We found this circuit in an old publication (1977) using common transistors at the time and now they can hardly be found. We exchange these transistors by the pair BC548 / 558 to the drivers and the pair BD135 / 136 to the output transistors thus making possible the assembly today. The circuit provides excellent sound quality to a headset with good power. In the original it is powered by battery 9 V, but as has high consumption. The source must have excellent filtering with at least 300 mA.Two amplifiers to be used in a stereo headset, one for each channel.
