Somewhere, some how, some way the digital signal from your computer must go through a DAC to play on your stereo.... it's just a matter of where it is.
If you use the analog outs of your computer, you are using the computers DAC, if you ran analog outs of say an Apple Airport Express, you'd be using the DAC in it... see what I mean?? As for sound quality, when done right, it is very good, and there are many who argue better than high end transports as there is less jitter.
BTW Which Infinite Slpe speakers do you have?? I still have a pair of JSE IS 1.0's and 1.8's....