This transistor amplifier was published in Radio Electronics magazine in July 1965. It used newly released silicon transistors with excellent sound quality.
This circuit for controlling high power in the AC network was found in a Motorola documentation from 1968....
This amplifier is specifically designed for portable radio and recorders with a 4 ohms load....
This circuit was found in a 1973 Radio Elettronica magazine. The Italian magazine no longer...