S-video mod schematic for the schematic illiterate (For TG-16/Duo etc)

[Sensato Black Lion]

There is a lot of interesting info in that post NightWolve. I will definitely read this entire post and look more deeply into it.

http://quebecgamers.com/sensato/Workshop/PCE_svid.htm

Great job on this BTW; a Javascript mouseover to switch between the S-Video shot and back was a good idea. My Turbo Duo Composite was pretty shitty I always thought, I think your shots capture it, even though it's with a capture card.

Thanks! The mouse over idea wasn't mine though. I borrowed it from a guy who had PCE Screenshots vs Wii Screenshots. I believe it was Black Tiger on his Superpcenginegrafx site. There were some Virtual Console screenshots vs PCE screenshots done with the rollover script. Can't seem to find that page anymore.

[ProfessorProfessorson]

Glad that people are using this mod to much success, and also finding ways to improve on it. At any rate, because I don't want anyone to be confused as to who originated this mod, actual thanks should go to the others who worked on it originally, which did not include me (certain Genesis II region mod, or Sony CXA1145 svideo mod, sure I was involved, but this one, nope, not me). All I did was do my own testing once I got a couple decks again, and provided a easy to understand schematic for some to use who might have a harder time with a more traditional one.

The guys who actually came up with this mod originally should be taking the credit for it. TheSteve was one of them I believe, and also one or two others. I don't think Drakon can be included in that list though, since whatever he was doing was going in a separate direction, removing components and using diff values, etc.

As for the color bleeding you are getting Black Lion, I cant really comment on that. I don't have that kind of issue on the decks I have done. Hopefully you can get it sorted out.

[ApolloBoy]

If you're getting color bleeding through S-video, try checking your ground connections. I've found that leaving the ground unconnected on either the chroma or luma lines can lead to some horrible color bleeding.

[Sensato Black Lion]

If you're getting color bleeding through S-video, try checking your ground connections. I've found that leaving the ground unconnected on either the chroma or luma lines can lead to some horrible color bleeding.

I'll check that thanks. I went and got some new .001 uf caps from a local shop. I tested the circuit with a cap from the batch he gave me and now I get no colors at all! Nice.

I asked for 1 nanofarads ceramic caps but he apparently gave me 1 picofarads caps. I also paid 50 cents each which seems a bit expensive to me. I'm always glad to buy local but sometimes it's a bit hard considering the difference in price. In this case, it still doesn't make the mod very expensive so I guess I shouldn't really complain.

[thesteve]

that is a bit high
you can leave the cap out as well

[chipperkwah]

For the 220 ohm resistor, what do you recommend? 1w? 1/4w?

[NightWolve]

The smallest are perfectly fine, 1/8 watt. Get a 500 pack from somewhere like this:

http://www.radioshack.com/product/index.jsp?productId=2994585

A solid 220 Ohm resistor will actually be like ~215 Ohms when measured, which is just about perfect resistance for the amplified output of a 2n3904 or S8050 transistor when powered with a +5V source for the Luma signal.

[chipperkwah]

Right on, thanks for the info. Here are the digikey part numbers for what I'll be using in case people don't feel like digging through their catalog. I think it should be fine to use 30awg wire to get the 5v from the expansion port to the SS8050, someone correct me if I should use thicker wire or stranded wire.

S-video jack - CP-2840-ND
SS8050 transistor - SS8050CBU-ND
220 ohm resistor - CF18JT220KCT-ND
SPDT rocker switch (if you want to retain composite) - 450-1016-ND

Other Stuff:

Wire wrap 30 AWG that I like from sparkfun - https://www.sparkfun.com/products/8031
Solder from sparkfun - https://www.sparkfun.com/products/10240
S-video cable from monoprice - http://www.monoprice.com/products/product.asp?c_id=102&cp_id=10207&cs_id=1020701&p_id=2896&seq=1&format=2

[Sensato Black Lion]

I did a quick test earlier this morning and I must admit that I'm impressed with the "new mod".

I have some major color bleeding for now though but I blame the old .001 uf cap I used. The bleeding I have does not appear in screencaps seen in previous posts from other members.

I found out a few weeks ago that the "bleeding" I was talking about only occurs on one of my monitor. Turns out that that monitor doesn't like the composite video through the cap for chroma. The bleeding was all gone when I removed the resistor mentionned in Drakon's variant of the mod. I thought this might interest some of you...

[NightWolve]

SS8050 transistor - SS8050CBU-ND

FYI, ebay's the way to go for this transistor.

http://www.ebay.com/itm/100-PCS-S8050D-S8050-8050-NPN-Transistor-NEW-TO-92-/

Pay $4 bucks with shipping, get 100 pieces and have plenty to spare in case of other projects, etc. You must specify to the seller that you want the S8050, not the other 2 types listed.

S-video jack - CP-2840-ND

Fair warning on this female S-Video jack part: I bought the same one from markertek and it did NOT include the hexagonal nut as pictured in the photo! I had to make my own, a really improvised solution...

I found out a few weeks ago that the "bleeding" I was talking about only occurs on one of my monitor. Turns out that that monitor doesn't like the composite video through the cap for chroma. The bleeding was all gone when I removed the resistor mentionned in Drakon's variant of the mod. I thought this might interest some of you...

Hmm, that's good to know, so some monitors might not like the Chroma filtered out of a Composite signal via a simple capacitor. You might wanna think about my idea here though of a switch instead of permanently breaking Composite support via resistor removal. A little more work, but better than permanently breaking it. It's based on what I did for my SNES:



So in the case of a TG-16/Turbo Duo, when the switch is in the C position (or Off), Luma is disconnected from the internal Composite circuit and all you're getting out of the yellow Composite output is a pure Chroma signal. When you disconnect your S-Video cable and need to go back to using Composite, you flip the switch and voila, it's back to working normally, etc. Note that modern TVs are phasing out S-Video support while still mostly maintaining Composite support, so you really don't want to permanently break it...

My trick above was so that I didn't need to drill a hole for a 4th yellow RCA jack. When it's in the C position, the green jack is outputting regular Composite. When it's in the opposite position, it's outputting pure Luma for use via a Component connection as intended, etc. I don't have a 'L' sticker to put there for 'Luma'. But anyway, you get the idea. You'd have a switch just like that next to your female S-Video output jack and the switch would interrupt a trace of the Luma signal; break the trace, connect 2 wires to both ends and to the switch. That's about it, just gotta find a good point to break/cut the trace. I hope this was a PC Engine with a normal sized resistor and not a surface mount one, or otherwise, I guess you probably broke it for good and didn't care at the time.

[ProfessorProfessorson]

What was the name of the monitor/model number for the one having issues? That has to be a pretty rare event because even my sucky Dynex crt TV worked with the s-vid mod fine. I've yet to run into issues with any of my Tvs via the mod (I own 5 tvs, plus cap card also which it worked on fine), so makes me wonder.

[Sensato Black Lion]

Hmm, that's good to know, so some monitors might not like the Chroma filtered out of a Composite signal via a simple capacitor. You might wanna think about my idea here though of a switch instead of permanently breaking Composite support via resistor removal. A little more work, but better than permanently breaking it.

I hope this was a PC Engine with a normal sized resistor and not a surface mount one, or otherwise, I guess you probably broke it for good and didn't care at the time.

Yeah, there is no way I'm breaking composite compatibility. The mod was done on a US Duo and I aready installed a composite/svideo switch. I'm curious to know what that switch does on your SNES...

What was the name of the monitor/model number for the one having issues? That has to be a pretty rare event because even my sucky Dynex crt TV worked with the s-vid mod fine. I've yet to run into issues with any of my Tvs via the mod (I own 5 tvs, plus cap card also which it worked on fine), so makes me wonder.

The monitor is an LG M228WA. I've had it for about 5 years and, from what I recall, I never had any problem with any other svideo output/mod (and I've tried many different svideo mods on it). Other mods still look good on it to this day.

Not that it would make any difference but, I get the same "bleeding" results with the mod on that monitor whether it's done on a TG16 or an american Duo.

[ProfessorProfessorson]

Is anyone one else here running into that issue that Black Lion is having? Also, Black Lion, I've read both good and bad things about your monitor. That one hails from back in 07 when they were kind of skimping on the SD inputs processing, so I am not too surprised that you are having a issue on it, even if it does seem like a random fluke for you. You're monitor maintains like a 6.5 out of 10 rating on Testfreaks. That is really not a good rating at all for a LCD. Pretty much the only really good reviews for it are from people who only use it for modern equipment.

If anyone else is having the same or similar issue with this mod as Black Lion, what tv are you using? LCD, CRT, make, model, year, etc?

[NightWolve]

Yeah, there is no way I'm breaking composite compatibility. The mod was done on a US Duo and I aready installed a composite/svideo switch.

Ah good.

I'm curious to know what that switch does on your SNES...

Already mentioned, 2nd paragraph under the photo. Got the idea from new TV sets that had 3 RCA jacks for Component, but the green jack is colored half green/half yellow to indicate that it'll accept either a Composite signal or a Luma if using Component. I wouldn't be smart enough to do a digital automatic switch, so a manual switch is what I could do and that really is the best way technically (no contamination possible at all). The reason manufacturers are doing it is to save on real estate. Instead of 4 female RCA jacks in the input module, you'll only need 3. So lately, all you see on input modules is RF for the antenna, 3 RCA jacks for Component/Composite and 2 or more HDMI inputs, etc.

[Sensato Black Lion]

Is anyone one else here running into that issue that Black Lion is having? Also, Black Lion, I've read both good and bad things about your monitor. That one hails from back in 07 when they were kind of skimping on the SD inputs processing, so I am not too surprised that you are having a issue on it, even if it does seem like a random fluke for you. You're monitor maintains like a 6.5 out of 10 rating on Testfreaks. That is really not a good rating at all for a LCD. Pretty much the only really good reviews for it are from people who only use it for modern equipment.

If anyone else is having the same or similar issue with this mod as Black Lion, what tv are you using? LCD, CRT, make, model, year, etc?

From what I've seen, most complaints I've read about this monitor is that it has bad sound. I'd also assume that most of the people who bought this monitor were to use it with modern stuff.

This MIGHT be the ONLY monitor with which this newer svideo mod causes trouble, but untill I'm 100% sure of this, I won't take any chances modding systems for others without adding a composite/svideo switch.

@NightWolve: oups sorry, looks like I didn't read that last paragraph. Hm, well thought about that composite/component switch!