Okey. I was suggesting a self split amp. If you ground the input on the out of phase tube you got a cathode feed selfsplit amp with a sweet tone. I write it on the Masco thread.
I vcan not explain it easyer than this. - The easy way is just do a switch that ground the second powertubes input. Your amp have a paraphase phase invertor and it is no risk to do that. Your tech know what i mean. If you/he need more information you can contact me over a PM in Lonewolfs forum.
The other thread is the Masco 50 thread in this forum..