The reason tube amps are still around all these decades on is that they make less audible distortion than transistor amps- the brightness of solid state is caused by distortion (and is as much a coloration as anything tubes do); this is why a solid state amp and a tube amp can measure flat on the test bench but the solid state amp will sound bright and the tube amp will not.I dont have much experience with tubes amplifier versus S.S. amplifier.... I only own a modest tube amplifier garage 1217 the Ember...And playing tubes was fun fpr some months... :)
But i can assure you that not all S.S. amplifier are made equal....
The qualities associated in all thread to tube amplifier, i feel them with my Sansui AU 7700 with no loss in bass control....
The Sansui is warm and detailed with great bass..... It is a so good amplifier i purchase another one.... :)