This transistor class B 5 W amplifier was found in a 1969 Mullard documentation. The transistors are from that time, and modern equivalents may eventually be used.
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...