The circuit is from the 1977 National Semiconductor Audio Handbook. The bass and treble control is Baxandall type. The integrated circuit used is not common today.
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...