my Accuphase pre takes ~30 hours warmup to sound its' best. The amp seems less sensitive to sonic changes as it warms up, however I leave both pieces powered on full time (as for all solid state). Tubes I do not leave on full time, unless a standby setting is available on the component.
Realize that depending on your geographic location, you are more vulnerable to component lightning damage during a thunderstorm when equipment is powered on; however you do remain vulnerable even when powered off as long as the line cords are plugged in. So use a line conditioner with integral surge protection; alternatively install a whole-house surge protector wired parallel at the distribution panel, along with downstream parallel transient snubbers wired across your AC outlets, or built into them. Still: when storms are in your area the best protection is to power down and unplug everything.
Realize that depending on your geographic location, you are more vulnerable to component lightning damage during a thunderstorm when equipment is powered on; however you do remain vulnerable even when powered off as long as the line cords are plugged in. So use a line conditioner with integral surge protection; alternatively install a whole-house surge protector wired parallel at the distribution panel, along with downstream parallel transient snubbers wired across your AC outlets, or built into them. Still: when storms are in your area the best protection is to power down and unplug everything.