"Best" DAC for a grand or less

I am looking for a DAC for under a grand . I want something to favor the bass side ,as now my system is a bit on the bright side.I would like it to have a usb port also.My system now is......
Hafler pre amp
Counterpoint solid 1a amp (100 watts)
Nad 515 cd player
Tekton Lore speakers
Thanks.