This small phonographic amplifier was found in a 1967 General Electric documentation. The integrated circuit is from that time, providing 1.5 W of output power.
This circuit is recommended for alarm systems since it has a good output stage. The circuit is...
) Suggested by Philips in a 1968 documentation this circuit has very high 10 ohm on-load voltage...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...