Before I presented the superheterodyne type but this time I've fixed for more usable shape. I've wanted "direct speaker drive" (withOUT transistor active speaker) to enjoy "pure vacuum tube sound" but three battery driven tubes were not enough to do it (or my design is not so good.)

So this time I simply added audio amplifier at the end of circuit.

This the the whole circuit. Indeed, super simple compared to my 48kHz USB DAC, but works very cleverly. The first tube (left end) is 1R5 heptode working as local oscillator and frequency mixing. The oscillator coil is the one for transistor circuit (Red coil). After passing 1R5, 455kHz signal goes to 6418 subminiature tube amplifier, and goes to reflex circuit, which demodulate 455 kHz AM signal to audio, and finally the last tube is simply audio amplifier and goes to speaker through impedance trans. Actual operation is as follows. Indeed, it does not still exhibits so high-sensitivity but anyway speaker driving pure vacuum tube superheterodyne radio is done!