External amplifier with sound card?

[fast2please]

Hi. After I have upgraded my sound system to passive speakers - Q acoustics concept 20 with PM6006 as amp - I decided I could use another DAC for my sound system instead of Creative soundblaster Z.

So I got myself ASUS XONAR Essence STX II. So here's the question

After reading manual of my amp thoroughly, I found out there is an DAC inside my amplifier. Something called CS4398. So is it a complete waste of money to set up like this? Soundcard -> AMP -> Speakers. I wonder if I connect coaxial line from sound card to amplifier, which DAC works. Both can't work, right?

 

[insider9]

That's correct. Only one will work.

If you're going to send the signal to from your pc to amp via optical calble the dac built into the amp will do the conversion. If you will use an analogue cable such as RCA from Xonar to amp, then the conversion from digital to analogue will be done by your sound card. There will not be any point sending digital signal from your sound card to amp as your onboard soundcard would send exactly the same signal.

Not all is lost though. The fact you have 2 decent quality dacs isn't something you should regret. My advice would be to compare and chose the one which sounds best to your ears. They are likely to have different sound signatures and you may prefer one over the other. DAC chip used in the Xonar is PCM1792, that's used for instance in Arcam irDAC so it's a very capable dac.