I just want to respond to the gentlman above who thought the new class d amps sounded so "great", than all of a sudden found them unlistenable! VERY STRANGE! The Rogue and McCormack are VERY warm (colored) amplifiers. The newer class d amps are almost RULER FLAT! Class d keeps improving, so if I were you, I would keep trying them. Merrill Audio has terrific sounding class d amps. Also I would try the newer Purifi based amps (VTV and Rouge).
Initial impression of the Nuprime ST-10 amp
I have a very fine McCormack DNA .05 Deluxe amp, a Don Sachs 6SN7 preamp, driving my Spatial Audio M4 Turbo S open baffle speakers and today swapped the McCormack amp for the ST10 amp. Right out of the box, the ST10 is quite an amazing amp. It is very powerful and yet quite delicate in its rendering of sound. To my ears, it is somewhat tipped-up in the HF compared to the McCormack amp, and at this point seems to give up a bit of the LF rendering of the sound to the McCormack amp, but overall, it has lots of inner detail and a sublime mid-range. It has not a bit of harshness or dryness that I have heard with earlier Class D amps... it is very musical with the sound flowing effortlessly. I will post my impressions after it has been run-in for a week. My initial impression is that for $1600, this is a very fine amplifier.