Which amp for the Proac 2.5s

"I have had the Proac 2.5 driven by the VAC PA 100/100 stereo amp and VAC Standard tube preampfor several years. It is a wonderful combination in many ways but I've come to realise there is something missing. Namely, the sound lacks punch, speed, and the impact I've heard on other systems. I also know that my Proacs are capable of delivering a more visceral base response than they presently do. I suspect this may be the result of insufficient power.
I generally prefer the musicality that tube electronics offer but would be willing to consider solid state if I were not giving up the tube like attributes.
I would also prefer not to mortgage the farm so I am not adverse to buying pre-owned equipment and would also prefer to stay with a stereo amp. I also may upgrade my speakers in the near future.
Recommendations would be much appreciated."