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

[Byron8805]

Thank you SO much, you've cleared up a lot for me and I think this thread will be valuable to anyone trying to do the saturn or dc mods right : ) Out of curiosity what type of bike are you building? I'm building an nsr right now which is popular in your neck of the woods no? Thanks again for the help, ordering my hex buffers now...

[brendanraymond]

sure, no problem.

I'll get you a photo of the back of the board in about 6 hours

I'm a fan of the nsr actually. Actually borrowing a few parts from the SP model such as the dry clutch and swing arm... also using forks from the honda rs250... so trick gear The bike I'm building is a cbr250, you can find my trails on the nsr forums and the cbr forums too.

i'll be back with picks

[brendanraymond]

Sorry, I swore I had pics of the reverse side of the board but I couldn't find them so I took a few new extra ones.








(you can see here I was over exsesive with the solder but it was fun
Also seems to be soaked with superglue so the finish doesn't look to pretty anymore.


blue wire is +5v and the white is signal, and the orange is ground. the signal wire is also shielded


these are the two resistors you see on my board. resistors are blue +/1% tolerance resistors




finished product

[SGGG2]

Okay. Lost as ever.

I ordered the same hex inverter chip, but I can't make sense of that breadboard. It really doesn't matter if I use it? I'm leaning on leaving it out...

[brendanraymond]

yeah, its bread boards are hard to make sense of the traces.

I'll see if i can draw up a schematic at lunch.

the hex inverter just needs 1 signal in, 1 signal out, +5v and Gnd. signal out of the buffer goes to the emph line

[brendanraymond]

pin 25 on the PCM1710 is a mute line. I'm guessing that the system mutes the chip briefly on startup so I can use them as reset lines.

On the model 2 boards with the PCM1710 all the necessary signals have corresponding test points on the bottom of the board! These are listed above. The mute line I'm using for reset doesn't have a test pint only a small via hole to hook up to. It may make sense to just tie the reset line high. I need to look at my model 2 board and see if the test points are the same.

Also don't forget to switch the word clock, bit clock and SDIN from the filter chip just in case there are bit count errors and needs to resend data... but it might not be an issue.

[SGGG2]

Is this the right hex inverter?

http://parts.digikey.com/1/parts/509322 ... 050be.html

[brendanraymond]

its a "not logic gate" so you'll be fine

just make sure you get the Vss and Vcc around the right way

[brendanraymond]

should I make a video showing the performance of the mod? I don't know if my mono mic camera will be able to pic up the difference but it sounds brilliant!

[Jamisonia]

so you ended up needing to buy that HEC inverter? The gamesx mod is wrong in this case, but they updated it for the DC apparently? What chip did you use?