Better sounding after 1 hour

I noticed that after 1 hour my Cayin A-50T tube integrated amplifier sounds more open and dynamic. Is this a particular characteristic of tube amps?
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I would agree with Elizabeth but also slightly disagree I think this effect is more noticeable with tubes after about 30-60 mins. At least it has been and continues to be with my gear and gear I have owned previously.
I wouldn't leave tube gears on 24/7. This will shorten their life. Solid state, especially preamp, can be left on 24/7. Yes, most audio equipment sounds better after some warm up.
Tube electronics changes more quickly than solid state making tube warm up more obvious. I have owned tube electronics that warmed up in an hour and solid state electronics that has taken as long as 3 days.
Years ago when I got my Rogue Cronus Magnum, I couldn't wait more than 15 minutes for it to warm up the first time i used it. We started spinning tunes and it was mediocre at best. About 10 minutes later it opened up to the point I was practically in tears. I can't imagine what it's like for these people with much higher end gear. Yes, tubes do that.