I use vmix to do 2 things: play out my pre-roll videos and ads, and graphic overlays.

Hardware switcher (Panasonic)
and an AJA Kona card for video I/O.
PC HPZ600 server running Win 7 computer uses a SoundBlaster Audigy card with 1/4" outputs.

My audio mixer is analog, and recently I have started to get a loud hum on the audio output by the computer.
I mix this into the mixer with a 1/4" to XLR adapter.


So my chain is as follows:

Vmix plays file with audio out on 1/4" from soundcard into mixer. Mixer outputs to a rackmounted encoder on XLR input, video on HDMI. I use the HDMI port on my NVidia card to send video stream to an AJA distro amp, which then feeds rackmount unit, onsite monitors, etc.

Steps I have tried:
Replaced the 1/4" to XLR adapter.
Upgraded audio card drivers.
Put a ground lifter on the power supply to computer. (we travel, so power is always different by location)

I would like a better solution to actually play out the ads, or a better audio solution. In an ideal world would love to send audio and video out on SDI.
Any suggestions? My live hosts are on an analog mixer which then comes back to the truck mixer, also analog. The only digital audio is what comes out of the computer.

Thanks in advance

Its this one.
http://ixbtlabs.com/news.html?01/17/32

Used it for 3 years to send beautiful live audio only streams for internet radio. Sounds like a million bucks. Until well, it doesn't.

Onboard did not work, it doesn't recognize the adapter out signal.

I have not tried USB - can you make a suggestion for a USB - analog interface?

TIA