The transistor is a 2SD1593 or equivalent, with a very high gain factor (beta) and average current. Features: Input L + R with low pass filter, bootstrap and Boucherot filter. The 22 ohm resistor and the bulb in the diagram are replaced with a 22 ohm speaker, from a Grundig antique TV, for example. (oversized). The bulb illustrates the useful audio signal output and the 22 ohm resistor illustrates the DC polarization of the transistor through the oversized speaker coil. Circuit made practically!
