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?


By the time I have my first drink, my amp and I are both warmed sufficiently.

It sounds good after a few minutes. But most tube amps do. About 45 minutes to an hour and it sounds optimum.

My amps are SETs and a very simple low parts circuit and sound good right out of the box. It's possible they start to sound better after 30 mins or so but wouldn't want to bet my life on it.