External DAC from Playstation 4309

[sorenj07]

A friend recently picked up a 1001 or 1002 which has the AKM AK4309AVM surface-mount chip. Unfortunately, the PSX was from eBay and did not work, but I believe that the audio channel should be all right. I am intrigued by the idea of building an external DAC around this chip, but was wondering what kind of stuff I'd need - an oscillator, certain voltages, etc.?? This mainboard has a 67.737 surface-mount oscillator as well.

I have looked at the schematic for the PSX's audio section here at ( http://dogbreath.de/PS1/output/output.html ) as well as the mods he discusses and am therefore quite familiar with the stereo end of the DAC, but what kind of inputs does it require? Certainly it can't be that complicated??

Here's my idea: Take pins 16 and 15, left and right and connect them to a 1uF Auricap and then to RCA output pins. It looks like pin 7 is +5V, pins 3, 19, 23 are ground, but what are the rest? Is there some simple way to use this as a DAC? Am I totally misguided?

Hopefully, with the PSX' popularity, someone has undertaken such a project but as of yet, I am eager to try.

[sorenj07]

I used a tried-and-true method to get the 4309AVM off the PSX mainboard: apply a slight upwards leverage on the chip with a razor and hold a lighter beneath the PCB until it just lifts off. I did the same for the CXD2510Q chip which I believe is a DSP.. not sure I'll use it in my DAC but it's nice to have. I junked the rest of the board.

Now, to compose a schematic to run the 4309...

[peufeu]

It's a 1-bit DAC (urgh) with a switched capacitor lowpass filter (argh).

Why would you want to polish a turd ?

[sorenj07]

wow. umm, because i have the chip on hand, and i thought the psx had good sound? sorry to offend you by posting some questions. and since when are 1-bit non-oversampling dac's bad??

[peufeu]

Umm, I happen to think that old 1-bit parts like this one suck ; all chip manufacturers seem to share the same opinion as they only market this kind of chip as a low-cost solution, and have advanced multibit sigma-delta chips for the "high-end" market segment.

Anyway, having some part lying around and wanting to tinker with it is a perfectly valid reason to experiment, so go ahead !

I was merely suggesting that if you spend, say 50 hours of your time on this project, maybe investing $10-20 on a better chip (pick one from BB, AD or Wolfson flagships) isn't that silly

And I do think there is too much turd polishing going around in the audio world : think CD723, CD63SE, SPDIF...

[sorenj07]

ouais mais je voulais depenser si peu d'argent que possible... ce projet etait presque une blague mais, si je deviens serieux, peux-tu suggerer un meilleur DAC chip? je suis toujours pret a ecouter les idees le TDA1541 c'est bon? sinon, ca serait drole de polir cette merde.

for those who only speak english, there is a google translation

ouais but I wanted to spend if little money that possible… this project was almost a joke but, if I become serious, can you suggest a better DAC chip? I am always ready A to listen to the ideas is the TDA1541 it good? if not, it would be funny to polish this turd.

[johnm]

Turd or not... the 1002 model Playstation with a few mods sounds as enjoyable to me as both my Naim CDI and Shanling CD-T80.... go figure :-)

John

[sorenj07]

well I have yet to fully figure out how to build my own clock for this sucker.. maybe I should talk to yeo from diyparadise, see what I can learn from his monica?

edit: or maybe i should just build his monica lol and save myself the trouble

[peufeu]

Héhé, je suis français aussi...

I suggest you build a SPDIF receiver on a separate little board with I2S outputs ; connect it to your DAC with a ribbon cable. This way you can re-use it on any other DAC project ; besides it's easier to debug : if you fail one of the two boards, you only get to re-do one.

[sorenj07]

yeah, I saw you were from Lyon. Anyway, I'm pretty new to the digital realm, but I assume that the board with I2S outputs would send a clock signal too? Does it "parse" the SPDIF input at all? Are we talking optical or with one RCA cable here for the digital input from the transport?