Parasound JC1+ warm up time

Leave it on. 

Not a JC1+, but I find my JC5 sounds good on first start but is in its prime after 30 minutes of warm up.

I also own a pair of JC1+, I bought them new! They did take approx 1000h at my home (230Volts) before really open up! But they do change quite profound when left on for several days! I work shift beeing away from home, but I do plan my critical listening session from how much time JC1+ has. Bare in mind these do get hot, but Im living in colder north so its not that much hassle for me most part of the year. I run them with a ARC ref6se and a Lumin X1 and the sound is just breathtaking. Som much amplification for the money even tho they are quite expensive these days.

I never turn my SS kit off. And even at that the system definitely sounds better after ~ 30 minutes if play

SS amps sound best if left powered up. A high powered amp like yours will never be at its best with only 30 minutes warmup. Big SS amps take hours to reach optimal performance, IME. Sure, you can start listening right away and SQ will continue to improve.

As far as Class A bias goes, I would think if it's at 10W at idle, then it's ready to go to 25W Class A.

Leave it on all the time unless tubes. That’s my motto.