How long does it take your tube amp to warm up?

About 45-60 minutes for VAC Avatar SE, but you can listen to it after 10-15 minutes.

I don’t have any reliable way to determine how long it takes for the system’ to sound its best.  It sounds good enough to enjoy within 20 seconds or so, and pretty much like it always sounds within s couple of minutes.

From my experience, it doesn't matter how long you let the tubes warm up. The amp won't sound its best until after 15 minutes of signal has passed through it. Ten minutes of idle is all it takes for a KT150 (the highest power dissipating tube out there) to reach operating temps, so I assume all other tubes require less. You're just killing tubes by letting them idle for hours before playing.

30 minutes...and 30 minutes to warm up and expand the voice coils in your speakers...... after 30 minutes of Playing, you should have the optimum sound that your system will produce.

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