This circuit consists of a stereo audio compressor. We found it in Radio Electronics magazine from October 1968. The circuit uses an opto-coupler made with a neon lamp and LDR.
This inverse transistor breakdown circuit was found in a 1967 documentation. It applies to modern...
This old amplifier, with germanium transistors, was found in a Japanese technical magazine in...
With this type of circuit, it is possible to obtain high input impedances and, at the same time,...