The integrated circuit used in this amplifier is uncommon today, since the project is from the 90s. The power is 24 V, and the gain of the circuit is 40dB. The input resistance is 1 M ohms.
This amplifier was published in the July 1961 Radio Electronics magazine. It announced the release of...
This circuit was found in a 1967 Electronics World. SCRs are according the controller load,...
This sophisticated circuit using a liquid crystal display was found in Radio Electronics from the...