8)
Interesting pics of the PAL SNES official RGB cable.. i wonder indeed what those components are, they're prolly just "housing" 47 ohms resistors for R,G,B & composite pins?

Quote from: RGB32E on July 15, 2008, 04:30:29 PM
Well.... I took a look at one of my unmodified SHVC-10 cable and the two ends of the modified one (is a JRGB).... looks like nintendo didn't wire the official JRGB cables to use CSYNC, they use CBVS!  Inside the 21 pin connector, RGB are filtered with 220uf caps, composite video is fed to the CSYNC pin, +5VDC is fed through series 75 ohm resistor to the +5VDC pin (see gamesx JRGB pinout).  GND and audio is fed to the appropriate pins.  I don't have a camera to take pictures, but will try to in the near future.

Excellent RGB32E, so you confirm that SFC CVBS is not modified in any way before it reaches the TV.. very good to know for my problem ^^ At last i can totally rule out a problem of the cable as even the official Super Famicom one doesn't alter CVBS in any way. (i'm using the official PAL GC RGB cable, seems exactly the same as SHVC-010 after all.)
See you,

Alcahest
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 15, 2008, 11:25:04 PM
Link83,

My SCART cable diagrams sometimes differ from what's inside the official cable. It's mainly because I have very few official SCART cables and have to rely on (often non-technical) contributiors and guess work.

I'd like to draw up a circuit diagram of your cable but I need some more information....first do you own a multimeter (and know how to use it)?

BTW:
A124TA F = PNP transistor
C124TF F = NPN transistor
RS4750J = resistor network with 5% tolerance, the value is a bit ambiguous but probably 47 ohms
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on July 16, 2008, 01:03:01 AM
Quote from: viletim on July 15, 2008, 11:25:04 PM
Link83,

My SCART cable diagrams sometimes differ from what's inside the official cable. It's mainly because I have very few official SCART cables and have to rely on (often non-technical) contributiors and guess work.
Hi!
I hope you dont think I was criticizing you in any way - You have done fantastic work drawing up all those diagrams. I just think it might be useful to have circuit diagrams of the official scart cables aswell if possible :)

Quote from: viletim on July 15, 2008, 11:25:04 PM
I'd like to draw up a circuit diagram of your cable but I need some more information....first do you own a multimeter (and know how to use it)?

BTW:
A124TA F = PNP transistor
C124TF F = NPN transistor
RS4750J = resistor network with 5% tolerance, the value is a bit ambiguous but probably 47 ohms

Ah thats interesting - do you think there is any way for us to work out the values of the transistors?

I have a digital multimeter and know roughly how to use it - im no expert though, but if you tell me what settings to place the dial on and where to put the probes I can gladly tell you the read out.

Although if you'd like I would gladly send the scart cable to you and you could draw up the circuit diagram and send it back whenever you have finished with it?

I have quite a few official scart cables aswell if your interested, heres a list:-
Official SNES Scart cable
Official Gamecube Scart cable
Official Dreamcast Scart cable
Official Xbox Scart cable
...and am hoping to acquire an Official Mega Drive 2 Scart cable aswell
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on July 16, 2008, 02:04:08 AM
Quote from: Lawrence on July 15, 2008, 04:57:21 PM
It's actually more common to use Cvid than Csync in an RGB cable, so what you found isn't unusual.

It's a surprise to me!  :o  I just checked out the official gamecube scart cable that I reterminated for the PVM DB25 and found that it carries both composite (filtered by a 220uf cap) and CSYNC over the cable.  Hence, its the modders choice to use either!  So, looks like I'll be making a minor change in my cable (remove filtered composite and replacing with CSYNC on the DB25F connector).  R, G, B, and composite are filtered with 220uf caps (as pictured by Link) on the PCB.  CSYNC is just routed from one header on the PCB to another (with wire ready for soldering)....

I forgot about this.... even though it isn't necessarily applicable to the SFC, but makes sence in case PAL snes is used with Japanese 21 pin RGB cable:

"A PAL SNES outputs +12v on pin 3, not composite sync. This is for a SCART TV to automatically detect RGB input."
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on July 16, 2008, 02:16:06 AM
Quote from: Alcahest on July 15, 2008, 05:40:41 PM
(i'm using the official PAL GC RGB cable, seems exactly the same as SHVC-010 after all.)

The PAL GC RGB and SHVC-010 are not quite the same... Since you are using the official GCN SCART cable, you have the choice of using filtered composite or composite sync (both are fed through the scart plug PCB).  Which signal are you using as sync?  Either choice of sync (filtered CVBS or CSYNC) will work fine on a Sony PVM, but not necessarily on other monitors or RGBS accepting devices.

Some similarities between official SFC RGB and official GCN SCART cables:
-R, G, and B are filtered with 220uf caps
-CVBS is fed through the cable

Differences:
-Both CVBS and CSYNC (or +12VDC for PAL systems) are fed through the GCN cable (only CVBS is wired/used on SFC RGB cable)
-CVBS is filtered with a 220uf cap on the GCN cable (CVBS is not filtered on SFC RGB cable)
-GCN cable uses 100 ohm resistor for the SCART mode setting and the SFC connects VDC through series 75 ohm resistor to the +5VDC pin of 21 pin connector.

I hope this helps....  ???
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Alcahest on July 16, 2008, 08:32:27 AM
Quote from: RGB32E on July 16, 2008, 02:16:06 AM
The PAL GC RGB and SHVC-010 are not quite the same... Since you are using the official GCN SCART cable, you have the choice of using filtered composite or composite sync (both are fed through the scart plug PCB).  Which signal are you using as sync?

I've tried both and even Chroma, separately, together, i tried everything  ;D
Flaw is there on all of them. Flaw is there with composite regardless if it is filtered or not too.

Quote
Either choice of sync (filtered CVBS or CSYNC) will work fine on a Sony PVM, but not necessarily on other monitors or RGBS accepting devices.

Some similarities between official SFC RGB and official GCN SCART cables:
-R, G, and B are filtered with 220uf caps
-CVBS is fed through the cable

Differences:
-Both CVBS and CSYNC (or +12VDC for PAL systems) are fed through the GCN cable (only CVBS is wired/used on SFC RGB cable)
-CVBS is filtered with a 220uf cap on the GCN cable (CVBS is not filtered on SFC RGB cable)
-GCN cable uses 100 ohm resistor for the SCART mode setting and the SFC connects VDC through series 75 ohm resistor to the +5VDC pin of 21 pin connector.

I hope this helps....  ???

Yes majorly  ;D
It proves 100% that what I experience is not a cable issue.
Thanks for all those details. Pretty much all is known about SNES/SFC cables now :D
See you,

Alcahest
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 16, 2008, 01:38:50 PM
Link83,

Here's what needs to be done for the SNES SCART cable:

1) Set your multimeter to continuity test (beeps when you touch the probes together) and find out which pins of the scart socket connect to which pins of the PCB.
2) Measure the resistors - the resistor network is four resistors connected inside a signle package. They all have one leg connected together which is marked with a dot. So measuring the resistance between the dot leg and any other leg should give the correct value.
3) Work out the pinout of the transistors. This is a bit tricky... First set the meter to diode test mode (in some cheap meters diode test and continuity mode are the same). The NPN transistor looks like two diodes with their cathodes connected. Place the red probe on any pin and the black probe on another, is there a reading on the display (500-700mV drop usualy)? If so then place the black probe on the other leg and check if it too has a forward voltage drop. If not, then move the red probe to another pin and repeat. If both pins do then the pin the red probe is on is the BASE, the one with the highest voltage drop (it may only be a few milivolts higher) is the EMITTER, and the other is the COLLECTOR. The PNP transistor works the same way except the red and black probes are exchanged.

RGB32E,
The series capacitor sometimes found in SCART cables is not part of a filter. There is no (intential) filtering going on, its purpose is just to pass the AC signal withough disturbing the DC level. Its a coupling capacitor and the signal is coupled through the capacitor.

And why would you be surprised that composite video (CVBS) is normal connected to the composite video out pin of the SCART plug??? It's a video input, not a digital sync input. The two are not the same electricaly. Sort of, but not quite, like the difference between the signal output of a CD player and a power amplifier. Both signals carry the same information but are meant for different purposes.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on July 17, 2008, 01:08:22 AM
Quote from: viletim on July 16, 2008, 01:38:50 PM
Its a coupling capacitor and the signal is coupled through the capacitor.
Sure.... works for me... so why were you using 180 ohm resistors again in your cables?

Quote from: viletim on July 16, 2008, 01:38:50 PM
And why would you be surprised that composite video (CVBS) is normal connected to the composite video out pin of the SCART plug??? It's a video input, not a digital sync input.
I don't believe I typed anything like that... read what I wrote again.  I was surprised that the "Official" Japanese SFC RGB cable does not use pin 3 (CSYNC/+12VDC on the snes multi-av connector) for obtaining the sync (uses composite video instead of CSYNC).  I'm sorry you didn't understand that...  :'(
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Alcahest on July 17, 2008, 04:50:51 AM
viletim, do you have any idea what a PNP transistor and a NPN transistor are doing in the EURO SNES RGB cable?  :o
Is it possible that the JRGB input on JPN TVs and RGB input on EURO TVs are not exactly similar when it comes to their expected incoming signals? (voltage levels..)

RGB32E, isn't it just a matter of falling back to composite if tv can't process RGB? (for the sake of Japanese tv retrocompatibility), like we have in europe?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on July 17, 2008, 05:06:43 AM
Quote from: Alcahest on July 17, 2008, 04:50:51 AM
RGB32E, isn't it just a matter of falling back to composite if tv can't process RGB? (for the sake of Japanese tv retrocompatibility), like we have in europe?

Yeah... that's completely plausible...  :-\  I've seen it happen on a RCA brand television (NTSC) that had a euroconnector (SCART) on it.  When feeding RGBcvS to it, it fell back to composite... and I decided to give the TV away to a friend in need...  ;)  I haven't seen encountered it on a JRGB TV... but I wouldn't be surprised about that. :P  Man... SCART is a pain!
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on July 17, 2008, 05:12:52 AM
Well I think i found the 'dot' point, if it is the dot on the left in this picture:-
(http://img369.imageshack.us/img369/6265/snes008op2.th.jpg) (http://img369.imageshack.us/my.php?image=snes008op2.jpg)
I measured the resistance between that 'dot' point (Which is connected to gound) and the other four points (R, G, B, and Composite). I was expecting it to say 47 ohms (especially since the RS4750J code printed on it has a '47' in it) but it in fact said 75 ohms! (Perhaps the code actually meant 4x75ohm resistors?)

So does that mean there should be 75 ohms resistors on the R, G, B, and Composite lines of a PAL SNES Scart cable, or does it make a difference that its a resistor network (not individual resistors) with one leg connected to ground?

Heres some closer pictures of the two transistors showing the codes:-
(http://img378.imageshack.us/img378/3764/snes001bf2.th.jpg) (http://img378.imageshack.us/my.php?image=snes001bf2.jpg)(http://img372.imageshack.us/img372/9656/snes004bn1.th.jpg) (http://img372.imageshack.us/my.php?image=snes004bn1.jpg)

I was trying to work out which was the base, emitter and collector for each transistor and drew up this diagram with paint on the circuit board:-
(http://img175.imageshack.us/img175/4599/snesrgbscartpaintba6.th.jpg) (http://img175.imageshack.us/my.php?image=snesrgbscartpaintba6.jpg)

It looks like the two transistors are only connected to +12v, +5v and Ground - so perhaps they are only important for scart auto-switching. I dont undertand why these transistors are necessary though?

I would still be happy to make any readings I can if you could tell me/mark which points are the base, collector and emitter?

Also, if  it helps at all here is a picture of my Digital MultiMeter:-
(http://img254.imageshack.us/img254/324/multimeterzs7.th.jpg) (http://img254.imageshack.us/my.php?image=multimeterzs7.jpg)
According to the instructions it has a setting specifically for transistors called 'hFE' - no idea how to use it though or if it would help!
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 17, 2008, 02:32:26 PM
Link83,

That diagram is really helpful!

Ok, 4*75 ohm resistors, that sounds more like Nintendo... These transistors are "digital", meaning that they have one or more resistors inside. Full part numbers would be DTA124TA and DTC124TF. I've got the datasheet, drawn a circuit. It's actual purpose has me completely befuddled though...

I need some active measurements. Plug everything in (cable, nintendo, TV), switch it all on and measure the voltage (with respect to ground) on:
1) the +12v line coming from the SNES (lets see what it really is)
2) pin 8 of the SCART connector
3) pin 16 of the SCART connector

And a couple of passive ones:
Then switch everything off and measure the resistance between pin 8 of the SCART connector and ground (this is actually a measurement of your TV). Now disconnect the cable from everything and measure the resistance between the +12v line coming from the SNES and pin 8 of SCART.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: MKL on July 18, 2008, 12:41:48 AM
Quote from: viletim on July 15, 2008, 11:25:04 PM
My SCART cable diagrams sometimes differ from what's inside the official cable. It's mainly because I have very few official SCART cables and have to rely on (often non-technical) contributiors and guess work.

So where did you get the idea that the RGB lines needed a 47ohm resistance? I never noticed an overly bright picture without any resistance (and in any case 47ohm wouldn't be enough to make a really noticeable difference) and the official cable now confirms no resistors should be put in the RGB lines. The 75ohm resistors to ground have a parallel with the CVBS one which makes sense.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 19, 2008, 07:22:39 PM
Quote from: MKL on July 18, 2008, 12:41:48 AM
Quote from: viletim on July 15, 2008, 11:25:04 PM
My SCART cable diagrams sometimes differ from what's inside the official cable. It's mainly because I have very few official SCART cables and have to rely on (often non-technical) contributiors and guess work.

So where did you get the idea that the RGB lines needed a 47ohm resistance? I never noticed an overly bright picture without any resistance (and in any case 47ohm wouldn't be enough to make a really noticeable difference) and the official cable now confirms no resistors should be put in the RGB lines. The 75ohm resistors to ground have a parallel with the CVBS one which makes sense.


Va = 1.4Vpp (measured)
Vb should be 0.7Vpp (video standard)

R1 is inside all PAL Super Nintendos
R3 is inside all SCART TVs

What Nintendo did: 
Va--[R1]--+---------+--- Vb
     30   |         |
         [R2]      [R3]
          |75       |75
          +---------+--- Ground
Vb = 1.4 / (30 + 75//75) * 75//75 = 0.77Vpp

What I did: 
Va--[R1]----[R2]----+--- Vb
     30      47     |
                   [R3]
                    |75
                    +--- Ground
Vb = 1.4 / (30 + 47 + 75) * 75 = 0.69Vpp

What you advocate:
Va--[R1]------------+--- Vb
     30             |
                   [R3]
                    |75
                    +--- Ground
Vb = 1.4 / (30 + 75) * 75 = 1.00Vpp
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: MKL on July 20, 2008, 12:05:51 AM
Thanks. I've never spent too much time to figure out the SNES video output circuitry due to traces being hard to follow (internal and hidden by the external ground plane) but I took a quick look inside a PAL SNES I had around and could only see two 30ohm resistors instead of three. Do you have full schematics of the video circuit?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on July 20, 2008, 03:35:28 AM
Quote from: viletim on July 17, 2008, 02:32:26 PM
Link83,

That diagram is really helpful!
Thanks!  ;D I did one for the Gamecube Scart cable aswell if your interested:-
(http://img175.imageshack.us/img175/8238/gcrgbscartpaintwp7.th.jpg) (http://img175.imageshack.us/my.php?image=gcrgbscartpaintwp7.jpg)
(I have also slightly re-done the SNES one in my previous post)
In case anybody is wondering - the colours I used in the diagrams are based on the colours of the actual wires used in the cable - not always related to what the signals are. Also, they dont show the audio wires as they just connect directly to the scart plug.

Quote from: viletim on July 17, 2008, 02:32:26 PM
Ok, 4*75 ohm resistors, that sounds more like Nintendo... These transistors are "digital", meaning that they have one or more resistors inside. Full part numbers would be DTA124TA and DTC124TF. I've got the datasheet, drawn a circuit. It's actual purpose has me completely befuddled though...
Same here  ??? - they are not used on the Gamecube Scart cable either -  the only similarity is 100ohm resistor present on the +5v line.

if I wanted to re-create the Official PAL SNES scart cable, could I do it on a third-party Gamecube cable by removing the capacitors and putting 75 ohm resistors in there place? - or do the resistors have to be connected to ground/be a resistor network?

Quote from: viletim on July 17, 2008, 02:32:26 PM
I need some active measurements. Plug everything in (cable, nintendo, TV), switch it all on and measure the voltage (with respect to ground) on:
1) the +12v line coming from the SNES (lets see what it really is)
2) pin 8 of the SCART connector
3) pin 16 of the SCART connector

I take it you mean connect it all up with the Scart plugs cover removed and plugged into the TV? (So that I can still make contact with the pins for the readings?) If so I would love to do this but I cant at present as my TV is a 28 inch CRT and I cant get round the back of it very easily in order to connect the probes to the pins :( I have also got a portable CRT TV in the attic though which I will get down as soon as I can and do those tests for you though.

I did do some tests though without the SNES being connected to the TV. My PAL SNES outputs 12.12v on Pin 3 and 5.01v on pin 10 (When using Pin 6&7 for the ground)

Also, when connected to the Scart cable Pin 8 reads +12.14v, and Pin 16 reads 4.99v (With Pin 17 used as ground) I dont know if these readings are of any use to you?

Quote from: viletim on July 17, 2008, 02:32:26 PM
And a couple of passive ones:
Then switch everything off and measure the resistance between pin 8 of the SCART connector and ground (this is actually a measurement of your TV). Now disconnect the cable from everything and measure the resistance between the +12v line coming from the SNES and pin 8 of SCART.
I couldnt do the first of these tests unfortunately, but did try the second one with the cable disconnected from everything. I connected the probes between the +12v line (Pin 3) and Scart Pin 8 and got no reading at all. I tried it on every setting for resistance and there was definitely no measurement (Said '1' on the screen, just like when the probes are not connected to anything)

I even tried measuring resistance on the cable between all of these these points:-
+12v (Pin 3) to Scart Pin 8 - nothing
+12v (Pin 3) to Scart Pin 16 - nothing
+5v (Pin 10) to Scart Pin 8 - nothing
+5v (Pin 10) to Scart Pin 16 - 101 ohms - obviously due to the 100 ohm resistor on the circuit board.

Any other tests you would like me to try without connecting to the TV?

Also I thought it might be good to point out that prior to recieving this Official SNES Scart cable, I had been using an Official Gamecube Scart cable on my SNES with no problems whatsoever. It could just be because my TV is able to handle the signal levels better than other peoples (which often show no picture or fades to black after a few seconds)

Alternatively could it be there is a difference on the video lines of my PAL SNES? It is the very last revision made in 1995, with the code SNSP-CPU-1CHIP-01 printed on the motherboard. Heres some pictures of my SNES which also show the video lines:-
(http://img175.imageshack.us/img175/1381/snes009ty6.th.jpg) (http://img175.imageshack.us/my.php?image=snes009ty6.jpg)(http://img115.imageshack.us/img115/4007/snes005dx2.th.jpg) (http://img115.imageshack.us/my.php?image=snes005dx2.jpg)
(http://img115.imageshack.us/img115/8634/snes012ba2.th.jpg) (http://img115.imageshack.us/my.php?image=snes012ba2.jpg)(http://img115.imageshack.us/img115/9765/snes011pb9.th.jpg) (http://img115.imageshack.us/my.php?image=snes011pb9.jpg)

---------------------------------------------------------------------------------------------------------------------------------------
On a somewhat unrelated note:-

I am curious to know how you are able to measure the voltage of the video lines to make sure they are 0.7vpp? Could I do this with a normal digital multimeter?

Also Viletim, since there never was a PAL Nintendo S-Video cable (I have checked every European eBay site for one) what do you think the components would/should have been on the Chroma and Luma lines? - I have read so much conflicting advice on this. I am guessing there should have been a 75ohm resistor and 220uf capacitor on one of the lines, like the PAL Composite cable, but I still dont know which line this should be to make the signal 'normal'.

Also, I am curious to know why these extra compoents (75ohm resistor and 220uf Capacitor) are even neccessary on PAL Nintendo AV cables? - I had read somewhere that it was due to the 50/60hz difference also affecting the brightness levels - is this true/correct?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 20, 2008, 04:32:23 PM


Ah, the Gamecube too. Can you check if there's a 75 ohm resistor somewhere on the composite line? Measure resistance between ground and each end of coupling capacitor in turn.

No rush on the "in TV" measurements for the SNES SCART cable, whenever you get a chance.

Quoteif I wanted to re-create the Official PAL SNES scart cable, could I do it on a third-party Gamecube cable by removing the capacitors and putting 75 ohm resistors in there place? - or do the resistors have to be connected to ground/be a resistor network?

Nah, they must be in parallel for the same operation.

Regarding the RGB output circuit of the PAL SNES - I've just pulled apart one of mine (1992 model) and had a look at the board. Like MKL said, there's only two 30 ohm resistors there! Something's not right. I'll trace it out again...

Maybe Nintendo revised their video output circuit in later models. You put a cap in series with the video from the 1992 PAL SNES and nothing will come out.

I don't know about the Y/C lines, I'll look into it though... It's very important to get the signal level of composite video/S-video right. It's because you have two parts, the chroma which is frequency modulated (the ammount of colour you get doesn't change with the amplitude of the signal) and luma (contrast is directly proportional to amplitude of the signal). If the luma/composite signal is too big you will get a washed out picture, if it's too small you get oversaturated colours.

The parts in the cables are no less important that the parts in the units. In fact, they would be better off in the units to begin with. I really have no idea why stuffing parts into the SCART cables is so popular...Maybe it makes the unit smaller. :)

BTW - My holidays are over, it may take a few days for me to reply to further questions.

Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 27, 2008, 08:50:15 PM
I examined the internals of my 1992 PAL SNES and can confirm the presence of a 30 ohm resistor in series with red, green, and blue. The circuit looks like: (http://members.optusnet.com.au/eviltim/gamescart/o_snesp.png)
If you put a capacitor in series with the signal it won't work. Nintendo must have changed the circuit somewhere between 1992 and 1995. I presume that their official cable works perfectly with both versions.

I tried to update my website, but I failed. Now there's no diagram for the PAL SNES at all. I've uploaded the new diagram to:
http://morpheus.webcity.com.au/~who49188/gamescart/ (http://morpheus.webcity.com.au/~who49188/gamescart/)
And I suppose I'll have to move the rest of the site over too at some point.

Link83,
QuoteAh, the Gamecube too. Can you check if there's a 75 ohm resistor somewhere on the composite line? Measure resistance between ground and each end of coupling capacitor in turn.
Could you check this? I think I've got an extra resistor in my diagram that shouldn't be there.


Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on July 27, 2008, 09:22:34 PM
Quote from: viletim on July 27, 2008, 08:50:15 PM
I examined the internals of my 1992 PAL SNES and can confirm the presence of a 30 ohm resistor in series with red, green, and blue. The circuit looks like: (http://members.optusnet.com.au/eviltim/gamescart/o_snesp.png)
If you put a capacitor in series with the signal it won't work. Nintendo must have changed the circuit somewhere between 1992 and 1995. I presume that their official cable works perfectly with both versions..

So my 1995 SNES does have different components?

The Official PAL SNES Scart cable works perfectly with my 1995 SNES too, but then so does the Official Gamecube Scart cable! I am hoping to get hold of an earlier revision SNES soon (Hopefully a 1992 version) as this 1995 revision SNES cannot be modified for 50/60hz  :( When I buy it I will test both Official cables with it and update this thread on the results  :)

Also, if your interested I came across this German forum thread about PAL SNES console revisions, which does have some pictures of the different motherboards and may help determine when the 'change' was made (Translated by Google):-
http://translate.google.co.uk/translate?hl=en&sl=de&u=http://www.project-casemod.de/modules/newbb/viewtopic.php%3Ftopic_id%3D835%26forum%3D25%26post_id%3D13143&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3DSNSP-CPU-1CHIP-01%26hl%3Den

I like your new circuit diagram for the PAL SNES Scart cable, but it is still quite different to the Official cable - is this intentional?

Also, now that we know that Nintendo wanted the 'Vpp' to be 0.77 for the PAL SNES, does that mean that 33ohm resistors would be better suited than 47ohm resistors if we wanted to make our own PAL SNES Scart cables? (As the Vpp would then be 0.76 rather than 0.69) [Would also still love to know how you measure 'Vpp']

Sorry about your problems updating your site  :(

---------------------------------------------------------------------------------------------------------------------------------------

Quote from: viletim on July 27, 2008, 08:50:15 PM
Link83,
QuoteAh, the Gamecube too. Can you check if there's a 75 ohm resistor somewhere on the composite line? Measure resistance between ground and each end of coupling capacitor in turn.
Could you check this? I think I've got an extra resistor in my diagram that shouldn't be there.

Sorry I didnt check this before  :-[ - the reason is because shortly after I took the pictures I modified that Official Gamecube cable so that I could use it with my RGB modded N64 by removing all the capacitors off the circuit board (Would have used an unofficial cable but I was desperate to test it right then ::))
I have some new Official Gamecube cables on the way, so I will be testing those for you as soon as they arrive. I am pretty sure however that there was no resistance on the Composite line - only a 220uf capacitor as you can see in the picture. The only resistor in the whole cable is the 100ohm one used on the +5v line.
However, I dont want to give you a 'definite' answer until I have tested the new cables, which are in the post - I hope you understand.

I have been wondering for quite a whiole now - why do so many people recommend putting a 75ohm resistor between Scart pins 18 and 20? There isnt one on the Official cable, as Pin 18 is not even present!

Also, in the official cables both Grounds (Multi AV Out Pins 5 & 6) are joined together and connect to Scart Pin 17, but in your diagrams they connect to many different Scart pins - why is this? Is this just the 'recommended' way a Scart cable should be wired? I am just curious....
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on July 27, 2008, 10:31:50 PM
Quote from: Link83 on July 27, 2008, 09:22:34 PM
Quote from: viletim on July 27, 2008, 08:50:15 PM
I examined the internals of my 1992 PAL SNES and can confirm the presence of a 30 ohm resistor in series with red, green, and blue. The circuit looks like: (http://members.optusnet.com.au/eviltim/gamescart/o_snesp.png)
If you put a capacitor in series with the signal it won't work. Nintendo must have changed the circuit somewhere between 1992 and 1995. I presume that their official cable works perfectly with both versions..

So my 1995 SNES does have different components on the RGB lines?

It's video driver circuit is different, yes. It's normal for bits of the circuit to change through board revisions. It's possible (infact likely) that 47 ohm series resistors (my original PAL SNES diagram) will behave differently with the different internal circuit. The official cable with parallel 75 ohm resistors should work fine with both.
Quote
The Official PAL SNES Scart cable works perfectly with my 1995 SNES too, but then so does the Official Gamecube Scart cable. I am hoping to get hold of an earlier revision SNES soon (Hopefully 1992 version) as this 1995 revision SNES cannot be modified for 50/60hz  :( When I buy it I will test both cables with this earlier SNES and update this thread on the results  :)
I can confirm that 75 ohm parallel resistors on the RGB lines works well for the 1992 model PAL SNES.
Quote
Quote from: viletim on July 27, 2008, 08:50:15 PM
Link83,
QuoteAh, the Gamecube too. Can you check if there's a 75 ohm resistor somewhere on the composite line? Measure resistance between ground and each end of coupling capacitor in turn.
Could you check this? I think I've got an extra resistor in my diagram that shouldn't be there.

Sorry I didnt check this before  :-[ - the reason is because shortly after I took the pictures I modified that Official Gamecube cable so that I could use it with my RGB modded N64 by removing all the capacitors off the circuit board (Would have used an unofficial cable but I was desperate to test it right then)
I have some new official Gamecube cables on the way, so I will be testing those for you as soon as they arrive. I am pretty sure however that there was no resistance on the Composite line - only a 220uf capacitor as you can see in the picture. The only resistor in the whole cable is the 100ohm one used on the +5v line.
However, I didnt want to give you a 'definite' answer until I had tested the new cables which are in the post - hope you understand.
Quote
That's fine, I'm in no hurry.
I have been wondering for quite a whiole now - why do so many people recommend putting a 75 ohm resistor between Scart pins 18 and 20? There isnt one on the Official cable as Pin 18 is not even present!
18 is ground, 20 is video out. This resistor is present on every signle PAL SNES composite cable, and it's inside your SNES SCART cable. If you leave it out you will have a distorted picture. I want to stress that this only applies to the PAL SNES, and maybe the PAL Gamecube (pending your tests).
Quote
Also, in the official cables both Grounds (Multi AV Out Pins 6 & 7) are joined together and connect to Scart Pin 17, but in your diagrams they connect to many different Scart pins - why is this? Is this just the 'recommended' way a Scart cable should be wired? I am just curious....

I'm not really interested in documenting every paltry detail of the various SCART cables. I don't care how the ground is wired, so long as it is wired. I draw all the diagrams with one ground connected at the the console end and all grounds connected at the SCART end. The reverse is probably more like the way they are actually wired, but I draw it this way because: 1. Connecting all the grounds together at the console end makes the diagram look messy 2. It highlights the fact that a SCART socket has multiple ground connections, there is no "best one".

Also, I always use a 180 ohm resistor between +5v (if it exists) and the RGB status pin 16. For no better reason than I like it like that. Any resistor from 100 to 200 ohms would also be suitable, though.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on August 10, 2008, 06:02:30 AM
Here is the SHVC-010 PCB underside:
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on August 10, 2008, 06:03:40 AM
And here are angled pictures of the top side
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on August 27, 2008, 11:19:45 PM
Quote from: viletim on July 27, 2008, 10:31:50 PM
Ah, the Gamecube too. Can you check if there's a 75 ohm resistor somewhere on the composite line? Measure resistance between ground and each end of coupling capacitor in turn

Could you check this? I think I've got an extra resistor in my diagram that shouldn't be there.
I am so sorry for taking so long to get back to you on this - my new Official Gamecube Scart Cables just arrived a week ago (Took alot longer to arrive than I thought they would)

Anyway, having tested a totally unmodified cable I can confirm that there is indeed a 75ohm resistor between Composite and Ground on the Official Gamecube Scart cable. I was very surprised at this, as it isnt on the little PCB. Also, I didnt notice it before in my previous 'testing' because I was connecting the probes after the Capacitors, not before them, Doh! ::)

Having taken apart the MultiAV plug end though I can see that the resistor is there, covered in heat shink tubing. Its also covered up by a piece of black sticky fabric - so its abit hard to see normally. Heres some pics with the fabric peeled away, making the resistor alot more obvious:-
(http://img517.imageshack.us/img517/3213/av004ad2.th.jpg) (http://img517.imageshack.us/my.php?image=av004ad2.jpg)(http://img517.imageshack.us/img517/3769/av006jg9.th.jpg) (http://img517.imageshack.us/my.php?image=av006jg9.jpg)

Funny thing is though that the Official Gamecube Scart Cable doesnt use Pin 18 for Ground - it uses Pin 17 for Ground instead! Isnt that incorrect for the 'proper way' or wiring a Scart cable? Ground is the Grey wire in this pic:-
(http://img170.imageshack.us/img170/6220/gcrgbscart032px5.th.jpg) (http://img170.imageshack.us/my.php?image=gcrgbscart032px5.jpg)

So the Composite line has a 75ohm resistor connected to ground, and a 220uf capacitor on it, just like the Official PAL AV Cables.

RGB32E - Just wanted to say a big thank you for those pictures  ;D They are really interesting - its kind of strange how 'basic' looking the PCB is on the SVHC-010 compared to Nintendo's European Scart cables.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: viletim on August 28, 2008, 01:42:47 AM
Quote from: Link83 on August 27, 2008, 11:19:45 PM

Anyway, having tested a totally unmodified cable I can confirm that there is indeed a 75ohm resistor between Composite and Ground on the Official Gamecube Scart cable. I was very surprised at this, as it isnt on the little PCB. Also, I didnt notice it before in my previous 'testing' because I was connecting the probes after the Capacitors, not before them, Doh! ::)
Thanks for the confirmation. It seems my diagram is correct after all.

Quote


Funny thing is though that the Official Gamecube Scart Cable doesnt use Pin 18 for Ground - it uses Pin 17 for Ground instead! Isnt that incorrect for the 'proper way' or wiring a Scart cable? Ground is the Grey wire in this pic:-

It doesn't matter, both pins are connected to ground in all TVs.

Quote
So the Composite line has a 75ohm resistor connected to ground, and a 220uf capacitor on it, just like the Official PAL AV Cables.
At least they're consistant...
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on August 28, 2008, 01:48:27 AM
Here are more...
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on September 18, 2008, 09:46:49 AM
Quote from: RGB32E on August 28, 2008, 01:48:27 AM
Here are more...

Thanks for the extra pictures RGB32E, you have saved me from buying an SVHC-10 cable purely for curiosities sake!  ;D

---------------------------------------------------------------------------------------------------------------------------------

In the past few days I thought id have a look at a PAL N64 motherboard to see what differs between the S-Video lines on a PAL and NTSC board, and there are some surprising differences (Well surprising to me anyway)

Basically it looks like Nintendo decided to remove some components on the video lines on the PAL N64 - I can only assume they did this to act as some form of 'region locking' on accessories like they did with the PAL NES and SNES controllers.

Heres some pictures I have taken showing the differences on the AV lines, I have traced out the Composite, Chromo and Luma lines onto the pictures. Please excuse any extra wires you may see  :)
NTSC
(http://img292.imageshack.us/img292/3955/ntscfrontpaintmt5.th.jpg) (http://img292.imageshack.us/my.php?image=ntscfrontpaintmt5.jpg)(http://img292.imageshack.us/img292/5412/ntscbackpaintvw5.th.jpg) (http://img292.imageshack.us/my.php?image=ntscbackpaintvw5.jpg)

PAL
(http://img292.imageshack.us/img292/5326/palfrontpaintcd4.th.jpg) (http://img292.imageshack.us/my.php?image=palfrontpaintcd4.jpg)(http://img292.imageshack.us/img292/7465/palbackpaintij4.th.jpg) (http://img292.imageshack.us/my.php?image=palbackpaintij4.jpg)
Close up of the rear of the PAL boards DENC-NUS chip:-
(http://img233.imageshack.us/img233/5400/dencclosepaintuz9.th.jpg) (http://img233.imageshack.us/my.php?image=dencclosepaintuz9.jpg)

Colour Guide:-
Composite - Yellow
Luma - Cyan/Blue
Chroma - Purple
Ground - Brown/Orange

There are six main components that I can see missing.

Two are for the Composite line labelled R5 and JP4. R5 should be a 75ohm resistor to Ground, and JP4 should be a 220uf 10A Capacitor. Instead Nintendo added these two components inside the PAL Composite AV cable instead ::)

The other four components should be for the S-Video Chroma and Luma lines. The problem here is Nintendo in their infinite wisdom not only removed some crucial components for S-Video, but then also never released a PAL N64 S-Video cable, meaning most PAL owners never even got an decent S-Video picture from an N64  :(

The four components are labelled R6, R7, JP5 and JP6. Heres what I think they should be
R6 = 75ohm Resistor to ground
R7 = 75ohm Resistor to ground
JP5 = 220uf 10A Capacitor
JP6 = Capacitor - not sure of the value.

Heres the problem - im not sure what value capacitor JP6 should be. Im guessing it should be the same as the capacitor at location C14 on the NTSC board, but unfortunately I dont have a Capacitor meter so cant measure the value - can anybody help?

Also, would it be possible to add the missing components externally to a Nintendo S-Video cable? Im guessing whats needed is a 75ohm resistor to ground on the Y and C lines, and then a capacitor on each line aswell. Would the ordering of these resistors/capacitors be important at all?

Im also curious as to why Nintendo used large 220uf 10A Capacitors on the Luma and Composite lines - why didnt they just use the 'normal' 220uf 6.3v Capacitors they used in the Official Scart and Composite cables? or why didnt they just use small surface mounted Capacitors instead?

Any advice would be much appreciated  :)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: Holering on September 23, 2008, 04:28:36 PM
Could anyone tell me how to open a third party snes plug (the male end that goes into the console itself). This cheapo RGB cable I got from ebay has no visible tabs and just two tiny holes on the top and bottom of the casing. I really wanna open this thing and check out how the grounds are wired up. The video noise going into the sound is terrible and I'm really curious as to why it's there compared to the standard AV cable which has no noise whatsoever. At first I thought it was a ground loop but there is just no way after all the testings I've done. I'm convinced it's either a missing ground or I just need to take the audio wires off the scart end of the cable and use them on some standard phono jacks to hopefully see any improvement (after reading some threads here it seems that cheap rgb cables probly introduce horrible buzz-fuzz noise into the sound)

Also is there any such wiring that's easily available-low cost that is shielded to prevent any EMI or other interferences. I'm talking about wire that's small enough to rebuild an RGB+SOUND scart lead. Wouldn't shielded wire prevent this noise from being introduced into the sound?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: NFG on September 23, 2008, 04:41:18 PM
QuoteCould anyone tell me how to open a third party snes plug (the male end that goes into the console itself).
Many of the cheap ones are glued together.  The key is usually in the seams...  If you can't pry them apart, they're probably glued...  The holes may not be relevent, what do you see when you shine a light down 'em?

If they are glued, you'll either have to pry 'em apart with a screwdriver, or cut 'em with a very sharp knife.  Make lots of small cuts, rather than trying to force through it in one go.  Fewer chances for error.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on September 23, 2008, 10:48:27 PM
Quote from: Holering on September 23, 2008, 04:28:36 PM
Also is there any such wiring that's easily available-low cost that is shielded to prevent any EMI or other interferences. I'm talking about wire that's small enough to rebuild an RGB+SOUND scart lead. Wouldn't shielded wire prevent this noise from being introduced into the sound?
I think I have had the exact same RGB cable (cheap one available from Play Asia) There is no shielding in it at all and I am positive thats the cause of the interference. On mine I even had interference in the video signal aswell :(
The official cable doesnt introduce any noise and is shielded - though thats probably not what you wanted to hear - sorry!
-----------------------------------------------------------------------------------------------------------------------------------------

Just thought id also add that thanks to Viletim in another thread I now know that C14 on an NTSC board is a 68nf capacitor, so:-

R6 = 75ohm Resistor to ground
R7 = 75ohm Resistor to ground
JP5 = 220uf 10A Capacitor
JP6 = 68nf Capacitor

Im guessing if Nintendo had released a PAL N64 S-Video cable it would have contained all of these components.

The only thing im unsure about is if the component ordering is important - eg should the 75ohm resistor be first on each line, or the capacitors?  ???

Now if I am to follow the motherboard ordering the 75ohm resistors to ground would be first, followed by the capacitors.

But when I looked at the Official PAL Composite/AV cables the capacitor appears to be first, followed by the 75ohm resistor to ground.

So im beginning to think the component ordering is unimportant?

Also, can I add the missing components externally into the cable? Or would they have to be added to the N64 motherboard (I imagine I can add them to the cable but just want to be sure)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: MKL on September 24, 2008, 12:23:00 PM
Quote from: Holering on September 23, 2008, 04:28:36 PM
Could anyone tell me how to open a third party snes plug (the male end that goes into the console itself). This cheapo RGB cable I got from ebay has no visible tabs and just two tiny holes on the top and bottom of the casing. I really wanna open this thing and check out how the grounds are wired up.

I wrap a cloth around the plug and hit it *lightly* with a hammer on one of the sides: quick, effective and doesn't leave marks on the hood:

(http://img89.imageshack.us/img89/7008/snesplug2nv7.th.jpg) (http://img89.imageshack.us/my.php?image=snesplug2nv7.jpg)

The wiring is indeed of a very low quality: the wires are too thin (28AWG), poorly insulated and soldered and the cable is unshielded:

(http://img526.imageshack.us/img526/9208/snesplug1yh7.th.jpg) (http://img526.imageshack.us/my.php?image=snesplug1yh7.jpg)

Quote from: Holering on September 23, 2008, 04:28:36 PM
Also is there any such wiring that's easily available-low cost that is shielded to prevent any EMI or other interferences. I'm talking about wire that's small enough to rebuild an RGB+SOUND scart lead. Wouldn't shielded wire prevent this noise from being introduced into the sound?

I replaced the cable with a shielded 8x0.25mm (8 cores, 24AWG each) one:

http://www.tasker.it/prodotti/prodotti_scheda.php?idcat=11&cod=C8025&idcod=269

(http://img385.imageshack.us/img385/7274/59363999xp0.th.jpg) (http://img385.imageshack.us/my.php?image=59363999xp0.jpg)

Next to the stock cable:

(http://img87.imageshack.us/img87/7524/30179182xk2.th.jpg) (http://img87.imageshack.us/my.php?image=30179182xk2.jpg)

Since there are two ground pins on the connector I used one for the shielding and the other for one of the wires. Perhaps I'll post a short guide on how to make a snes cable detailing all the steps (replacing the strain relief grommet, etc.).
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: Holering on September 24, 2008, 12:56:45 PM
Did this get rid of the buzz-fuzz noise in the sound or at least improve it? What about diagnol scanlines? Did it get rid of that? These weren't visible with an svideo lead...
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: MKL on September 24, 2008, 09:11:52 PM
I didn't even test it since it was for gamecube and wouldn't work with a SNES. I modded it straight away and all I can say is that it works perfectly, no audio interference at all. The little A/V box in the middle of the cable could also be responsible for degrading the audio signals.
One thing you could do if all else fails and you feel like doing a bit of work is fitting stereo jacks on the SNES case and run audio and video on separate cables (after disabling audio on the scart cable) and see if it gets better. If it does then you can be sure about the crappy chinese cable being the responsible for the audio issue.

(http://img367.imageshack.us/img367/8908/19962017lj8.th.jpg) (http://img367.imageshack.us/my.php?image=19962017lj8.jpg)
(http://img367.imageshack.us/img367/3416/jjxg7.th.jpg) (http://img367.imageshack.us/my.php?image=jjxg7.jpg)
(http://img367.imageshack.us/img367/4966/20935882oo6.th.jpg) (http://img367.imageshack.us/my.php?image=20935882oo6.jpg)

Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacit
Post by: Holering on September 25, 2008, 07:03:24 AM
Cool that looks nice and neat! I'll probly start modding all my bastard systems and keep the non-modded-boxed systems stored away since those have all the books and what not...

Also could I rebuild my rgb-scart leads with 24AWG shielded speaker wire? Isn't it the same? I don't think RGB+sound needs a certain cable with specific ohm ratings does it (component-yuv cable comes to mind...)?This seems easily available where I'm located and cheap too.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on January 16, 2009, 04:34:40 AM
I realise this thread is quite an old thread now, but I have some relevent info that i'd like to update it with  :)
I was reading what phreak97 said here:-
http://nfggames.com/forum2/index.php?topic=3510

...and I started wondering, what was really inside an Official Nintendo PAL SNES and PAL N64 AV/Composite Cable - were they really different to the PAL Gamecube Composite cable?

After a few hours rumaging around I managed to find my two boxed PAL cables for SNES and N64 (The Composite AV cables were sold separately here in the UK, as we only got RF cables supplied in the box with the SNES and N64 :'()
Firstly the PAL SNES AV cable.
Heres the box:-
(http://img90.imageshack.us/img90/4575/palsnescomposite34ba7.th.jpg) (http://img90.imageshack.us/my.php?image=palsnescomposite34ba7.jpg)(http://img387.imageshack.us/img387/3038/palsnescomposite12wg0.th.jpg) (http://img387.imageshack.us/my.php?image=palsnescomposite12wg0.jpg)

Inside the plug:-
(http://img387.imageshack.us/img387/6365/palsnescompositemx7.th.jpg) (http://img387.imageshack.us/my.php?image=palsnescompositemx7.jpg)(http://img387.imageshack.us/img387/3167/palsnescomposite3mb3.th.jpg) (http://img387.imageshack.us/my.php?image=palsnescomposite3mb3.jpg)(http://img387.imageshack.us/img387/2951/palsnescomposite5tg7.th.jpg) (http://img387.imageshack.us/my.php?image=palsnescomposite5tg7.jpg)

As you can see it only has a 75ohm resistor to ground (which I have to say looks to me pretty poorly done - I mean it goes all over the place - and wheres the insulation?!) So it is different to the PAL Gamecube Composite cable as that had a little circuit board with a 220uF capacitor in series aswell as the 75ohm resistor to ground (See first page of this thread for pics)

Next I opened up an Official PAL N64 Composite cable. The box says its suitable for both the SNES and N64 so I was still expecting to see the 75ohm resistor to ground, but I also thought there would be a 220uF capacitor aswell - as these are the two components missing off the PAL N64 motherboard's Composite line (Please see my post further up for comparison pics)
Heres the box:-
(http://img387.imageshack.us/img387/2397/paln64composite015je8.th.jpg) (http://img387.imageshack.us/my.php?image=paln64composite015je8.jpg)(http://img387.imageshack.us/img387/8867/paln64composite016ds6.th.jpg) (http://img387.imageshack.us/my.php?image=paln64composite016ds6.jpg)

Inside the plug (Plug is the opposite side up to the SNES pictures as otherwise you couldnt see the resistor):-
(http://img387.imageshack.us/img387/7153/paln64compositevf3.th.jpg) (http://img387.imageshack.us/my.php?image=paln64compositevf3.jpg)(http://img387.imageshack.us/img387/2092/paln64composite1tq3.th.jpg) (http://img387.imageshack.us/my.php?image=paln64composite1tq3.jpg)(http://img387.imageshack.us/img387/3379/paln64composite3kl1.th.jpg) (http://img387.imageshack.us/my.php?image=paln64composite3kl1.jpg)

I was surprised to see that its pretty much identical to the PAL SNES cable - except that they have now secured and insulated the resistor by wrapping a clear piece of plastic insulation round the resistor and the composite wire.

Whats got me really puzzled is why they havent used a 220uF capacitor aswell? We already know its missing from the PAL motherboard and I very much doubt PAL Composite signal levels should be different to the NTSC Composite signal levels?

I'm guessing the missing capacitor is meant to remove the 'DC offset' like the NTSC SNES RGB cables capacitors, but why then would Nintendo leave it out?  ??? The space on the motherboard suggest the PAL N64 needed it to some extent.

I have also updated the Nintendo MultiAV PAL/NTSC Chart here:-:-
http://gamesx.com/wiki/doku.php?id=av:nintendomultiav
Hopefully you can see its more detailed now :)

...Nintendo really like messing with their PAL consoles and video cables - im so glad the Wii has done away with all this 'components in cables' nonsense....
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: phreak97 on January 16, 2009, 11:54:06 AM
maybe theyre expecting your tv to have a cap on the line? are there different composite video tolerances for pal regions?

this could possibly explain why my snes never worked with my tv capture card.. it always displayed all garbled.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on January 17, 2009, 03:02:32 AM
Quote from: phreak97 on January 16, 2009, 11:54:06 AM
maybe theyre expecting your tv to have a cap on the line?
I thought that, but then surely there would be no need to add the capacitor in the Gamecube AV cable?

Quote from: phreak97 on January 16, 2009, 11:54:06 AM
this could possibly explain why my snes never worked with my tv capture card.. it always displayed all garbled.
Possibly! Maybe give it a try if you have a Gamecube Composite cable handy? Alternatively maybe your TV capture card doesnt support PAL Composite?

------------------------------------------------------------------------------------------------------------------------------------

I found a little bit of information which is quite interesting. I was looking though the support section of the Nintendo Europe website (The support section used to comprise of simply an email address, postal address and phone number - but since the site 'revamp' last year it now has FAQ sections aswell) I wasnt expecting the person writing them to have been that knowledgable on differences between cables, but it appears they did know there was a difference. These are the interesting bits:-

http://www.nintendo.co.uk/NOE/en_GB/support/nintendo_gamecube_162_168.html
Quote from: Nintendo Europe
Stereo AV Cable and Scart Adapter
...
NOTES:
The Nintendo GameCube stereo AV cable is downwardly compatible with the Nintendo 64 and the Super Nintendo.
With the Nintendo GameCube, only the Nintendo GameCube stereo AV cable or other products licensed by Nintendo must be used.
Do not connect a stereo AV cable to the Nintendo GameCube that is intended for the Super Nintendo or the Nintendo 64.

http://www.nintendo.co.uk/NOE/en_GB/support/nintendo_gamecube_162_205.html
Quote from: Nintendo Europe
Game has a white tint
The image problem occurs in all games:
Check whether the Nintendo GameCube was connected to the TV with a Super Nintendo or Nintendo 64 stereo A/V cable (can be seen from the dark grey multi-out plug) - the original Nintendo GameCube stereo A/V cable has a black multi-out plug).
Connect your Nintendo GameCube - if possible - to another TV to exclude a defect on the TV.
If possible, test the Nintendo GameCube with another original Nintendo GameCube stereo A/V cable (recognised by the black multi-out plug)....

Seems like the Gamecube Composite cable should work fine with all three consoles, whilst the SNES and N64 cables cannot be used with the Gamecube as it produces a 'white tint'.

I think its safe to say that there should be no problems adding the 220uf capacitor for the PAL N64 - it seems it was originally intended (based on the motherboard spaces) and 'straight from Nintendo' we know the PAL Gamecube Composite cable works fine with the PAL N64. The only reason I think as to why Nintendo left out the capacitor is to save money if they could get away without it - I certainly think you should use one if you can - if it makes any difference to the picture quality or not I cant say as yet.

Id be intrigued to know if the PAL SNES should have used the capacitor or not - there isnt a 'space' on the motherboard though like the PAL N64 so its hard to say.

When I have time I think I will try comparing each cable on each console and note any visual diifferences, aswell as seeing if I can measure the 'DC offset' produced from each cable.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: phreak97 on January 17, 2009, 11:27:32 AM
maybe the pal snes and n64 remove the dc offset somewhere earlier in the process? obviously my theory of the tv doing the work is wrong if other consoles are still affected.

it isnt entirely true that the gamecube cable is backwards compatable.. some games have a messed up image when using the gamecube cable with my setup. super mario world is one.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on January 23, 2009, 01:44:31 PM
I just wanted to update that I tested both a PAL SNES/N64 Composite cable and a PAL Gamecube Composite cable on a PAL N64 console.

Visually I couldnt see any difference using either cable (but maybe im not looking hard enough)

I then decided to measure the DC offset from the PAL N64. Using the PAL Gamecube Composite cable (75ohm resistor to ground and 220uF capacitor in series) it measured 0.00V as I expected.

Next I tried the PAL SNES/N64 Composite cable (75ohm resistor to ground) and somewhat surprisingly got readings betweens 0.7V and 1.35V DC - varying according to how bright the game picture was. During gameplay it seemed to average out at about 1V DC.

I am not sure what effect this DC offset would have on the picture quality, but I dont think it would be for the better. I have read in many audiophile forums that having a DC offset on headphone amplifiers higher than 20mV (0.02V!) can have a detrimental affect on the sound and can damage the speakers :o, so I assume a 1V DC offset on Composite video would be the same/similar(?)

All this suggests that to me their definitely should be a 220uF capacitor in series on the PAL N64 Composite line aswell as the 75ohm resistor to ground, and that Nintendo just cheaped out on making the PAL N64 Composite cable because they could get away with it ::)

I havent been able to test the PAL SNES yet as I have just accidentally blown the fuse on my console :( (Even though I 'discharged' it for 10 seconds first) but when I get a new fuse I will compare the PAL SNES aswell and update this thread.

Sorry if anyone finds this info boring - I realise it wont interest many as its only Composite Video!
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Cainam on March 14, 2009, 11:53:52 PM
Well, I for one am interested anyway! Actually, I am more interested in the s-video side of things, but I think the same logic applies to both.

Out of interest, and not understanding much about electronics, why a resistor to ground on the video line? Wouldn't a resitor in series work just as well?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Piratero on May 25, 2009, 06:19:52 AM
Quote from: viletim on August 28, 2008, 01:42:47 AM
Quote from: Link83 on August 27, 2008, 11:19:45 PM

Anyway, having tested a totally unmodified cable I can confirm that there is indeed a 75ohm resistor between Composite and Ground on the Official Gamecube Scart cable. I was very surprised at this, as it isnt on the little PCB. Also, I didnt notice it before in my previous 'testing' because I was connecting the probes after the Capacitors, not before them, Doh! ::)
Thanks for the confirmation. It seems my diagram is correct after all.

Quote


Funny thing is though that the Official Gamecube Scart Cable doesnt use Pin 18 for Ground - it uses Pin 17 for Ground instead! Isnt that incorrect for the 'proper way' or wiring a Scart cable? Ground is the Grey wire in this pic:-

It doesn't matter, both pins are connected to ground in all TVs.

Quote
So the Composite line has a 75ohm resistor connected to ground, and a 220uf capacitor on it, just like the Official PAL AV Cables.
At least they're consistant...

Sorry for the bump. But connecting pin 17 to GND is essential. I just built an RGB cable using the official GameCube PAL SCART cable. In other words, it does matter!
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: zedrein on May 25, 2009, 01:45:35 PM
Oh sweet, so there is a RGB scart cable that will work with NTSC Super NES systems with the composite sync actually brought out? I'd love to get one of these so I don't have to build a sync-separator.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on May 25, 2009, 11:58:47 PM
Wow, this thread will never die!  :)
Quote from: Piratero
Sorry for the bump. But connecting pin 17 to GND is essential. I just built an RGB cable using the official GameCube PAL SCART cable. In other words, it does matter!
I know your agreeing with me and all, but I think what Viletim was saying is that it is still essential to connect the ground pin, but with a Scart connection it doesnt matter if you use Pin 17 or Pin 18 as they are both connected to ground internally inside a Scart enabled TV. Since you say you built an RGB cable out of a PAL GameCube Scart cable im guessing you are not using a Scart connection anymore so will need to connect the ground wire to whichever pin your monitor uses for ground.
The ground wire must always be connected at both ends of the cable to the grounds of the console and TV/Monitor

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Quote from: zedrein on May 25, 2009, 01:45:35 PM
Oh sweet, so there is a RGB scart cable that will work with NTSC Super NES systems with the composite sync actually brought out? I'd love to get one of these so I don't have to build a sync-separator.
I have never found a manufactured Nintendo cable that has Composite Sync already connected, so im not sure what you mean ??? If you require C-Sync you would need to build/alter a cable yourself. Also, if your TV/Monitor requires separate H & V Sync's you will still need to use a sync-separator circuit.

I think you may be getting mixed up between Composite Video and Composite Sync?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: RGB32E on May 26, 2009, 02:26:28 AM
Quote from: Link83 on May 25, 2009, 11:58:47 PM
I have never found a manufactured Nintendo cable that has Composite Sync already connected, so im not sure what you mean ??? If you require C-Sync you would need to build/alter a cable yourself. Also, if your TV/Monitor requires separate H & V Sync's you will still need to use a sync-separator circuit.

I think you may be getting mixed up between Composite Video and Composite Sync?

Like I've stated before, the Official GameCube SCART cable does have pin 4 wired to the SCART connector.  However, it's purpose is to carry +12VDC.  When used on a NTSC SNES/SFC, what is carried over that wire is composite sync instead!  I cannot say if there were different Official GameCube SCART cables, but the one I have is already wired with pin 4...  :-\
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: zedrein on May 26, 2009, 08:04:05 AM
^That's great. Can you link me up to that specific cable you are talking about? Do you have to put a cap or something in the C. sync line?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Link83 on May 26, 2009, 11:59:04 AM
Quote from: RGB32E on May 26, 2009, 02:26:28 AM
Like I've stated before, the Official GameCube SCART cable does have pin 4 wired to the SCART connector.  However, it's purpose is to carry +12VDC.  When used on a NTSC SNES/SFC, what is carried over that wire is composite sync instead!  I cannot say if there were different Official GameCube SCART cables, but the one I have is already wired with pin 4...  :-\
Doh! Thanks for pointing that out.  I actually already knew that yet it totally slipped my mind when I made that post, sorry  :-[ Its the only pin thats different on the MultiAV port between NTSC and PAL regions. However, Scart pin 8 is not meant to be carrying a C-Sync signal, so at least I was half right  ;) as you will still need to build/alter the cable yourself in order to make use of the C-Sync signal (or make a specific adaptor to suit your needs/TV/Monitor)

...and zedrein, its an Official GameCube RGB Scart cable, you can only really find it on European eBay's now though. Theres a few new ones on eBay Germany:-
http://cgi.ebay.de/N64-SNES-GameCube-RGB-Scart-Kabel-Original-Nintendo-NEU_W0QQitemZ300316564233
(I dont know the seller, or even if they will ship outside of Germany)

The official cable has a little circuit inside it (Picture can be seen on first page) that could make it quite difficult to fit it inside your own custom connector. It might be easier/cheaper for you to buy two official Composite AV cables and then open the connectors and use the pins from both plugs to make a MultiAv port with up to 8 pins? Then you could use whatever cable you want, and add whatever components you need.

I have read mixed opinions on if you need a Capacitor and/or Resistor on the C-Sync line of the SNES so I really cant say for sure whats needed, expecially since no Official Nintendo cables were ever designed/meant to use the C-Sync signal so theres nothing we can compare to.

As you may already know, beware of unofficial Nintendo scart cables as they are usually missing the C-Sync/+12V wire entirely and rely on the +5V wire only for both scart switching signals, using a resistor between Pin 8 and 16 (This leads to a default Widescreen ratio selection on most Scart enabled TV's) I assume they do this to ensure scart switching compatibility with both PAL and NTSC consoles, but it also makes the cables useless for your needs (The C-Sync signal)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 03, 2010, 12:23:29 AM
Waise from your Gwaive!

Hey, while doing some casual searching for the source of a RGB problem of mine I fell upon this thread and some of you seem pretty knowledgeable. So I thought I'd resurrect this thread for your input on this.

Here is my setup, I have NTSC SNES, I bought it new and thus the chance of it being faulty is pretty low. The words "EJECT" are molded on its eject button instead of being printed which according to this (http://kyorune.com/modding/article.php?id=13) site means that my SNES is of a newer revision with a smaller motherboard and some cost cutting. It is not one of those small SNES's mind you, it is the big old ugly NTSC one, just with a never revision internals.

I bought the official SHVC-010 RGB21 cables to connect it to a XRGB unit. This is a neat piece of hardware from Japan that takes 240p video from older consoles and scandoubles them to 640x480 VGA. This way you can connect your old consoles to a PC monitor, or even a HDTV if you so please.

What is neat about it is that it has a RGB SCART input built into the machine, but it is wired for Japanese RGB21 SCARTs obviously. Also it can make the scandoubled lines be fake scanlines so games look like they did on older CRT TV's.

I believe it is an analogue device, so no conversion to digital is taking place, so there is no lag, and what you get in is what you get out, only with double the vertical frequency.

Now, plugging your SNES into this via RGB21 SCART and plugging the VGA output into your CRT monitor should work, but here a problem.

I get an absolutely horrid picture by doing this, there is something very wrong.

It seems there is some internal difference between Super Famicom and the NTSC SNES, specifically the newer revision one that I got, which makes for disaster.

I should mention the cables I got are new, so no chance of them being broken, nor is there anything wrong with the XRGB-2 Plus unit that I have. It works great with my SEGA CDX.

As you can imagine those cables did not come cheap, so I am now wondering why they do not work. Would appreciate some expert input, because I am pretty much clueless.

Here are some shots of the problem on a CRT monitor as compared to reference quality emulation on a LCD:

Actual hardware on CRT monitor 1 (http://gallery.me.com/kamiboy#100037/IMG_0627)
Emulator 1 (http://gallery.me.com/kamiboy#100037/IMG_0631)

Actual hardware on CRT monitor 2 (http://gallery.me.com/kamiboy#100037/IMG_0625)
Emulator 2 (http://gallery.me.com/kamiboy#100037/IMG_0626)

To describe the image problem in more detail. Other than shadows and colours that are completely wrong. I have a very dark image, requiring me to crank everything up to max to even get a visible picture, and then it seems like each primary colour is being displayed out of sync with the other colours. So RED looks like it is being displayed a few pixels to the right etc. Creating a outline beside everything.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 03, 2010, 12:05:04 PM
I also have a SHVC-010 RGB21 cables to connect to a US NTSC (purple breeze block) to a LCD sony Bravia 3via  XRGB  2 plus unit, no problems at all, I am not sure why you have problems, have you tried via vga slot on a modern lcd/plasma tv to see if the problem is from your console/upscanner or the actual tv
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 03, 2010, 12:09:18 PM
i also tried a xrgb 2 (non plus) and an older xrgb1, (every so often i sell these items)  same again, no problems with this cable using US ntsc snes even with super famicom cartridges.

Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 03, 2010, 10:50:51 PM
Hmm..., that is certainly strange. Could I ask wither your SNES's have the words "EJECT" molded upon the button or is it printed on? I have  a suspicion that my problems are related to SNES internal revision and that is an indicator of wither one has a newer or older revision.

I did try this on my LCD TV as well, but things look even worse there. In fact my LCD does not work very well with the XRGB at all. The CDX and Saturn which are systems that give me the best and most stable image exhibit a very bad shaking problem on my LCD. This is because my LCD has a very bad VGA input, as such I don't use it for playing classic systems.

My CRT monitor on the other hand has a beautiful picture when connecting to the XRGB. The only system to give me problems with it has been my SNES via RGB. In a few weeks I'll be getting some S-video cables for the SNES as well which I imagine will solve all of my problems, still I would like to know why the SNES did not work.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 04, 2010, 12:27:31 PM
i will need to check my purple snes for what ver,  is your cdx plugged via rgb? surely buying a new snes is cheaper or the as the cost of snes/n64/gc s video

btw what lcd brand do you have?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 04, 2010, 09:47:56 PM
Yes my CDX is plugged in via RGB, bought the cables off of a UK guy that makes them himself. My LCD brand is a Sharp 52XS1, sort of a rare television, made in limited quantities and retailed for an insane amount originally.

I originally bought the XRGB to be able to enjoy older games via RGB on it with scanline emulation. But the VGA input gives me a very unstable picture so I will not be playing games that way. Fortunately I rescued a 22" CRT from my work as it was about to be thrown out in batch.

Seeing how good games can look on CRT made my LCD problems a none issue. The cost of a new SNES was a lot, and I have already purchased S-video cables. But I paid a lot for those Japanese SCART RGB cables and I am curious why things didn't work out.

I saw that there has been a lot of talk about resistors and capasitors and internal SNES and SNES cable build and thought people could shine some light on the mystery.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 05, 2010, 12:39:16 PM
but i was under the impression that s video or even worse composite via xrgb  is defeating the point, but with your distorted images, better than nothing, cos i hve a not so good brand tv previously,I was very picky on my current tv as i have checked these forums for the most compatible.

I assume your ntsc snes maybe the problem, but i am not sure, maybe i was just lucky when i brought my one second hand as i have no idea on the revisions/version of snes.

I am currently having minor issues with my rgb modded pc engine (without rgb amp), i can control the colours with my xrgb, but the contrast/brightness is a slight issue, ie, too high, slightly distorted/bleeding, while too low it becomes too dark .
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 05, 2010, 09:08:52 PM
Quote from: imparanoic on November 05, 2010, 12:39:16 PMas i have no idea on the revisions/version of snes.

That is easy, does your SNES EJECT button look like this, with the words "EJECt" printed on:

(http://kyorune.com/modding/file.php?art=13&file=1)

Or This, with the words molded on:

(http://kyorune.com/modding/file.php?art=13&file=2)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 05, 2010, 09:39:48 PM
sorry, dodgy english, i meant, I did not know about the difference until come across this forum, i am familar with revised ver of pc engine, ps1, ps2 etc, but not snes
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 05, 2010, 10:37:39 PM
i like to tell you quickly which ver of snes, but i am in the middle of moving, thus, not sure when i check up on the ver of snes for a few days.

yes, i am aware that native j rgb leads are pricey, but as i am based in hk, every so often i will come across one same with the xrgb's, i paid 11gbp for snes  j rgb lead ( no demand in hk) and my japanese friend help me get a scph-1050 j rgb for ps1/ps2.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 06, 2010, 01:45:58 AM
I see. Well as for your remarks regarding using XRGB via S-video and composite being pointless, then that depends on what you want to use it for.

For some the XRGB is the only way to make use of the best connection method of their console, RGB. But for me I just want the XRGB for the Scanline emulation. I am using it with a CRT monitor so S-video and even composite actually perform very, very well. Switching between RGB and S-video on my Saturn I cannot see any difference between them. And of course RGB does not even work properly on the SNES so my only option there is S-video.

And of course, some systems only have composite, like the NES. But all the systems that I have working, via RGB, S-video or even component look great on my CRT monitor. With scanlines turned on it looks just like on an old TV.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 07, 2010, 01:13:46 AM
newer ver snes
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 08, 2010, 11:47:19 PM
Well then that would have ordinarily settled it, but then I went ahead and opened up my SNES to have a gander inside and it turns out, out of the two different revisions of the newer SNES's I have the very last, which is apparently very rare in NTSC. What gives away the difference between the two newer SNES's which both have the molded button is wither the sound hardware is in one or two chips. The normal newer SNES's have a two chip sound solution but mine has just the one. Nintendo prolly removed or added some caps from the RGB signal path while doing this last NTSC revision which made the signal incompatible with the SHVC-010 cables.

I don't have the knowhow or equipment to figure out what the problem is exactly, so I'll settle for S-video, it prolly looks almost as good anyway.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: imparanoic on November 09, 2010, 12:45:22 PM
but surely if you willing spend SHVC-010 cables cost at -around 45 to 55gbp, a second hand us ntsc snes will cost around 10 gbp?, is that worth the cost?, especially considering the xrgb alone would cost around 80gbp for xrgb2, 100 for xrgb 2 plus and 150 for second hand xrgb3

Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 12, 2010, 02:41:40 AM
I ended u paying closer to 180 gbp for my XRGB2+, and the threes come quite a bit more expensive than that.

You are correct, I can pick up a used SNES for around 30 gbp, but the thing is I have having loose consoles around. And I especially hate having two of a thing when one should suffice. I have just made a purchase of a NEC XM29 CRT monitor and hope that perhaps that will not have any problems with the SNES, otherwise I'll just go S-video.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 22, 2010, 10:53:22 PM
In case anyone is interested, and for the sake of future internet archive diggers. I got my NEC XM29, and my Rev 3 NTSC/U SNES gives me the same crippled image via the official Famicon RGB21 cables.

This settles it then, the third revision NTSC/U SNES has combination of resistors and/or capacitors that are not compatible with the official Famicom RGB cables.

The image is extremely dark and the colours look inverted at places, which leads my to make a uneducated guess that the picture level has been brought down too low by an extra set of 220 resistors, but what do I know.

Just a heads up for prospective buyers, check your SNES revision before you spend a lot of money on those RGB21 cables. Also, S-video works great.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Endymion on November 23, 2010, 03:57:20 AM
Quote from: kamiboy on November 22, 2010, 10:53:22 PM
In case anyone is interested, and for the sake of future internet archive diggers. I got my NEC XM29, and my Rev 3 NTSC/U SNES gives me the same crippled image via the official Famicon RGB21 cables.

This settles it then, the third revision NTSC/U SNES has combination of resistors and/or capacitors that are not compatible with the official Famicom RGB cables.

It does? Don't you want to try the cables bare to the monitor without the XRGB before saying that?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: kamiboy on November 23, 2010, 06:25:22 AM
I'll try it through an XSELECT once that parcel arrives, short of that, nay. Let someone else put in time and effort. I dont like the harshly sharp and pixelated imageI get directly from s-video, no point in trying to make it even more computer like than it already is.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: AlmostOriginal on April 21, 2012, 10:22:15 PM
This is probably one of the most interested threads i have ever read. I am planning to mod N64/Gamecube cables but so far i have only been making RF & Composite (NES, SNES, Master system, Megadrive, Atari jaguar and Turbo Grafx 16 and more)

Is this something interesting or should i post a new thread?

Huge cable project (http://www.youtube.com/watch?v=k6t8Fj2pgbc#)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: AlmostOriginal on January 13, 2013, 06:20:10 AM
I recently added the capacitor on my Composite cable but it stopped working.  ??? :'( When i remove the capacitor the cable works again.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on March 27, 2013, 05:18:52 AM
Very interesting topic to read. The quest of Link83 for the truth!  ;D

I'll probably be opening my SNES', N64's and RGB cables this year. If there are any specific things I can look out for, just let me know!


PS: Can't we have a 'bookmark' option in the forum?  :)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on July 07, 2013, 09:00:32 PM
Here's an image of my Gamecube RGB cable by Speedlink:
(http://i.imgur.com/fSpbdnX.jpg) (https://imgur.com/fSpbdnX)
(http://rguichelaar.dyndns.org/games/cables/gc_logic3_1024.jpg)


It's got 3x 220uF caps and resistors from pin 2 to 4 and pin 6 to 4. Can someone explain me that? (it's the only Nintendo scart cable I have with this construction).
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on July 07, 2013, 10:36:13 PM
Quote from: Link83 on July 15, 2008, 10:21:41 AM
Also, for anyone who may be interested in opening their Official Nintendo Scart Cables I took this picture and added some notes on how best to do it (The notes are abit small I know, but if you save the picture and then open it you can zoom in and read the text  ;)):-
(http://img515.imageshack.us/img515/8364/snes045zm1.th.jpg) (http://img515.imageshack.us/my.php?image=snes045zm1.jpg)
I saw an instruction somewhere with screenshots. Not sure if it was this one, but I'm looking for it now (struggling to open the official Gamecube RGB cable).

EDIT:
Ah, it was a guide from MMMonkey: http://www.mmmonkey.co.uk/official-pal-gamecube-rgb-cable-on-ntsc-consoles/ (http://www.mmmonkey.co.uk/official-pal-gamecube-rgb-cable-on-ntsc-consoles/)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Fix_Metal on July 08, 2013, 09:58:47 AM
Don't know if anyone replied to this earlier, but...
Quote from: Link83 on April 29, 2008, 10:31:00 PM
I managed to find my Official PAL Nintendo Composite cable and there appears to be more than just a resistor - there is also a 220uf capacitor aswell - anyone care to explain whats going on!
Same as what you'd need to output composite from Sony CXA encoder in SMS2 mod.
That gives you some filtering (can't Bode it atm) and DC decoupling.

QuoteCan anybody tell me what value resistor it uses? I guess its 180ohm. I have tried to work it out by the color banding but am not very good at it!
That's for RGB switching. +5V is going to #16, while +5V in series with the 180Ohm goes to the #8.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on July 08, 2013, 04:19:04 PM
Quote from: Link83 on January 23, 2009, 01:44:31 PM
I just wanted to update that I tested both a PAL SNES/N64 Composite cable and a PAL Gamecube Composite cable on a PAL N64 console.

Visually I couldnt see any difference using either cable (but maybe im not looking hard enough)

I then decided to measure the DC offset from the PAL N64. Using the PAL Gamecube Composite cable (75ohm resistor to ground and 220uF capacitor in series) it measured 0.00V as I expected.

Next I tried the PAL SNES/N64 Composite cable (75ohm resistor to ground) and somewhat surprisingly got readings betweens 0.7V and 1.35V DC - varying according to how bright the game picture was. During gameplay it seemed to average out at about 1V DC.

I am not sure what effect this DC offset would have on the picture quality, but I dont think it would be for the better. I have read in many audiophile forums that having a DC offset on headphone amplifiers higher than 20mV (0.02V!) can have a detrimental affect on the sound and can damage the speakers :o, so I assume a 1V DC offset on Composite video would be the same/similar(?)

All this suggests that to me their definitely should be a 220uF capacitor in series on the PAL N64 Composite line aswell as the 75ohm resistor to ground, and that Nintendo just cheaped out on making the PAL N64 Composite cable because they could get away with it ::)

I havent been able to test the PAL SNES yet as I have just accidentally blown the fuse on my console :( (Even though I 'discharged' it for 10 seconds first) but when I get a new fuse I will compare the PAL SNES aswell and update this thread.

Sorry if anyone finds this info boring - I realise it wont interest many as its only Composite Video!
Quote from: AlmostOriginal on January 13, 2013, 06:20:10 AM
I recently added the capacitor on my Composite cable but it stopped working.  ??? :'( When i remove the capacitor the cable works again.
What's the theory on the fact that adding the capacitors on the composite cable makes it stop working? (while they should be there)
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on July 08, 2013, 06:39:27 PM
Quote from: Link83 on July 20, 2008, 03:35:28 AMAlso I thought it might be good to point out that prior to recieving this Official SNES Scart cable, I had been using an Official Gamecube Scart cable on my SNES with no problems whatsoever. It could just be because my TV is able to handle the signal levels better than other peoples (which often show no picture or fades to black after a few seconds)

Alternatively could it be there is a difference on the video lines of my PAL SNES? It is the very last revision made in 1995, with the code SNSP-CPU-1CHIP-01 printed on the motherboard. Heres some pictures of my SNES which also show the video lines:-
(http://img175.imageshack.us/img175/1381/snes009ty6.th.jpg) (http://img175.imageshack.us/my.php?image=snes009ty6.jpg)(http://img115.imageshack.us/img115/4007/snes005dx2.th.jpg) (http://img115.imageshack.us/my.php?image=snes005dx2.jpg)
(http://img115.imageshack.us/img115/8634/snes012ba2.th.jpg) (http://img115.imageshack.us/my.php?image=snes012ba2.jpg)(http://img115.imageshack.us/img115/9765/snes011pb9.th.jpg) (http://img115.imageshack.us/my.php?image=snes011pb9.jpg)
Was it so that the PAL 1-chip SNES supports the Gamecube cables? (edit: yes it does!)
If I use the official GC RGB cable with my (early revision) SNES it turns dark, as expected I would say.


EDIT:
Guess this answers that (unless I interpretet it wrongly)
Quote from: viletim on July 20, 2008, 04:32:23 PMRegarding the RGB output circuit of the PAL SNES - I've just pulled apart one of mine (1992 model) and had a look at the board. Like MKL said, there's only two 30 ohm resistors there! Something's not right. I'll trace it out again...

Maybe Nintendo revised their video output circuit in later models. You put a cap in series with the video from the 1992 PAL SNES and nothing will come out.
Quote from: viletim on July 27, 2008, 08:50:15 PMI examined the internals of my 1992 PAL SNES and can confirm the presence of a 30 ohm resistor in series with red, green, and blue. The circuit looks like: (http://members.optusnet.com.au/eviltim/gamescart/o_snesp.png)
If you put a capacitor in series with the signal it won't work. Nintendo must have changed the circuit somewhere between 1992 and 1995. I presume that their official cable works perfectly with both versions.


EDIT:
Additionally, what would the effect be if the 75ohm resistor was not on the composite line (and only on R, G, B)?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on July 30, 2013, 02:38:09 PM
Quote from: Link83 on January 16, 2009, 04:34:40 AMSo it is different to the PAL Gamecube Composite cable as that had a little circuit board with a 220uF capacitor in series aswell as the 75ohm resistor to ground (See first page of this thread for pics)
Link83 (or anyone else), you still got the Gamecube composite pics somewhere? (images in the first post are dead)
Found this one:
(http://i.imgur.com/F3fBTEL.jpg) (https://imgur.com/F3fBTEL)

Also I'm wondering. We say there should be a 220uF capacitor in series on the PAL N64 Composite line aswell as the 75ohm resistor to ground, and that Nintendo just cheaped out on adding the cap in the the PAL N64 Composite cable because they could get away with it. The 220uF cap with the GC RGB cable results in a black picture with the SNES (and FRA S-RGB modded N64 via missing components). A composite cable with 220uF cap would not?

Is it also official that a GC RGB cable does in fact work with a PAL 1-CHIP SNES? <-- yup, works!
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: unshe on July 30, 2013, 06:50:24 PM
About Gamecube cable and PAL 1-chip snes, YES it is working perfect. Tested on PAL 1-chip-01 and Pal 1-Chip-02.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on August 05, 2013, 12:06:40 AM
Nice.

Today I tested with (official) composite on my Sony Bravia LCD, which makes a BIG difference compared to my JVC 50hz CRT. The PAL launch N64 shows A LOT of dot crawling, while the NTSC N64 doesn't have this issue (just the unsharp edges you have with composite). So that was kinda new to me, since I'm used that composite video always has dot crawling.

Other than that, I don't see any difference between the PAL SNES composite cable and the PAL GC composite cable in video quality on the N64, just like @Link83  concluded.
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on March 07, 2020, 11:11:29 PM
Unfortunately not much activity here  ;)
Trying to pick up my N64 mod projects again (after buying a house, getting married and becoming a dad O_o ).
Still no activity from Link83 around here?
Title: Re: Official Nintendo AV Cables for SNES, N64 and Gamecube - resistors & capacitors?
Post by: Shadow_Zero on July 08, 2020, 12:03:08 AM
Quote from: Link83 on January 23, 2009, 01:44:31 PMI just wanted to update that I tested both a PAL SNES/N64 Composite cable and a PAL Gamecube Composite cable on a PAL N64 console.

Visually I couldnt see any difference using either cable (but maybe im not looking hard enough)

I then decided to measure the DC offset from the PAL N64. Using the PAL Gamecube Composite cable (75ohm resistor to ground and 220uF capacitor in series) it measured 0.00V as I expected.

Next I tried the PAL SNES/N64 Composite cable (75ohm resistor to ground) and somewhat surprisingly got readings betweens 0.7V and 1.35V DC - varying according to how bright the game picture was. During gameplay it seemed to average out at about 1V DC.

I am not sure what effect this DC offset would have on the picture quality, but I dont think it would be for the better. I have read in many audiophile forums that having a DC offset on headphone amplifiers higher than 20mV (0.02V!) can have a detrimental affect on the sound and can damage the speakers :o, so I assume a 1V DC offset on Composite video would be the same/similar(?)

All this suggests that to me their definitely should be a 220uF capacitor in series on the PAL N64 Composite line aswell as the 75ohm resistor to ground, and that Nintendo just cheaped out on making the PAL N64 Composite cable because they could get away with it ::)

I havent been able to test the PAL SNES yet as I have just accidentally blown the fuse on my console :( (Even though I 'discharged' it for 10 seconds first) but when I get a new fuse I will compare the PAL SNES aswell and update this thread.

Sorry if anyone finds this info boring - I realise it wont interest many as its only Composite Video!
Following up on @Link83's post in an other topic, it's interesting to debate (and test) if the missing 220uF cap on composite video could result in sync issues (which could also impact RGB, if not using csync).
Unless I'm totally talking/thinking gibberish now! At least I'll try some tests with my RGB modded FRA N64's, since I had various results in video output...


EDIT:
Found an interesting quote from @unshe:
https://nfggames.com/forum2/index.php?topic=37.msg34189#msg34189
Quote from: unshe on July 31, 2013, 12:54:13 AMABout resistors/caps on CVBS.. it is used only for Sync, so if the sync signal is still "good for the tv" it will work. So resistors or caps on CVBS are not so important...