Mordante,
As a very general comment, I find that it takes FAR longer for solid state gear to warm up and sound its best. Most of the tube gear I've heard sounds decent in 10-15 minutes, some solid state stuff can take more than an hour to sound good. But, because it is more practical to leave solid state gear on all of the time, warm up issues can be avoided with solid state while it is almost NEVER a good idea to leave tube gear on for extended periods while not in use.
I am not familiar with Octave gear so I don't know about the particulars of your experience. I will say that there is a VAST difference between tube types and particular tube amp designs, and pretty significant differences between vintages and brands of any particular type of tube that one should not draw too many conclusions about the "sound" of tube gear based on limited exposure.
I know a lot of people demand power, and the KT120 and KT150 do deliver much more power than other tubes in that family, but, generally speaking, I much prefer something like the EL34 or 6L6 in pushpull amps. I find that there are a number of high-powered pushpull amps that, to me, sound much leaner (stripped of harmonic density and weight) and exhibit more "glare" (sharp prominence in the treble that creates a hard or shrill sound) than most top solid state amps.
It will be quite rewarding to hear a number of different amps. I don't know about the speakers you are driving, preferred listening level and size of your room, but, as a general caveat, don't overlook tube amps that deliver much less power than the solid state amps you are familiar with--you might be surprised how much less power you really "need" when the amp sounds right.
As a very general comment, I find that it takes FAR longer for solid state gear to warm up and sound its best. Most of the tube gear I've heard sounds decent in 10-15 minutes, some solid state stuff can take more than an hour to sound good. But, because it is more practical to leave solid state gear on all of the time, warm up issues can be avoided with solid state while it is almost NEVER a good idea to leave tube gear on for extended periods while not in use.
I am not familiar with Octave gear so I don't know about the particulars of your experience. I will say that there is a VAST difference between tube types and particular tube amp designs, and pretty significant differences between vintages and brands of any particular type of tube that one should not draw too many conclusions about the "sound" of tube gear based on limited exposure.
I know a lot of people demand power, and the KT120 and KT150 do deliver much more power than other tubes in that family, but, generally speaking, I much prefer something like the EL34 or 6L6 in pushpull amps. I find that there are a number of high-powered pushpull amps that, to me, sound much leaner (stripped of harmonic density and weight) and exhibit more "glare" (sharp prominence in the treble that creates a hard or shrill sound) than most top solid state amps.
It will be quite rewarding to hear a number of different amps. I don't know about the speakers you are driving, preferred listening level and size of your room, but, as a general caveat, don't overlook tube amps that deliver much less power than the solid state amps you are familiar with--you might be surprised how much less power you really "need" when the amp sounds right.