Fender amp question

[B36arin]

I figured I'd ask this here, seeing as there are a few amp builders here, and I don't trust google with my old amp...

I have an old Twin Reverb at my parents' house where I'm staying over Christmas. We moved here recently, and somehow one of the power tubes has broken. I haven't turned the amp on since. My question is, is it perfectly safe to unplug another tube and have the amp run on two power tubes instead of four? If so, which ones should I unplug? Is this something that you can do on any amp?

 

[lolzgreg]

IIRC, if you only leave the inner pair of power tubes in, and cut the resistance (ohm rating) in half, you'll be fine.

 

[TheWinterSnow]

IIRC, if you only leave the inner pair of power tubes in, and cut the resistance (ohm rating) in half, you'll be fine.

other way around, you have to double the load. If you have an amp that has an impedance selector switch, you would select half the actual value of the load.