[mike s]

Here's another phase splitter that could be used with battery valves -

http://mike.wepoco.com/Home/retro-ge...plifiers/ech21

This circuit appears from time to time in Mullard datasheets for frequency changers. Not sure if it ever appears in datasheets for battery valves. In the old days when QPP (class B) was used in some battery sets a phase-splitter auto-transformer was generally used.