I'm using my Creative X-Fi Titanium (Non-HD) as a DAC for the Magni. My Bifrost/Asgard 2 is occupying the soundcard's optical out. This way I can play both simultaneously.
The noise/interference does increase when I hook up the amp to the computer soundcard via 3.5mm to RCA, but I still get a small "UFO nosie" without any source at all plugged in to the Magni!
. The connection seems to amplify it.
To get maximum interference, I plug the amp in, and then I manipulate my headphone's cord to make theremin-like musical sounds. The rate of my breathing and whether or not I am inhaling or exhaling can ALSO change the pitch!
I think I've invented a new instrument.
My Sony receiver nor Asgard 2 have ever done this even when connected directly to my computer soundcard with no DAC in between. Also, all my headphones are dead silent with my other amps.