It is not only the tubes but also the transformers that need the warm-up. My Aric Audio pre and amp come to life regarding soundstage and 'air' after about 45 minutes.
I believe speakers also need a little warm-up time.
How long does it take your tube amp to warm up?
My tube amplifier has about 12 tubes and takes a couple hours for it to open up and sound really good and comfortable to listen to. Always wondered why it takes so long for a tube amplifier to warm up and what’s happening during this phase.
If I left it on for six or seven hours would it sound even better? I normally don’t leave it on for more than four or five hours.
How long does it take your amplifiers to warm up?