I am currently demoing a Rogue Audio Cronus Magnum II integrated. I am noticing the same thing I did when I used my PrimaLuna Dialogue Premium with the Adagios. There is a bit of grain somewhere in the treble that these speakers seem to emphasize. Overall, the Pass is clearly the better amplifier, but the rogue is more forgiving of poor recordings. But not all is good; for example, the higher octaves of stringed instruments sounds rather strident and aggressive through the Rogue, whereas on the Pass they are presented very well.
At this point since I am using two different amplifiers and neither of them seem to fit the bill totally for these speakers, I think I should take that as a sign that the speakers need to go. I think my ears may just have an issue with ribbon tweeters. I had this same problem with my previous speakers, the Golden Ear Triton Three. I am probably better off with something that implements a smooth treble using a silk dome tweeter. It seems harder to find speakers that are voiced more towards a musical sound rather than analytical, since "more detail" is probably what sells.