I'd look into a stereo DAC rather than a pre/pro. The DACmagic is a very good unit for the money. There are better at higher costs, just like everything else IMO. Depends on your budget.
You can go from your cable box or TV into a 2 channel DAC if you have the option of PCM (I think that's what it's called) output. My cable box has a digital output option that's simply called "2 channel."
My TV and DVDs sound far better through my Rega DAC than analog into my integrated amp. My old Theta Cobalt DAC also sounded better than going analog into my integrated amp.
Whatever DAC you're contemplating, make sure you have enough inputs. Most TVs now have an optical output, making that effectively an digital switching device. Not all TVs' optical outputs will have a 2 channel option though, as far as I know.