This 2-tube amplifier was found in a Japanese publication of 1964. The circuit has excellent sound quality. The power supply is not given and must provide a voltage of 300 V.
This circuit makes use of a PLL 567 and the components must be calculated according to the desired...
The transmitter can be that of CB9574E. This receiver uses a PLL to directly trigger a sensitive relay....
This circuit is from a 1967 US publication. The configuration can serve as a basis for designs...