The tail resistor doesn't have anything to do with gain. Figure 1 in post #49 doesn't even have a tail resistor, but it has the same gain as in Figure 3 in post #50. The tail resistor is just there to get a voltage drop without using very much current. Figure 1 needs to be understood because this is the basis for all the LTP splitters. The LTP does not act like a cathode follower, nor a cathodyne, nor a common-cathode gain stage. It works by balancing the current fluctuations between the two triodes. No matter whatever else happens with a LTP splitter, the balancing effect is always there and it will be the dominant effect.