Van Monkey Islander:


Hi Strongeros,
this is the solution for SPDIF.
The interface that I built up did work for 15min. then it stopped working,
if I powered off the strong for a while, it did work again.
I though it was a problem with SPDIF and added the TOSLINK, but the problem
did still exist, so I went on with my analysis and removed C6, now it works!
I'm going to explain how to fix the circuit to use both TOSLINK and SPDIF.

Technical details:
let's start with the schematic:
http://www.investigacionludica.tv/f...ead.php?t=43880
There's a mistake in the schematic, and it's related to pin 20 of CS8402.
According to the datasheet, the ABSOLUTE MAXIMUM VALUE for any output
pin is 10mA.
If you look at the schematic, there's a network built up
with C6, R3 and R4; since the circuit works AC, C6 has zero impedance, thus
the load for pin 20 is 490ohm. The output current is therefore 5V/490ohm = 10mA, that is too much!
Recommended value for output current is below 5mA!

The solution is to avoid overloading the CS8402, this is possible in the following way:
a) remove C6 from the circuit
b) take a new IC 74HCT125 (any buffer is good, this was the one I had)
c) connect the HCT125 as follows: 
pin 1,4,5,7,9,10,12,13 -> GND 
pin 14 -> +5V
pin 2 -> to pin 20 of CS8402
pin 3 -> to R3 where it was previously connected to C6
d) disconnect J2
e) connect C6 between J2 and the connection of R3 and R4

Now you can plug your SPDIF cable and listen to very high fidelity music!

Last, but not the least, I used a TOTX178a TOSLINK, you can find it as a spare part for Pioneer or Onkyo.

I hope BIOSUPDATE to read this message and fix the schematic according to it.

Hasta pronto,
/Monkey