Genesis Model 2 (CXA1145) S-Video mod. Where do I get the +5 volt from?

[ApolloBoy]

Using 220 uf on the Chroma and 27 uf on the luma

Ohms, not microfarads.

[Drakon]

My images were taken using a capture device which is way more sensitive than a tv. Here's how master system stuff looks on my crt using this circuit:





Also the 3904 transistor will work fine for this. I just made that schematic before I got some 2n3904s. I think my personal system is using a 2n3904 actually.

[Majestic_Lizard]

Ohms, not microfarads.

I didn't really confuse the two, it was a typo. Thanks for pointing it out though. Changed.

My images were taken using a capture device which is way more sensitive than a tv. Here's how master system stuff looks on my crt using this circuit:





Also the 3904 transistor will work fine for this. I just made that schematic before I got some 2n3904s. I think my personal system is using a 2n3904 actually.

Drakon, that is a CRT. I'm using an LCD. Even at 68 ohms there are no lines the way I'm doing it on a CRT with S-Video.

I'm satisfied with my results on the LCD. Not trying to start an argument.

[Drakon]

I'm not making an argument. You asked, I explained. Also your crt must be total sh#t. My crt has very noticable jailbars with 68 ohms on chroma. I can still see the jailbars on my crt at 220 ohms but it's good enough for master system games so smeh. Not everyone owns a crt that's a blurry mess.

[evildragon]

Heh, Drakon calling someones TV shit, while he uses a Thomson Consumer Electronics TV.

[Drakon]

Heh, Drakon calling someones TV shit, while he uses a Thomson Consumer Electronics TV.

Which displays a clean picture that picks up interference just as well as a flatscreen. I can't see any other reason why his tv doesn't pick it up other than it being sh#t. I'm assuming he's smart enough to turn up the sharpness on his tv if it has that feature.

[Majestic_Lizard]

I'm not making an argument. You asked, I explained. Also your crt must be total sh#t. My crt has very noticable jailbars with 68 ohms on chroma. I can still see the jailbars on my crt at 220 ohms but it's good enough for master system games so smeh. Not everyone owns a crt that's a blurry mess.

First of all, Drakon, thank you for all of your help. You and Ace are truly brilliant with electronics. With your advice I was able to get a fairly crystal clear picture on my 32 inch Magnavox HD LCD. The first mod of the CXA1145M that I did, I used 75 ohms (not 68, as it turns out). On a CRT that has S-Video there were no vertical lines (at least, none that I noticed). The vertical lines only showed up on my LCD. It was on the LCD that I wanted to get rid of the vertical lines, not on the CRT in which I did not notice them.

As far as calling my television expletives or suggesting it is blurry, I'm not sure where that is coming from. The 32 inch HD LCD is not blurry at all. The vertical lines didn't even show up on the CRT with S-video I was using. They just showed up with the LCD, and you told me exactly how to eliminate that problem. However, I misspoke earlier as I had actually used 75 and 130 ohms, and never 68. I only used 68 (and I'm going to switch it for a 130) when I made my ohms switch (for the SMS). I'm now using 220 ohms as you suggested.

One of the reasons I want to get this mod down pat on the Genesis consoles is that I have several of them that I don't need. When I sell them online (unmodified), people usually return them saying they don't look good on their LCD (via composite) and are therefor "broken". Then I get the console back and it turns out there is NOTHING wrong with it. Many people expect a 24 year old console to have a BETTER picture with the Genesis on an LCD than the Genesis has with the CRT! If I have to put S-video on them to make sure they don't come back to me and waste my time, so be it.

I'm also looking for advice on how to add a chip to a KA2195D Genesis to bypass the encoder, perhaps with a CXA1145.

I'm assuming he's smart enough to turn up the sharpness on his tv if it has that feature.

Sharpness, what's that? You mean like the edges of the TV set? Should I file them down?

[evildragon]

Which displays a clean picture that picks up interference just as well as a flatscreen. I can't see any other reason why his tv doesn't pick it up other than it being sh#t. I'm assuming he's smart enough to turn up the sharpness on his tv if it has that feature.

Actually you'd be smart enough to turn DOWN the sharpness.

Sharpness does nothing but add edge enhancement, which is stupid.

[Majestic_Lizard]

Actually you'd be smart enough to turn DOWN the sharpness.

Sharpness does nothing but add edge enhancement, which is stupid.

It would also prevent me from injuring myself on the sharp edges of the television when I am walking around drunk in my home.

[evildragon]

Oh I know! There's nothing like being stabbed by a friggin pixel. They hurt when sharp.

[Majestic_Lizard]

It turns out the Master System issue only appears on LCDs. It does not appear on CRTs.

With the 220 ohms resistor there are no problems with Master System games on CRTs with S-Video. It is just with LCDs.

[jmazz88]

hey everyone
quick question for everyone. does anybody have or can point me in the directions of a sound circuit layout for gen2 VA1 board thanks

[francochan]

Interesting... on some mods, jailbars show up because of the newer HDTVs their playing on, and the settings these HDTV use in bumping sharpness. Never thought of that. Kind of like how oscillating/flickering 3D technology doesn't work for some people with bad eyes, or how plane propellers look strange on HD cameras; it's the higher tech that ruins lower tech fidelity.

On another note, I recently did a mod on my Genesis 2, using the same CXA1145M technique (c/o TheDamoMonster on YouTube). 220mf/16v capacitor for LUMA + CHROMA, 75 ohm resistor attached to both caps, and basically wired exactly as the video showed. However, besides minor jailbaring (which the above discussion has already shed light on), I'm experiencing these two problems:

1. Color Flicker - certain hues (red-orange, yellow, light blue) reverberating and "glowing". Almost like they flicker darker and lighter. Happens in Pinocchio's title screen and blue sky a lot. Other games also show it if they display these problematic colors.

2. Wrong Tones - I notice that some games have the reds displaying closer to fuchsia, and the blues displaying light violet. Strange. Contra Hard Corps colors are all wrong (title screen is basically fuchsia and violet), as is Castlevania Bloodlines (the light blue walls and large statue head is now closer to a turquoise color)

Any help on the above issue will be appreciated.

*for added info:

AC Adaptor - not original Sega, but a generic DC adaptor that I adjusted to give out 10V with center positive
Gold plated S-Video/RCA Cables
No capacitor changes - this was a unit I picked up at a junkshop for $7, with no guarantee of it working. So all the old capacitors have not been changed yet. Will this have something to do with it?

[MaxWar]

...220mf/16v capacitor

220mf!!! holy junk, that cap must be bigger than you console!

In all seriousness, I have not tried the specific mod you describe. I use the variant with a single amp on the luma and it works well for me.
Like this here ( note that the capacitor is reversed on the diagram )

[ApolloBoy]

I would suggest using a 220 or 330 ohm resistor for chroma instead of 75 or 82 ohms, as I got less of a jailbar effect with a higher resistance on the chroma signal. I think you can even use a 470 ohm resistor but I haven't tried it yet.

Also, I like to build my components onto the encoder itself; the base pin of the transistor can be soldered directly onto pin 16, and you can bend the collector pin onto pin 19 which makes it nice and rigid. The resistors can be soldered onto the S-video jack itself and covered with heat shrink.

On another note, I recently did a mod on my Genesis 2, using the same CXA1145M technique (c/o TheDamoMonster on YouTube). 220mf/16v capacitor for LUMA + CHROMA, 75 ohm resistor attached to both caps, and basically wired exactly as the video showed.

That particular mod is supposed to be for the CXA1645 or MB3514, not the CXA1145.