Sound Card Crashing System

[DocFrogburn]

I have a very strange problem - my sound card, an Asus Xonar DGX, is crashing my system. 

Card in, system boots, runs smoothly for ~15 seconds, then the output freezes and after a minute or two the system shuts down.

Card out, the system runs fine.

Now, this started about an hour ago - I heard a pop in my headphones, then a continuous hissing and crackling. I confirmed that it was not my headset dying by testing it on my phone and the sound was fine. I shut down the system and removed the card, and then installed the on-board audio drivers so I could still use my headset.

Here's another issue I've been having - while plugged into my motherboard audio, my headset makes a clicking noise every few seconds and the audio is horribly distorted. My headset is an Audio Technica A900X, and its impedance isn't very high, so my on-board audio shouldn't have issues powering it.

I recently upgraded my gpu to a GTX 970, but I don't see why that would cause issues with my sound card.

Any help would be appreciated.

[DocFrogburn]

For the time being, I seem to have fixed it. I went into my bios and disabled my onboard audio, and uninstalled both the onboard audio drivers and the drivers for my sound card, then put the card back in and reinstalled the drivers.