not as much as replacing your preamp w/a tubed unit! ;~)
if ya still insist on getting a dac, i suggest the ~$130 art di/o, & then spend ~$100 tweaking it. i know of one person who is selling his belcanto dac cuz of the di/o, & several folks are selling far more costly dacs, now that they're using the di/o.
as for me, my modded di/o has taken my digital to the next level - something a $1800 alchemist nexus cd player or a $3k resolution audio cd-50 couldn't do. do a search on the audio asylum's digital forum, where the di/o praise has been beaten to death! ;~)
doug s.