[Amps] 4CX1500 class AB1 vs. AB2

[Mike McCarthy, W1NR]

I have decided to build a 4CX1500 amp.  I have a couple of tubes and sockets
already. I know that it is designed for class AB2 service for very low
distortion.  This seems to limit the tube to 1100W output.  I am considering
adding a switch to change the screen and grid bias to allow me to run it in
AB1 service as well for 1500W output.

I do know that if the tube looses screen bias when the plate voltage is
applied catastrophic damage to the tube can result, so I will use a lockout
mechanism to prevent switching when HV is on.  In addition, separate bias
pots for each setting.

Is there anything else I need to look out for?  The specs do not show AB1
service, but I assume it can be set up the same as a 4CX1000.  Am I wrong?

Thanks,
Mike, W1NR