*Update2* SPDIF Audio mod Sega Saturn with *ahem* big pics

[brendanraymond]

Sorry I've been so quiet this year guys... trying to get ready to move overseas and have 1000 things i need to do...

I did however bother to upload a vid of its performance... though unfortunately the mic on my camera doesn't do it any justice. The sound quality is perfect... and when its quiet... its really quiet. no background hiss what so ever.
11 speakers of goodness!

I loled when the subwoofer went off... sounds terrible in the video haha

http://www.youtube.com/watch?v=BEKLsyjYrbQ

[brendanraymond]

So has anyone actually done this mod yet?

[Konsolkongen]

Hi. I will try this when I receive my This is COOL Saturn from Solarisjapan

I'll be using toslink cables so I bought this transmitter:

http://www.ebay.com/itm/Toslink-Transmi ... 0651676526

So I just solder it up like this?

Pin 1: GND
Pin 2: 5V
Pin 3: TXP from CS8406

I don't understand why you lifted the pins on the TDA1386T? It doesn't say that it's needed anywhere on the GamesX page.

I obviously don't know what kind of audio chip my Saturn has but it's good to know that the TDA1386T requires the HEX inverter at least. I assume a 7404 will work fine if needed?

[Konsolkongen]

I got this up and running with toslink cables on a Japanese VA13 Saturn. The DAC is a newer type than the ones mentioned on GamesX, but since it shared the same "TP"-points on the bottom of the motherboard it was fairly simple to figure out.
No inverter needed for this model

I only took very few pictures of the process, but I will try to draw up something that explains in detail how to perform this mod on a VA13 Saturn. It won't happen 'till after Christmas though :/

In the meantime:
http://i40.photobucket.com/albums/e236/ ... IM0255.jpg
http://i40.photobucket.com/albums/e236/ ... C00105.jpg

[brendanraymond]

Wow you did a very neat job. I like where you placed the toslink led transmitter... I should put mine there too

Sorry for the late reply, but I've been abit sick. But in regards to lifting the pins (not stated on that website I linked) is because one of the three data wires is bidirectional, and I think this is for checksum or something... so to avoid any interfearance I wired them to a switch so that only one DAC would be connected at one time. I was just being over cautious... it probably works fine with them both connected anyway.

Also, do you know much about modifying xrgb3?

[Konsolkongen]

Lol, it was just a test to see if it worked before I started cutting in the skeleton case For region I have installed a new Bios and 50/60Hz is done with the reset button.

Here are a few more pics I took the day after, when I made the hole for the toslink transmitter. I think it turned out pretty good:
http://i40.photobucket.com/albums/e236/ ... IM0256.jpg
http://i40.photobucket.com/albums/e236/ ... IM0259.jpg

As for lifting the pins, I understand why you did it, but the DAC in mine is so incredibly small and lifting the tiny pins would be almost impossible. Thankfully the analog audio sounds the same after doing this mod.

What mods on the XRGB-3 are you thinking about? I have modified the RGB (GAME-IN) input on mine to use EU Scart cables rather than the Japanese RGB21 standard. I added 3 220uF caps on the D1 (component) input in the back to remove most of the noise in the PS2's component video signal.
I also replaced the Panasonic video splitter chip when it died in mine (no video ), but I wouldn't recommend that unless yours is dead

[brendanraymond]

I'd give you a 10/10 for neatness!

As for the xrgb, I've been having trouble trying to standardise all of my rgb signals from my consoles. From memory (about 6 months ago) I was using the vga port on the back as it takes 15khz rgb... but the pain in the butt issue is that on some consoles, composit video works well for sync, and some some consols have to use the standard sync line... but they seem abit noisy or something... so I was wondering how to work out how to put caps on the rgbs lines or build sync splitters etc... I'm not really sure exactly is the problem as every console is differrent.

[Konsolkongen]

I use c.sync on all my consoles (Saturn, MegaDrive 1 and SNES) since it's my experience that you might get dropouts every now and then, if you use composite video as sync, especially when the screen flashes white.

I did have some trouble using c.sync on this VA13 Saturn. For some reason this was what it looked like when I connected it to either the XRGB-3 or TV directly:


After a bit of experimenting various solutions I found that all that was needed was a 220uF capacitor on the c.sync line. Now it looks great

But about the noise. Are you using LPF? If I turn OFF LPF when using this particular Saturn I get horrible "jailbars" in the picture, and if I have it ON it looks fine. Do you also get noise when using the GAME-IN port in front? The first RGB to VGA cable I made wasn't grounded properly so I got a bit of noise when using the VGA port in the back too. The one I'm using now looks every bit as good as the GAME-IN.

I don't think you need a sync splitter when using c.sync. If your console only does composite video as sync then using a sync splitter might cure the occasional dropouts.
I haven't used a sync splitter in a long time, but when I did use composite video on my MegaDrive it worked pretty well. I build one myself using this information:
http://www.gamesx.com/misctech/lm1881.htm

Alternatively you could buy a Sync Strike from here:
http://wp1114205.wp150.webpack.hosteuro ... ucts_id=15

I don't know if it does anything different from the one you can build yourself, but besides the sync splitter feature it would serve well as a RGB to VGA adapter for your XRGB-3. Just keep in mind that this is wired to the European SCART standard.

[SGGG2]

That pic looks familiar.

What size caps did you get? I ordered some off ebay and they were way too big.

[Konsolkongen]

Haha, hope you don't mind

220uF.

I have since then compared schematics from the VA0.5 and VA13 Saturn. Of course many things differ, but video out part was somewhat identical, and on the VA13 it lacks a 75ohm resistor and 220uF cap. Seems like the 220uF cap is good enough on it's own though.