Super NES S/PDIF mod part request

Started by zedrein, November 14, 2010, 03:30:13 AM

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zedrein

(Yes, I am aware that certain threads are to be relegated to certain inferior channels *cough*, audio mods, *cough* but as there is typically a greater concentration of smart people located here on the main forum and as this is technically a part request and not a page detailing the mod, methinks justification is had)

As of November 13, 2010 10:30 am I cannot find a DSP chip that will reformat all the raw digital audio of the SNES' sound chip into something a commercial receiver can decode and amplify (and, yes, my new AVR can receive non-standard sampling rates in case you were wondering). The original document that detailed this mod said to use Cirrus Logic's CS8405A-CS, but that chip is no longer manufactured and the new version, CS8415A, cannot purchased for under $13 US unless you are buying in quantities of more than 1,000!!! I clicked on the "request a sample" link on Cirrus Logic's own site and (when the page actually loads) it prompts me to enter a legitimate business e-mail account which I am not in possession of. DigiKey, Avnet, and Newark are all sites that supposedly carry this chip, but not without the strings attached that I already mentioned...please help me in finding a comparable alternative or a resource where I can find this IC inexpensively.

Endymion


zedrein

Thank you for the link, but I'm still surprised that this IC seems quite expensive, $12.09 w/o shipping?! I thought something like this could be had for considerably cheaper! Thank you again, though.

duo_r

No pin mount version of this chip I assume?

zedrein

Well I'm afraid I don't know exactly what you mean when you say "pin-mount". You see, I am what you might call 'electronically challenged' so I don't know much of the nomenclature...yet. I am wading through my copy of Electronics For Dummies and getting a better handle on this stuff in the process.   

Since my first post more than a month ago I've found an inexpensive digital audio transmitter chip, but I'd like to know if the same signals I needed to tap for the original mod are still going to be the same for this chip. I am one of those guys that wants not only to know which of the pins I am going to be mating from IC to IC but what their function is so I don't have to continue asking such base questions as these:) I hyperlink'd the original mod already in my first post so here is the link to the new IC if you want to investigate for yourself. Thanks for keeping my thread alive, sir!

Hojo_Norem

The chip you liked would do the job but unfortunately its a 3.3v part and the snes works on 5v internally.  I think it could be made to work but that involves a level of electronic mysticism I don't know.  (I think it has something to do with voltage dividers).  You might end up using more extra parts the resulting cost may close in on the cost of the other ICs.

More detail:

I think the data signals can be brought down to 3.3v using resistor voltage dividers but the theory escapes me ATM plus you will need a 3.3v regulator to power the IC.  That would run off the snes's 5v supply without problem but it all adds up to cost and complexity.
Formerly 'butter_pat_head'

zedrein

I actually noticed the required 3.3 V power supply as well, how annoying! It looks like I'll just have to pony up the 13 or so US dollars and just go with Cirrus Logic's alternative, the CS8415A.

duo_r

wouldn't a resistor do the trick? I use that to step down 5V for LED's all the time. Just need the right resistor (like 10 cent part) and done. 

Hojo_Norem

Quote from: duo_r on December 14, 2010, 03:20:00 PM
wouldn't a resistor do the trick? I use that to step down 5V for LED's all the time. Just need the right resistor (like 10 cent part) and done. 

Resistors work with LEDs and such because the current required is fairly constant and LEDs and such can tolerate fluctuations in supply voltage while operating.  ICs on the other hand need a stable supply voltage to operate correctly and a simple resistor voltage divider won't usually cut it.
Formerly 'butter_pat_head'

zedrein

Thank you, Mr. Pat Head, unfortunately all roads lead back to me spending $13+ for one little IC.

duo_r

What is the tolerance on the3.3 part, maybe it can handle 5v.