Hmmm I can just remember a little mono test amp that was in Practical Wireless in the middle 1960s. It used a single ECC82 in class A push-pull and was its own phase splitter. I guess you could have 2 of them for stereo - always assuming you could get transformers!
Hey, if you don't mind
one coupling capacitor (each channel) you could stick an ECC83 on the front for the three valve high gain version
... might even have enough gain to be able to add passive tone controls