This 12.5 W quasi-complementary amplifier was found in a 1969 General Electric publication. Note the high supply voltage. Transistors are common types at the time.
This amplifier was found in a Japanese publication in 1972. Transistors are uncommon today, and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...