how offten do you have to change tubes. is it hard? does it cost alot? do i replace old tubes with the same kind? what are good tube brands?
depends on what type of amp you have.
some "valves" (UK), last up to a year, some over 3 years.
even different valves will alter the your sound so it may be a case of try before you buy or you could end up with loads of them.
My gear:
Fender 50th anniv American Strat Deluxe NICE
Fender Eric johnson Strat SEXY
Gibson SG Special Gothic II RAW
Ibanez JS 1000 VERSATILE
Gibson Les Paul Custom OOH BABY
Mesa Boogie Dual Rectifier Head & Cab LET'S ROCK