The Rega DAC is a very big step up IMO. I had the DACmagic in my system for a bit. Wasn't close. Others have disagreed. Can't really see why, but who am I to say they're wrong?
The other DACs mentioned should also be a good improvement. I like the Rega DAC the most, hence why I bought it. System synergy will make or break any component, including DACs.
The other DACs mentioned should also be a good improvement. I like the Rega DAC the most, hence why I bought it. System synergy will make or break any component, including DACs.