The operational amplifier used is not common today, but the circuit can be implemented with modern operational ones. The gain is 1000 and the source must be symmetrical.
The correct connection of speakers and tweeters in a speaker to obtain better sound quality,...
This circuit with germanium transistors was found in a Mullard manual from 1960. The components depend...
This circuit was found in a Popular Electronics from the 90s. The components admit equivalents and the...