Join Date: Dec 2000
Location: Chicagoland, IL.
On the 5150 I have used Groove tubes, sovteks, RUBY and Svetlanas. I worked at a shop that specialized in amp mods and repair. Groove tubes out of the box, once put into a 5150, burned up half the amp, quite literally, the plate and filiments had somehow shorted together and burned up the circuit board. Like Jay said, it really hinges on how loud, and how often you play, the candle that burns twice as bright, burns half as long.
AS for brands, try whatever you think will do what you want.
One suggestion I have is: in the preamp section get at least one 12AX7WXT or WXB in the 1st tube position on the preamp. The WXB or T is a low noise preamp tube which has reduced microphonics and low noise. The 1st tube is what starts the chain of preamplification, the less noise you start with, the less you'll hear on the output side.
I swear by Sovteks personally, but thats just me.