This circuit was obtained from ancient American documentation based on the application of neon lamps. The SCR is according to the controlled load. It really is a power control.
This receiver was found in a documentation by Gernsback from 1960. The circuit uses high impedance...
This low distortion circuit was found in a 1964 Electronic Design. The transistor admits...
We found this audio preamplifier circuit with a 741 operational in a 1976 publication. However,...