This circuit doubles the frequency of an audio signal, thus changing its timbre. The circuit was found in an Elektor from the 90s. The components are common today.
This circuit was obtained from a 1967 General Electric manual. The circuit uses components of the time,...
This circuit uses an amplifier from National Semiconductor, uncommon nowadays. The numbers in...
This circuit is powered by the source of the equipment under analyze. We found this configuration in a 1974...