A416 A426 A346 are a stereo Amplifier 70-s product by SCOTT. It using symmetrical supply 27Volts.
Appearance inside of the amplifier: HERE.
Below is cropped and edited schematic from the original one:
Servo bias transistor using 2SC9630, but its may be same with BC547 nowadays.
Driver transistor using 2SC1166 or 2SC1860, its below 1Watt dissipation ( DATASHEETS ).
Final output transistor using 2SC789 and its able to make power dissipation until 30 Watts ( DATASHEETS ).