Retro_Console_Accessories ebay cables could cause damage...?

[Fudoh]

though I think only the Saturn was C-Sync

then only Saturn. If the console uses composite video or luma to start with, then there's nothing to worry about.

[FBX]

I just added a video to the csync page that might help anyone who wants to figure out if their cables are okay: http://www.retrorgb.com/csync.html

Finally a clear and concise answer to my questions! THANK YOU!

(only thing extra I would like to have seen was the actual hooking up of the scope to the components, but that would just be the cherry on top)

-FBX

[Fudoh]

I just added a video to the csync page that might help anyone who wants to figure out if their cables are okay: http://www.retrorgb.com/csync.html

you could add that all LM1881 based strippers output TTL as well, so whenever there's a LM1881 used in a Scart cable it requires a 470 ohm cap as well. I've seen enough LM1881 outputs being connected without it.

And I'd like an info added about the PC Engine/TG16's sync output. CSync is present on the extension port, but somebody would need to confirm that it uses full TTL level.

[FBX]

so whenever there's a LM1881 used in a Scart cable it requires a 470 ohm cap as well.

470 Ohm resistor I think you mean. The cap after the resistor is to prevent backflow of electricity, thus protecting your console from being fried. I think I have this right anyway (trying to move up from white belt knowledge ).


-FBX

[Fudoh]

resistor - of course.

[RGB0b]

So I bought the NTSC versions of their SCART cables, though I think only the Saturn was C-Sync. Dates listed. So which should I consider having issues?

1/27/2013 Genesis 2/32X
1/27/2013 Genesis 1/SMS (mono)
1/27/2013 Genesis 1 (stereo jack)
8/26/2014 SNES
2/15/2016 Saturn (Luma Sync)

Personally, I'd check them all, just to be safe. Also, note that the Saturn cable will not need any components on the sync line, as you're using luma.

only thing extra I would like to have seen was the actual hooking up of the scope to the components, but that would just be the cherry on top

That's for another video Besides, I'm still saving up to get a scope of my own (the Patreon money is all going to the office)...those scope caps were taken by Ste, who was a MASSIVE help in making this video.

you could add that all LM1881 based strippers output TTL as well, so whenever there's a LM1881 used in a Scart cable it requires a 470 ohm resistor as well. I've seen enough LM1881 outputs being connected without it.

That absolutely needs to be addressed, but I wanted to stay as on-topic as I could for this video: How to check cables / why you need a scope and not just a multimeter. I think that's info that would be perfect for the sync video I'm working on; I posted a (bad) rough draft awhile back and I've meant to go back and re-shoot it, but my stupid "real" job keeps taking up all my time ;p For the record, all the LM1881 pages on the site have been updated, saying to add the 470ohm resistor.

And I'd like an info added about the PC Engine/TG16's sync output. CSync is present on the extension port, but somebody would need to confirm that it uses full TTL level.

I'm not the guy for that video, but I'll keep annoying Voultar until he gets around to doing it

[FBX]

...those scope caps were taken by Ste, who was a MASSIVE help in making this video.

Ste is a super man. A lot like Voultar. I bet if you combine the retro round table group, you'd end up with:

[pyroman512]

Here's a pic of the inside of my cable if anyone is interested, btw it is a genesis 2 cable
http://www.mediafire.com/convkey/d2d1/o ... psmizg.jpg

About cables that look like this. I opened my genesis II cable last night and saw the board and didn't really understand what it was doing so I just closed it back up for now. But I emailed RCA about it and she said that these cables should still be safe. It is still a buffer circuit but there is a 470 ohm resistor from that board to the csync pin.

Her response:

Hi,

You need do nothing, this is just a buffer IC with a 470 ohm resistor on the output line. I'm confident of this one. A lot of drama has been happening of late, but this particular circuit is safe. It was merely incompatible with certain mods, probably because of the presence of this resistor, (I'm assuming they are 75 ohm attenuated already) but perhaps due to the buffer circuit - I have not tested the output from these mods but I *have* tested the output from the Genesis 2. All other Sega consoles with this port should also be safe, they will certainly drop into safe vpp ranges with this circuit.

Also my SNES shielded cable is just a pass through cable so I'm going to have to add the resistor or set all the consoles to 75ohm. I think I'd rather have the cable do the attenuation so that years down the line my SNES output will still match a stock SNES.

[Greg2600]

So I bought the NTSC versions of their SCART cables, though I think only the Saturn was C-Sync. Dates listed. So which should I consider having issues?

1/27/2013 Genesis 2/32X
1/27/2013 Genesis 1/SMS (mono)
1/27/2013 Genesis 1 (stereo jack)
8/26/2014 SNES
2/15/2016 Saturn (Luma Sync)

Personally, I'd check them all, just to be safe. Also, note that the Saturn cable will not need any components on the sync line, as you're using luma.

Well I'd rather not disassemble the cables, and I'm likely to break them. I may just try to contact them directly. Thanks.

[bobrocks95]

I just added a video to the csync page that might help anyone who wants to figure out if their cables are okay: http://www.retrorgb.com/csync.html

Thanks for the video Bob, concise and to the point. I tried measuring my SNES CSync cable from RCA, since as I understand you can do that without opening it given it doesn't have capacitors on the sync line. I read 177 Ohms, so... Not quite right but it seems like it has something on the Csync line?

The SNES multiout is hard to get a probe into, so I think I was hitting the pin for Blue as well, would that make my measurements pointless?

[Ripthorn]

Does anyone know if it is safe to use this adapter?
http://www.ebay.com/itm/Micomsoft-XRGB- ... 1621505666

[RGBSource]

While all of this concern originally stemmed from viletim's post (don't think the idea would have surfaced otherwise), retro gaming cables has some design oversights too.

https://www.retrogamingcables.co.uk/nin ... SYNC-CSYNC

Viletim explicitly provided info for how to correctly apply the LM1881 for video level output almost TWO YEARS AGO, yet it continues unaddressed.

Spoiler

Resistor and cap for Rset are included, but not needed. No 470 ohm resistor between output and SCART pin 20. A simple bypass switch or jumper should be added so that the correct output level is selectable.

Even regular CSync cables without any built-in circuit are problematic (MD, SNES). He has been selling these TTL CSync cables for years as if nothing were wrong with them. When I finally realised how incompatible they are and that there is a possible chance of damaging equipment I sent him a mail about the matter, no reponse of course. He is now selling properly attenuated cables for 36 pounds so his business seems to run quite well.

Confusing. So the csync N64 cable from Retro Gaming Cables is potentially at issue? Are their current Genesis and SNES cables okay, or not?

Yes, the current CSYNC N64 cable has a LM1881 with its output fed directly (TTL level) to pin 20 and doesn't contain a 470 ohm series resistor:
https://www.retrogamingcables.co.uk/nin ... SYNC-CSYNC

There's another SNES style cable from RGC that claims to provide "CSYNC 75 ohm":
https://www.retrogamingcables.co.uk/pac ... gold-scart

Two different cables from the same seller.

[RGBSource]

Not quite right but it seems like it has something on the Csync line?

Likely repurposing a 180 ohm resistor typically used for SCART switching pins 8 & 16. The reason why 330 was specified by viletim for the SNES from what I've learned is that the original circuit has a 100 ohm series resistor. (100+330).

Spoiler

The SNES multiout is hard to get a probe into, so I think I was hitting the pin for Blue as well, would that make my measurements pointless?

No, it's OK. You should get the same reading either way.

Also, as it's been mentioned before - Adding resistors to attenuate CSYNC should be placed at the source end, not at the destination. This is the same concept of needing to put 75 ohm resistors at the source end when building Sega Genesis/MD RGB cables to reduce cross-coupling of signals, among other things.

[bobrocks95]

Thanks for the clarifications! If ~430 Ohms is the goal, I'm hitting ~280. I guess that means I'm pumping extra voltage into my equipment, though not as bad as if I were using a completely passive cable.

Overall in my case I don't think it would be worth trying to crack open my connectors- both sides are glued shut, and I custom-ordered cables with D-SUB connectors at the output, which is way more difficult to work with than the typical clamshell SCART head you see.

For anyone curious, this is a retro_console_accessories SNES CSync cable purchased Feb. 11, 2016, which is fairly recently I'd say. I wonder if her designs have changed further since then?

[RGB0b]

Here's a pic of the inside of my cable if anyone is interested, btw it is a genesis 2 cable
http://www.mediafire.com/convkey/d2d1/o ... psmizg.jpg

About cables that look like this. I opened my genesis II cable last night and saw the board and didn't really understand what it was doing so I just closed it back up for now. But I emailed RCA about it and she said that these cables should still be safe. It is still a buffer circuit but there is a 470 ohm resistor from that board to the csync pin.

Her response:

Hi,

You need do nothing, this is just a buffer IC with a 470 ohm resistor on the output line. I'm confident of this one. A lot of drama has been happening of late, but this particular circuit is safe. It was merely incompatible with certain mods, probably because of the presence of this resistor, (I'm assuming they are 75 ohm attenuated already) but perhaps due to the buffer circuit - I have not tested the output from these mods but I *have* tested the output from the Genesis 2. All other Sega consoles with this port should also be safe, they will certainly drop into safe vpp ranges with this circuit.

Also my SNES shielded cable is just a pass through cable so I'm going to have to add the resistor or set all the consoles to 75ohm. I think I'd rather have the cable do the attenuation so that years down the line my SNES output will still match a stock SNES.

About that pic (http://www.mediafire.com/convkey/d2d1/o ... psmizg.jpg) - Can you take pics of both sides of that board?

[RGB0b]

Well I'd rather not disassemble the cables, and I'm likely to break them.

I highly doubt you'll break them.

Thanks for the video Bob, concise and to the point. I tried measuring my SNES CSync cable from RCA, since as I understand you can do that without opening it given it doesn't have capacitors on the sync line. I read 177 Ohms, so... Not quite right but it seems like it has something on the Csync line?

The SNES multiout is hard to get a probe into, so I think I was hitting the pin for Blue as well, would that make my measurements pointless?

I sometimes use a "dental pick" to touch pins that are hard to get to with a probe, then touch my probe to that: http://www.ebay.com/itm/140793018626
You could also open the SNES case and probe the pins on the bottom of the multi-out. That's a lot of disassembly though.

Also, as it's been mentioned before - Adding resistors to attenuate CSYNC should be placed at the source end, not at the destination. This is the same concept of needing to put 75 ohm resistors at the source end when building Sega Genesis/MD RGB cables to reduce cross-coupling of signals, among other things.

Correct, but it's better to have them in the SCART head then not at all

[Thomas83lin]

About that pic (http://www.mediafire.com/convkey/d2d1/o ... psmizg.jpg) - Can you take pics of both sides of that board?

Sure can, because luckily I've removed it. It's soldered in really good. here's a pic of the other side.
http://www.mediafire.com/convkey/4f32/5 ... hk6ozg.jpg

edit: I've cleaned the chip up and its a
HB125Q
41K G4
CQRV

It seems it may be nothing more than a buffer. when I purchased my cable it was advertised as boosted csync. I decided to just remove it and redo the csync part.

[RGBSource]

Also, as it's been mentioned before - Adding resistors to attenuate CSYNC should be placed at the source end, not at the destination. This is the same concept of needing to put 75 ohm resistors at the source end when building Sega Genesis/MD RGB cables to reduce cross-coupling of signals, among other things.

Correct, but it's better to have them in the SCART head then not at all

If you're going to fix a potential problem, do it correctly, not half-assed!

[RGB0b]

Sure can, because luckily I've removed it. It's soldered in really good. here's a pic of the other side.
http://www.mediafire.com/convkey/4f32/5 ... hk6ozg.jpg

edit: I've cleaned the chip up and its a
HB125Q
41K G4
CQRV

It seems it may be nothing more than a buffer. when I purchased my cable it was advertised as boosted csync. I decided to just remove it and redo the csync part.

Thanks for the pic. Correct, that's not the amp, just a buffer similar to the logic gate circuit Tim posted awhile back. In the case of Genesis sync, I'm not sure if that offers any real advantage over using a cap and resistor (but remember, I'm not an EE). I'll be sticking with the resistor and cap, but maybe Tim can chime in if he sees this and let us know if he thinks there's any benefit to using that instead.

Also, as it's been mentioned before - Adding resistors to attenuate CSYNC should be placed at the source end, not at the destination. This is the same concept of needing to put 75 ohm resistors at the source end when building Sega Genesis/MD RGB cables to reduce cross-coupling of signals, among other things.

Correct, but it's better to have them in the SCART head then not at all

If you're going to fix a potential problem, do it correctly, not half-assed!

I'm not sure what you mean by that. If you're talking about the cable manufacturers, yes, they should be putting the resistors in the DIN side...and I beleive they have been for awhile now (the 2nd SCART cable I showed in the video was a few years old).

As far as people modifying their own cables...that's tricky. Some DIN's are molded and can't be opened at all. Others can probably be pried open, but you'd have to glue it back together. Bottom line: I wouldn't suggest people throw out their cables if the sync resistors are in the SCART head...and while having it there isn't as good as having it in the DIN, it's WAY better then not having it at all.

[Voultar]

Also, as it's been mentioned before - Adding resistors to attenuate CSYNC should be placed at the source end, not at the destination. This is the same concept of needing to put 75 ohm resistors at the source end when building Sega Genesis/MD RGB cables to reduce cross-coupling of signals, among other things.

Correct, but it's better to have them in the SCART head then not at all

If you're going to fix a potential problem, do it correctly, not half-assed!

Yeah, most of the time the plug side of the cable is potted in 2-part epoxy. So good luck with that.

Also, while it's true about putting your passives on the source side. It's important to understand that Composite-Sync isn't a video transmission line. So the benefit of putting business down on the source-end doesn't carry quite the same benefit as it does for your video lines. The idea is to mitigate capacitance coupling and the capacitance load on your video/audio lines, C-Sync isn't nearly as important.



I talk about this in greater length in an interview I did with Bob a year or so ago. It covers a great deal of this. I certainly don't want people thinking they have to gut the plug-side of their cable to remedy an improperly attenuated logic sync signal. in a cable that they purchased..

[Ikaruga11]

Who makes the best RGB SCART cables?

[FBX]

Who makes the best RGB SCART cables?

While there was the issue of Retro_Console_Accessories's cables that came up, my own coaxial upgraded cables I ordered from her last month were spot-on correctly attenuated for each console. That said, she uses more traditional approach with loose caps on the scart end and resistors as needed in the console end.

The other top maker is the UK-based RetroGamingCables. They make use of a PCB in the SCART end of the cable, and I hear they make certain the cables are properly attenuated as well.

I always buy the upgraded extra-shielding cables, but it can be expensive. I think on RGC's site, they refer to them as some silly name like "pack-a-punch".

-FBX

[Guspaz]

Retro Gaming Cables only offers (at the moment, anyhow) very few cables in "Pack-A-Punch", just Genesis, Snes, and scart-to-scart, and two of those three are typically sold out.

His regular cables are still properly shielded, the difference is that the normal cables are shielded for the whole cable, while pack-a-punch replaces the internal wires with coax, which sort of goes beyond even shielding individual wires (coax is a level beyond just shielding). I believe they are similar to RCA's coax option.

[FBX]

...while pack-a-punch replaces the internal wires with coax, which sort of goes beyond even shielding individual wires (coax is a level beyond just shielding). I believe they are similar to RCA's coax option.

Sounds like it. The coax ones I get from RCA have each line going like this: center conductor, insulation jacket, copper ground layer, outer insulation jacket.

[RGB0b]

you could add that all LM1881 based strippers output TTL as well, so whenever there's a LM1881 used in a Scart cable it requires a 470 ohm cap as well. I've seen enough LM1881 outputs being connected without it.

After reading your post, I realized I absolutely should have added sync stripper info, so I just re-uploaded the video with a section on that (as well as two minor mistakes corrected). Hopefully this one covers all ground: https://youtu.be/Z3sE3uk5kPU

[Ikaruga11]

So I should get Retro_Console_Accessories cables?

[tjstogy]

Yeah, sometimes, maybe, sometimes, not other times. RetroRGB and his round table speak about this stuff at length. I’d follow it on YouTube if I were you.. and watch previous episodes on YouTube. And follow Voultars channel. Hes a smart dude, even if his camera and mic never work and he <3’s Adam Koralik

.....(jk, bro)

So I should get Retro_Console_Accessories cables?

[FBX]

In all honesty if you get coaxial upgraded cables, R_C_A does top notch work with them. The ones I ordered and got last month all passed the multimeter tests that Bob shows how to do in his youtube video.

[bobrocks95]

In all honesty if you get coaxial upgraded cables, R_C_A does top notch work with them. The ones I ordered and got last month all passed the multimeter tests that Bob shows how to do in his youtube video.

That's good to hear, I'd guess they've been refined over the past year or two to get proper attenuation.

Which cables did you test? Were they all ordered about a month ago? (Sorry if you've already said)

[FBX]

In all honesty if you get coaxial upgraded cables, R_C_A does top notch work with them. The ones I ordered and got last month all passed the multimeter tests that Bob shows how to do in his youtube video.

That's good to hear, I'd guess they've been refined over the past year or two to get proper attenuation.

Which cables did you test? Were they all ordered about a month ago? (Sorry if you've already said)

Yeah I placed the order for them a little over a month ago; probably closer to two months. I commissioned lot done of a couple SNES csync cables, Genesis csync, Saturn Luma sync, PS1 & 2 Luma sync, and a couple other odds and ends. All tested as correctly built (resistors in din plug end, caps in the other, no boosting chips, etc.).