I ended up with these particular amps because I needed 5 monoblocks for my 5.1 system setup. My previous amps were Mark Levinson. I was fortunate to have them in my system on loan prior to buying them, so I had a chance to hear the amps "broken in". They are class D spec. I never thought I would own class D amplifier due to the stigma associated with them in the past. I will state for the record that these amps sound fantastic. The low end bass is deep and powerful and best of all tight. Regarding the midrange, it is silky smooth and natural sounding, they really emphasize well recorded vocals both male and female. The high end seems to extend forever but with detail and quickness I had been missing in my past configuration. Never bright or edgy. They eerie part is the silence I hear in the background. The great thing is they run much cooler so the room stays pleasant. The specifications and the review of the Theta Prometheus monoblocks.