Thank you Sokratis,
I tested everything.
I have version 4.1b
The SPDIF is not working, but the SPDIF MAIN is working.
Note that the sliders does not control anything. But it's better.

I put the Audya sound card volume to the max (63) and the General EQ and WAV EQ to FLAT

To my hear, The SPDIF output sounds a little better than the analog ones ! More defined and mode spaced.

So I will probably record my wav tracks at 48Khz/16Bits

What do you think about it?

Dan