This powerful high-fidelity amplifier was described in an article in Radio Electronics magazine in December 1973. Note the use of 8 high-power transistors that must be mounted on excellent heat sinks.
This circuit is from Radio Electronics from March 1977. The integrated circuit is from that time...
This 1.2 to 32 V x 3 A regulator was found in an 80's EDN. The power components must be equipped...
This power control from Motorola's 1971 SCR Power Control Fudamentals can control full wave loads...