Tutorial: Wiring up a cxa2075 video encoder into a console

The cxa2075 is in my opinion the best quality analog video encoder you can get for a console. This encoder works on most systems without much difficulty (except for the rgb nes / famicom which is a bit more complicated). The cxa2075 has a sharper s-video picture with better colour encoding than any other video encoder I've encountered (better than the cxa1645 and better than the encoder built into the snes jr.). To get the cxa2075 video encoder working here's what I did:

1: Find the cxa2075 datasheet in google

2: Build the cxa2075 ntsc internal trap application circuit

3: Find the pinout of the video encoder that's built into the console you want to add the cxa2075 to.

4: Locate the following pins for the video encoder that's built into your console: r input, g input, b input, xtal / oscillator / colour sub carrier input, and sync input

5: Solder wires to all the above pins once you locate them.

6: Wire the other end of those wires into the corrosponding inputs of your cxa2075 circuit

7: Wire up power and ground to your cxa2075 circuit

8: Wire up the s-video / rgb outputs of your cxa2075 circuit to a connector of your choice, you can even wire up composite video if you like terrible looking video

9: Turn the system on, if you wired it correctly you should have an amazingly beautiful picture, if not then you screwed up, check your connections / handywork

Of course the other option is to hire me to build and install this video encoder into your system, I'll install it into any model of the snes or sega genesis for 150$ plus the price of shipping your system to me and back. Just a warning though certain models of the sega genesis will have video jailbars and rainbow banding. I don't know how to get rid of the rainbow banding and I might have a fix for the jailbars but that's nothing certain.

Drakon, is it possible to wire up the cxa2075 to the existing video out of a comsole? E.g. The SNES. I really liked the quality improvement of your mod but have no desire to mutilate my case to add s-video.

snucker wrote:

Drakon, is it possible to wire up the cxa2075 to the existing video out of a comsole? E.g. The SNES. I really liked the quality improvement of your mod but have no desire to mutilate my case to add s-video.

That would lower the video quality, buy a dremel and learn artistic hole cutting?

If it's for the SNES, you could cut the Y/C traces going to the AV connector and run the CXA2075's output to them instead.

Thanks Grambo. I'll have to try that. My SNES already outputs s-video which is why I didn't want to dremel through it =)

last thing: im assuming i would want to build the Internal trap circuit. is that it?

Grambo wrote:

If it's for the SNES, you could cut the Y/C traces going to the AV connector and run the CXA2075's output to them instead.

I always try to do this. xacto knives work wonders. I much prefer using original connectors rather than adding some on.

wouldnt The best snes to do this to would be a 1-chip or jr, since they output a cleaner source?

how much of an improvement would it be to an old shvc console? I bought a super clean one by mistake, and it would be perfect for this mod. ive never seen an shvc before that wasnt yellow.

Ytrap is for composite video, I don't use it so I didn't wire it up.

Difference between the onechip ppu and the old style ppu outputs:



S-video comparisons. The mod isn't worth it on a system that doesn't have the onechip ppu.

[quote="Drakon"]Ytrap is for composite video, I don't use it so I didn't wire it up.

i dont understand. the datasheet lists a circuit for an internal ntsc trap and one for an external ntsc trap.
Wich one am i supposed to build?

also, is the pin thats marked SC on both the cxa2075 and the s-rgb for the clock signal? im not sure wich one is the clock.

and, ive seen that video before.

what id like to see is one with the cxa installed. do you have one?

mvsfan wrote:

and, ive seen that video before.

what id like to see is one with the cxa installed. do you have one?

That is one with the cxa installed. Like I said, ytrap is only used for composite video. Therefore, if you don't use composite video, you don't need to wire up ytrap.

Drakon wrote:

mvsfan wrote:

and, ive seen that video before.

what id like to see is one with the cxa installed. do you have one?

That is one with the cxa installed. Like I said, ytrap is only used for composite video. Therefore, if you don't use composite video, you don't need to wire up ytrap.

ah - so i dont need any trap circuit, its only for composite.

Thanks.

i just rewired my rgb nes today, and it made me think - are there any issues with picture quality caused by wire length on the snes like the nes has?

mvsfan wrote:

i just rewired my rgb nes today, and it made me think - are there any issues with picture quality caused by wire length on the snes like the nes has?

Nope. I can grab s-video from the encoder built into my snes mini or I can rewire it with extra wires to a cxa2075 both generate the same amount of interference which a tv mostly doesn't even pick up.