Before swapping amps please check following things also:Is your panels proper runnin in.They took lot of time to run in.Placement is also criticle and room treatment can cause sterile sound or un invoving.Your amp is very good and it might not getting the proper current etc.If things remain the same than go for tube.I use to have Martin Logan CLS for eight years and I used many amps on it ; Pass lab,Plinius,Mark levinson,Quad,CJ,Accuphase, etc.Each amp got strengths and weaknesses.Pass did a very good job with my panels.So did the CJ premier 11 and twelve.Before making any decissions first audition the short listed amp in your room and system thoroughly and then go for it.
Good Luck
AAK