Based on your last post, and before you got things corrected, the EL34's were connected as follows:
Heater: Like it should be.
Cathode & suppressor grid: Like they should be.
Control grid: Connected to about + 450 V.
Screen grid: Connected to - 57 V.
Anode: Connected to nothing.
I'm really puzzled that you blew a 1 A fuse in this situation, since it would need about 500 mA of control grid current per EL34 to do so.
Heater: Like it should be.
Cathode & suppressor grid: Like they should be.
Control grid: Connected to about + 450 V.
Screen grid: Connected to - 57 V.
Anode: Connected to nothing.
I'm really puzzled that you blew a 1 A fuse in this situation, since it would need about 500 mA of control grid current per EL34 to do so.
I confirm that the el34s were connected as you wrote.
do you have any indication to give me on the measurements to be made with the oscilloscope and the function generator?