This circuit was featured in the March 1972 issue of Radio Electronics magazine. It adds automatic gain control to turntables by acting directly on the cartridge signal.
With the coded activation of the relays, it is possible to control which of the 16 outputs...
The integrated circuit used in this application is not very common. Transistors and resistors...
This simple circuit makes use of neon lamps to indicate the voltage of a power grid. The lamps are...