EL84's and 6L6's interchangeable?

[funktree]

I have a Carvin Bel Air/ Its a 2-12 50 watt tube combo with 4 EL84's and 5 12AX7's. I read somewhere on this board about someone switching their tubes to 6L6's in a similar amp. Can I do this without hurting anything and what would be the results soundwise? As you can tell this is my first tube amp

 

[Major Tom]

First, the 6L6's won't physically fit into the smaller EL84's sockets, if they did and even if they were pin for pin compatible and you put 4 of 'em in there you'd burn up the amp since the 6L6's draw a lot more current. You probably heard that EL 34's can be put into a 6L6 amp (or vice versa) with minor mods, those 2 are much more similiar. There aren't any other power tube types that I'm aware of that will work in that amp without MAJOR modifications. The EL 84's are a great tube for guitar, be happy. One thing you can do is remove a pair of them (the 2 inside or the 2 outside), and reduce the output wattage in half, so you can get power tube distortion at lower volumes. Some will say that you will need to change the speaker load (impedence), others say it won't matter....I have done it with Fender amps without a problem. You can also try different brands of the EL 84's and 12AX7's to experiment with trying to get a different sound.