How long can preamp tubes last?


Good evening Ladies and Gents
Trying to learn! I have had a Shiit Freya + preamp for about 1 year now, and it has about 450 hours of play time, with original tubes.
Is it time to change the tubs? What tubes/brand would be recommended to purchase? 
As far as budget, I really have no idea what they cost.
Also, what does the expression" rolling the tubes" means?

Any information would be welcome.
Thank for reading.
rockanroller

Showing 1 response by mglik

It depends on the preamp.
I turn my Atma-Sphere MP-1 off and on twice a day to save the 18 tubes. Ralph says that if left on, the tubes need changing every 6 months. I try to make them last a year or more. It is on about 8 hours a day.
I think that most preamps are easy on their tubes and can last many thousands of hours.