L-let's just have the picture speak for what this had wrought on my TV screen: I just tried this on my MB3514-encoded VA2.3 (which I had modified to use a 47uH coil on L2 and tweaked up the band-pass filter and delay line to get a sharper composite image), and. Other sites I've found related to the topic of this thread. It isn't quite as good as the CXA2075, however, which has less fringing and completely kills the vertical lines. Unfortunately, the vertical lines remain, but they're far more faint than on the KA2195D. Colors are better (especially reds, which look rather orangey on the KA2195D), picture is slightly brighter and has better contrast. Overall verdict? Much cleaner than the KA2195D. Add a voltage divider consisting of a 1Kohm resistor to Ground and 1.5Kohm resistor to 5V at L1 (this is VRef for the op-amps) then place a 10uF capacitor to Ground to filter the VRef Add a ceramic capacitor to C29 (value unknown, it was pulled from the VA2 Genesis 3's video circuit) and a 12uH inductor to 元 Replace R54 with a 47Kohm resistor and 0.1uF capacitor in parallel Add a 0.1uF capacitor to Ground on pin 9
You must use a small capacitor in series with an inductor of 12uH to get rid of this. If you leave pin 17 floating, the picture gets severe fringing. You must cut the trace splitting off pin 14 of the encoder and solder the resistors at the solder spot for L1. The CXA1645's VRef is EXTREMELY high, almost 4V, and will keep the Genesis in reset for a long time, if not forever.
You must make your own VRef with a 1.5Kohm resistor to VCC and 1Kohm resistor to Ground plus a 10uF filter capacitor.
47Kohm resistor and 0.1uF capacitor to Ground on pin 13ĪDDENDUM: There appears to be more required for the CXA1645 mod to work properly. The s-video from a Sony CXA1645 is simply gorgeous.įor more Sega Genesis model - 2 modding tutorials, please visit the following link below.Īfter having cross-referenced the application circuits in the CXA1645 and KA2195D datasheets, in order to use the CXA1645 in place of the KA2195D, you need to make sure of the following: Follow this diagram and make sure you have the 27 OHM and 2N3904 Transistor ready! It's honestly the SAME as the a model 1 Genesis. This guy is a little more complicated, but doable. This piece is of the tutorial is for the Sony CXA1145 encoder only. Also solder your 2 white cables for GND to the negative leg of a nearby 47uF CAP. Now end it by soldering your Chroma and Luma cables to the cables soldered to the (-) side of the Caps, remember Chroma is PIN 14 and Luma is PIN 15. (Now that I think about it, I've should have just long wired all of them like I did with GND, whoops!) Go and lock it in place to where you've drilled for it. Once you know those cables are for sure soldered in, hot glue them in as well. Now, take 4 small cable pieces and begin soldering them to the legs, use a knife or something sharp and place in the middle of the jack to make it easier on your eyes and prevent accidentally soldering the legs together. Take your s-video jack and add some solder to all 4 of it's leg, while having something holding the jack still as you do it. Half way done, Now we just need to solder the cables to our s-video jack, along with our GND, so let's begin with the jack from here. Next, solder them to PINS 15 and 16 of the Sony CXA1645. Let's get our resistors and caps soldered together first. Recommend getting GND again from a 47uF CAP, there usually near the chip. Now the Sony CXA1645 is WAY easier to mod for s-video. I will be just mentioning the CXA1645 from here on out This piece is of the tutorial is for the Sony CXA1645 & Fujitsu MB3514 encoders only, this mod works the same on both of them. Now go to the board and locate the video encoder, found behind, near the cartridge slot. Once you found the place that pleases you, drill in the hole but not too big. I'm working on a VA3 for this tutorial, so I'll be placing them on the side since the VA3 & 4 have a completely empty spot on the side. Mark the area on where you want to drill in for your jacks to be placed in. Next, before we work on the board itself. Ok first off, open up the system and remove all screws to the point where you're able to completely take off the board. 2N3904 Transistor (Or similar) <-(Only for CXA1145M) 27ohm 1/4 watt Resistor <-(Only for CXA1145M) Chassis Mount S-video Jack (You can get the gold ones I use or standard ones here.) You can find the same wires I used here,) Cables (Highly recommend 28 gauge cables for better handle. Not only is it consider the worst video encoder to find on your Model - 2 but it doesn't support s-video. The Sega Genesis model - 2 has the following video encoders, they can all be modded for s-video, EXCEPT the SAMSUNG KA2195D.