Can I use an AMP/DAC with my Sound Card?

[AbedFa]

So I have an Asus Xonar DSX 7.1 Surround Sound Card that I've been using for long enough for gaming, and recently I decided to buy an FiiO E10k after reading all about it.
 
What I'm worried about is whether I can run it without having to uninstall this sound card. Recently I tried using a USB Headset but it didn't work out. The PnP Sound Device doesn't take over the dedicated sound card and the sound would still come out of my speakers normally, even though my windows detects and install the drivers just fine. Even after changing all different kind of Analog Out options in the Xonar Audio Center software.
 
Since the FiiO E10k is a USB device it had me worried and I'm glad I thought of this before ordering it. Any thoughts?

 

[MindsMirror]

You don't need to uninstall the sound card. You can use the USB DAC or headset by changing the default playback device in the windows sound control panel. If you do, it will bypass any features of the sound card. To use a sound card's features with an external DAC, it would need to be connected with S/PDIF, which I don't think is an option on your card. You could use an external amp while still using your sound card's features and DAC.

 

[PurpleAngel]

  So I have an Asus Xonar DSX 7.1 Surround Sound Card that I've been using for long enough for gaming, and recently I decided to buy an FiiO E10k after reading all about it.
 
What I'm worried about is whether I can run it without having to uninstall this sound card. Recently I tried using a USB Headset but it didn't work out. The PnP Sound Device doesn't take over the dedicated sound card and the sound would still come out of my speakers normally, even though my windows detects and install the drivers just fine. Even after changing all different kind of Analog Out options in the Xonar Audio Center software.
 
Since the FiiO E10k is a USB device it had me worried and I'm glad I thought of this before ordering it. Any thoughts?

 
Hopefully you disabled the motherboard's on-board audio, in the BIOS, when you installed the Xonar DSX.
 
Normally when you plug a USB audio device (E10K) into a Win PC (and Mac?), the sound card (DSX) is bypassed, and the USB audio device becomes the default audio device.

 

[ProtegeManiac]

In addition to what PurpleAngel posted, if you were using DSP effects off the soundcard's DSP chip - like virtual surround processing for headphones - it will not work with an added USB DAC as the computer will completely bypass the soundcard.