The two above variations should maintain a correct bias for the center triode. One potential problem with all these variations is the danger of exceeding the maximum heater-to-cathode voltage for the triode. At least two separate heater windings will be needed to keep things safe: one referenced to 250 volts and the to 50 volts, for the examples given.
   Comparing the current flow for this circuit versus the textbook SRPP reveals the single-ended nature of this circuit versus the push-pull nature of the SRPP.

    The circuit above shows one way to build a Triple Triode Mu Follower. The two coupling capacitors define a voltage divider that will work to bias up the center triode well in the absence of grid current. If the center triode's grid draws too much current, it will end up charging the coupling capacitors dissimilarly and upset the voltage ratio. A better plan would be to add an extra resistor to bias the center triode.