This NEC commercial amplifier was manufactured in Japan in the 1960s. The circuit uses 4 transistors from the time and was powered by a 9 V battery voltage formed by large batteries.
The accuracy of this 3-digit digital capacitor meter depends on the tolerance of the components used and...
This volume control by direct voltage makes it possible to use a remote potentiometer to control the...
This circuit was found in a 1987 magazine. It consists of an oscillator controlled by the...