D-Max wrote: LordAli, I shure would like to have your drawn schematic. I got some ideas to make a JTM45+100 (notice the plus), where the output stage can be switched between a JTM45/100 4-tube dual OT SS rectified output stage and a 2-tube, single OT JTM45 output stage with a GZ34. Possibly also high/low B+ switching.
D-Max
JTM45-100 RI got that switching (50W/100W) by connecting another speaker cabinet to second OT. But when you want vacuum rectifier, you can have it even in 100W amp.But you need at least 2 GZ34, better 3 rectifiers to run amp properly on EL34 (I don't know KT66 characterictics).
Another 2 or 3 GZ34s need another winding on MT (5V@4 - 6A = 30W on MT). Better is to have each GZ34 with own secondary winding (350-0-350) and in result you've got 2 times greater (even in size) mains transformer. If you run GZ34s from common winding in parallel, there's problem with tubes oscillations......
if you finish that amp, you can post results, I'm really curious