Can't not be push pull with one ecl 85 triode input &pentode driver. Is quad parallel 300b
the 50 watts are a little too optimistic for me, even with 300b xls tubes. I like allnic aka Silvaweld preamps and amps they have a nice sound.
you can build a phase splitter with one double triode, this was done in the past with tube oscilloscopes called "long tailed pair or schmitt"
P.S
if you ever see this silvaweld mono amp buy it immediately wonderful 20 watt 300b
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