Philippe,

Looking at the level of your components and gear, you should try a Blue Circle Audio USB Thingee Digital Converter. It comes in several configurations:

Here is a writeup about it here: http://www.goodsound.com/equipment/blue_circle_usb_thingee.htm

I have several Blue Circle products and they are extremely high quality.

SC-05, HLT6189, Oppo BDP-93, Blue Circle Audio FX2
Axiom M2v3's, QS8v3's