Tube amp warm up

All of the tube amps I've owned needed about 15 minutes to sound good. Is it getting better after that period? Perhaps, but I don't kill myself trying to notice any difference -- I just know it sounds good after 10-15 minutes. Solid state stuff takes a whole lot more time to warm up. I've fooled around with gear that sounds really disappointing until its been on for many hours if it has been off for some length of time. That is usually not a problem because the solid state stuff can be left on continuously.

Probably the capacitors needed to be "reformed" by use. That is the reason people slowly bring up voltage using a variac for equipment that has been sitting for years.

As the charge builds on the plates of the capacitor, they actually move a bit in relationship to one another. But, for something sitting around for a few months, that is not the issue.

Still, capacitors take a very long time to come up to song, some types and brands more than others. I know a designer who uses Blackgate brand capacitors, but has put in alternatives for customers who do not want to keep their amps powered up all the time. He told me that his amps sound thin and dry if the Blackgates are not kept charged all the time.

My amp has a lot of Blackgates in them, but I cannot see myself leaving the amp on all the time. For me, it is more a safety concern than life-of-tube issue -- the designer insists that the tubes will last longer being left on all the time rather than being subjected to harsh turn-on conditions.