This circuit uses an unusual operational amplifier nowadays and has a very low consumption. The number in parentheses corresponds to the second channel, for a stereo version.
This old amplifier, with germanium transistors, was found in a Japanese technical magazine in...
This is the well-known lightning lamp that was published in the March 1988 issue of Saber...
This VFO was found in a 1980s documentation. The central frequency is given by the crystal and the...