Originally Posted by Daniel
i assume so - this is the exact situation these things were designed for - but i know nothing about those line 6 valve amps.
with some valve amps you can also remove a pair and run on half power. Again, with not knowing the amp i couldn't say if this is possible in that amp and how safe it is to do, so you would want to do a little reading up on the subject before you do that.
Also, are you able to bias the amp? or is it fixed? amps need to be biased for the valves you are running. For example if you changed from 6L6s to EL34s or KT88s you would need to make adjustments for this. If you cant make these adjustments you are stuck with 6L6s and their variants.