I've never heard either preamp you listed, but I have an active Bel Canto PRe3, a customized passive Placette Audio Remote Volume Control, and both my DACs have a degree of volume attenuation. All sound great into my Reference 8.02, although I can see why a DAC-direct route might sound a little too transparent. The PRe3 adds density and even greater extension at the frequency extremes, and the Placette adds a smidgeon of midrange body. One of the great advantages of NuForce amps is that I can effectively ignore them when trying out my other components because they have very little character of their own.
Enjoy!