I have the wadia 521 with greatnorthen sound co mods and it a very good dac. I read the review that robert harley wrote and he does say that the berkeley is the best dac he has ever listen to. He even bought the review model so i guess he really liked it. The wadia and the berkeley both have volume control but the berkeley can do hi-rez. I don't think you can go wrong with either dacs.
