Any Pass Labs amp would be terrific. A friend of mine had Sophia 1 and now has Sophia 2. By far, the best amp was the Pass Labs - he had both the X150.5 and X250.5 (presently utilized) and they were equally good (and terrific). They both surpassed an old Krell (don't know the model) and a very large recent Plinius. The Pass amps just had more of everything - detail, transparency, dynamics, bass, and a very nice sweetness also.
FWIW, I also have had great success with my recently obtained Pass Labs X150.5 for use with my Magnepan 3.6's. My system took a great leap forward with the Pass.
FWIW, I also have had great success with my recently obtained Pass Labs X150.5 for use with my Magnepan 3.6's. My system took a great leap forward with the Pass.