UL mode

[isaac_teller]

Hello. Is there a more sophisticated way to switch an amp from pentode mode to UL mode other than a regular toggle switch? Thank you.

[shooter]

more sophisticated way

absolutely, I can probably get a 10 part count circuit but we usually strive for KISS 

use the switch for experimenting, you'll probably find what most have, it's either hardwired UL or Pentode, no real advantage in otherwords

[pdf64]

Bear in mind there are massive back emf voltage spikes on the plates of overdriven power tubes; so depending on the HT voltage, maybe 2 to 4kV between the terminals of the poles of a dpdt ul-pentode switch. I don’t think it’s good practice to introduce switches / anything there, just use direct tidy wiring, use a switch in the design phase only preferably.

[sluckey]

Hello. Is there a more sophisticated way to switch an amp from pentode mode to UL mode other than a regular toggle switch? Thank you.

Sure. Use an extra set of sockets. Wire one set for pentode and wire the other set for U/L. Swap tubes back and forth.

Or, you could wire two sets as above but put two sets of tubes in. Use a SPDT switch to connect the cathodes of only one set to ground.

I've never tried either of these Rube ideas, so proceed with caution.   

[isaac_teller]

Thank you everyone!