I have a 5150 II.

My buddy just gave me 2 Mesa Boogie Power Tubes that he had lying around.

Should I put these in? Or should I buy another 2 and put 4 in?
If I buy two new ones, do they have to be the same?

How do I change them?

Any help is appreciated, thank you.
I just had this problem, buy 2 more and they have to match each other look at the bottom of the tube. get the info off that or take the tube to GC so they can match the 2. If you dont have that kind in your amp you going to have to rebias your new quad of tubes. My tech told me if I stay with the mesa brand I wont have rebias next time. carefully pull them out.
tone slut

Mesa Boogie Mini Rectifier
jet City 2112 Combo
Gibson SG Standard
Gibson Les Paul Studio
Fender Classic Vibe Telecaster
Last edited by ksmc at Jun 25, 2009,
are the 2 that you have matched? If you do decide to buy 2 more, be sure to get a matched pair. And have your amp biased afterwards.