Indeed, no hf oscillator, instead it looks like it uses DC bias via R12. It's also neat to see all the circuitry re-used identically for amplifying the tape in playback, or amplifying the microphone input to record to tape. Was that a standard and obvious plan for the engineers of the time?

I'm also curious if R22, the thermistor, would have been just for thermal protection, or if it was actually used to set the operating point for the output transistors in normal operation? Would it have switched on loud and angry before the transistors warmed up and the bias point cooled down, the opposite of a tube amp?