As usual, opinions are like buttholes. I may as well share mine. I owned and sold several pass labs amps of recent design. Why? I did not like the sound, period. This includes both class A, AB, monoblocks, and stereo .8s. For lack of a better description of what I didn't like about them I felt they were lacking in detail and seemed a little fatiguing at times. I finally brought in a new Luxman 509Z. It is the best amp I ever owned. Sounds amazing to my ears.