I used to own a pair of D38's ... and I ran them with (wait for it) ... Cary CAD-805AE monoblocks. These have 50W of power. So is 50W enough? If most of your listening is simple stuff (like female vocals or violin solos) at low volume, 50W is ample. However, if your taste wanders towards large scale music (like Wagner) you will find that the bottom end is a bit lacking and the amplifier regularly runs out of oomph.
I thought the combination was absolutely magical for some types of music, but my dissatisfaction with the inability to project size and scale led me down another path.