#1
Let's say I play for 30-45 mins, every second or third day. How long do you think my tubes will last?
#2
You won't have to replace them for a couple years if you play at that rate.

*Edit: It also depends on how loud you play. If you have the amp cranked then the tubes will wear out faster than they would if you were playing at whisper volumes.
#3
okay, thanks. The reason is I'm considering whether or not to buy a tube amp, and the price of replacing tubes, and how often you have to do it is a determining factor.