As I understand, a tube buffer/preamp will addup/spice some sonic flavorings to ur setup, especially with the addition of what they say as even order harmonics to ur current digital set-up, rich in odd order harmonics.
As they say, these even harmonics is synonymous to what makes it 'tube-sounding'.. Other than that, a buffer could act as a possible impedance matching correction/interface.
Mr Owediah, i think there is no harm in trying with that kind of your set-up.
Finally, your hi fi ears will decide...
Tsaka, sayang kung hindi naman magamit....benta mo na lang sa min
'Real Audio, Glows In the Dark'....daw