Converting PP stages to triode op

[david.rogers]

This has probably been covered before, but I have a slight confusion. I want to convert my CJ PP amp to triode operation - at least to try it. The attached schematic (can't remember if it came from the WAD forum or not) shows how to disconnect the screen grid from the OT tap and connect in via a 100 ohm resistor to the anode/OT primary. So far so straightforward. However, in my amp (see attached schematic) there is already a 100 ohm 5 watt resistor connected between the screen grid and the OT tap. My question is do I simply need to disconnect the resistor from the OT tap and reconnect it to the primary, or is it more complicated than that?

Thanks
David

[NickG]

No, thats it, leave the UL tap disconnected, and the SG connected via the resistor to the anode.

[david.rogers]

Is there any reason why I shouldn't wire a switch into the circuit so I can go back and forth between ultralinear pentode and triode?

[NickG]

None, as long as the switch can cope with the voltage. Work on double the H+ for a max voltage and you won't be far wrong.