#1
i have a few questions about tubes

My amp uses KT77 power amp tubes and i need to replace them, if i replace them with JJ KT77's would i need to rebias the amp?

how do i know when a pre amp tube needs replacing?

my amp uses 4 pre amp tubes but has 6 pre amp tube sized tubes connected, what are the other 2 tubes for?

it's a burman pro 501 if that helps

thanks for any help
Quote by bassmanjoe08
Dan

Don't stop being you <3


Quote by fatgoogle
I think after this relentless adding for the last 10 mins, that Dan is the coolest looking. Goddamn welsh people and my great etc etc etc etc etc granddad is welsh.
#2
if the burman is self biasing, you don't need to, look in the manual or their site
lol@u
#3
not really a chance of looking at the manual or their website as the i bought the amp second hand and it's roughly 30 years old and the company is out of business now. i doubt it's self biassing due to the age of it
Quote by bassmanjoe08
Dan

Don't stop being you <3


Quote by fatgoogle
I think after this relentless adding for the last 10 mins, that Dan is the coolest looking. Goddamn welsh people and my great etc etc etc etc etc granddad is welsh.
#4
nothing to do with age, but i don't think it is, my limited electronics knowledge leads me to believe there are too many tubes for it to be self biasing
lol@u