I have a Theta basic II DAC. I tried M-Audio Sonica USB sound card and it sounds not so good compare to Theta Data II. I only have limited budget now, so I plan to put a DIP between DAC and sound card. I wonder if anyone has tried this kind of setup. Thanks.
Why put more money into mediocre components? Save your money and get rid of the Sonica and get a good converter and DAC. You might also consider modding the Theta. I recently modded an old Theta and it was amazing sounding.