Well, it isn't that I don't like the amp, but would like perhaps a bit more transparency, bit deeper soundstage, more of an in-the-room feel, deeper, tighter bass, better frequency extension, and a bit more power for complex passages would be nice. I figure that a better amp could do all of these just as well: I am sure that the Cayin, as nice as it is, probably isn't as good as some of the ones listed above. But, not really having had such an amp in my system, I can't say for sure. I am not experienced enough to say what sound I am shooting for; I just want it to sound like a live show, as difficult as that is.
Stock KT88's and upgraded Electro-harmonix rectifier tubes are what I am using now. Do you feel that tubes could get me part way there?