I had a Plinius SA-100 Mk III which I sold almost two years ago. There are things I loved about the Plinius and others which I felt clearly prevented me from classifying it among the best. I loved the midrange. In my system, I never heard a cleaner, more distortion free sound than that. Talk about seeing the world for the first time through a clean window! The upper mids might be a little bright, but that never bothered me. It added a little life and air to certain instruments and vocals, even if it wasn't absolutely neutral. It had outrageous bass slam and dynamics like few amps that I have heard. On the down side, despite the slam, the bass wasn't as deep as it should be. A top solid state amp should go lower than the Plinius. On the other end of the spectrum, highs are a little rolled off. Detail and soundstage reproduction are just a couple of notches below the highest level. Despite the negatives, I would say that taken in total, it gives a lot of sound for the money and the whole is greater than the sum of the parts. Your initial emotional reaction to this amp tends to be very positive before you try to analytically pick apart its sound to find individually what is there and what is not. Even today, as a very happy Pass Aleph 4 owner, which I feel is a significantly better amp, there is a lot I miss about my old Plinius. I would say that if you are auditioning tube preamps to go with the Plinius, you should definitely listen to the CAT SL-1 Ultimate with the Plinius. Those two had TREMENDOUS synergy. I recently A/B'ed the CAT Ultimate and the Conrad Johnson 16LS in an audition. IMO, the CAT blew away the CJ. In that audition, we were using a VAC Renaissance tube amp, not a Plinius.