Motherboard SDIF Output Or Soundcard

At the moment I too use my computer as a source. I felt it best to avoid the sound card altogether and output via USB.  

+1 gdhal.
I, too use either USB or Spdif and output to a Schiit DAC.
One upgrade it did recently was to get Fidelizer Pro. It really made the sound reproduction much better.
Bob

As with gdhal and gdnrbob, I also use USB. I would consider the purchase of a used M2Tech USB to SPDIF converter which plugs directly into the USB port and run coax to the V90. No USB cable needed. This opens the possibility of purchasing a older used DAC having a more robust power supply and analog output stage as a further upgrade. 

Great suggestions guys. I want to one day own a NAD m51. There was one used on eBay for half the retail price not too long ago. But I was a bit too skeptical about purchasing something so expensive used. 

In the mean time the v90 is a little gem. The sound I'm getting is excellent. Especially with modern day recordings. Although it does seem to lack a bit in the older recordings department. It's missing what vynl has to offer, warmthness and richness. But hey that's what my turntable is for, for all the old recordings. 

I think you should try a Schiit DAC. They have a trial period, so all you would be out is shipping costs. Great performance at a low price point.
If you do, I would love to hear what you think.
Bob