I have an older sweep tube amp in 1x3 configuration using 6je6's. Given the availability and cost of NOS tubes for this, what is the feasibility of re-tubing this with something more readily available like EL509/519's, or maybe 572B's? (Although I suspect I don't have the voltage required by some of the big glass.) Doesn't have to remain in the same config. I'm not looking for a huge wattage increase (no, I don't play on the Supabowl, 10-4, Rogeee..... :roll: ), just something in the 180-250W range would be adequate, any more than that would just be icing on the cake. Any thoughts on the subject? Suggestions? I have a feeling that the cost to re-invent the wheel is going to be not worth the effort, but I hate to give up on an amp that's almost mint except for the tubes. Am I beating a dead horse here? TIA