As I remeber Jadis used KT-88's in the origional amps and they pushed the hell out of the tube, thats why the Chinese KT-88 did not hold up since it was really rated for 35 watts plate dispation and the screen was 4 watts.
The best choice of tube would be the JJ-KT-88 or the winged C KT-88 true Svetlana not the new sensor KT-88 that says Svetlana.
EL-43 is a great tube but at best its a 25 watt tube and the screen disapation is really not rated for the power pushed in Jadis since its ultra linear tap, although a 1k- 2 watt reaistor could be inserted on pin 4 for the screen tap.
this will take the heat off the screen of the EL-34's, KT-90 was molded around sweep tube design, but has a screen voltage increase so it could be run ultra linear screen tap configuration rather than most sweep tubes running 250 volts max screen.
KT-77 is a good tube but where can you find them now I sold my stock of 10 NOS KT-77's years ago and I find the 6CA7 to be equal to the KT-77 and Groove tubes has a nice American 6CA7-GE worth looking at.
The best choice of tube would be the JJ-KT-88 or the winged C KT-88 true Svetlana not the new sensor KT-88 that says Svetlana.
EL-43 is a great tube but at best its a 25 watt tube and the screen disapation is really not rated for the power pushed in Jadis since its ultra linear tap, although a 1k- 2 watt reaistor could be inserted on pin 4 for the screen tap.
this will take the heat off the screen of the EL-34's, KT-90 was molded around sweep tube design, but has a screen voltage increase so it could be run ultra linear screen tap configuration rather than most sweep tubes running 250 volts max screen.
KT-77 is a good tube but where can you find them now I sold my stock of 10 NOS KT-77's years ago and I find the 6CA7 to be equal to the KT-77 and Groove tubes has a nice American 6CA7-GE worth looking at.