As I said above, I use a Pass X-150 with my Proacs, sometimes with a First Sound and sometimes with a Placette. I also have a CJ 11a amp that I play with from time to time. It has wonderful bloom and a huge sound stage, but I always return to the Pass. Ultimately, the CJ sounds rolled on top, slightly muddy (cloudy might be a better word) and the Pass gives me focus and clarity and resolution, which is what I hear in live music. It's a bit "buttoned down" compared to the CJ, but I can live with that. For the life of me, based on what I've tried in my system, I can't understand all the unbridled enthusiasm everyone has for tube amps.