This circuit was found in 1980s American documentation. The transducer is a piezoelectric capsule and the power supply voltage can be between 3 and 18 V.
This circuit came out in an American magazine that no longer exists. It's the Electronic...
This circuit originally came out in a Budget Electronics from 1981. The American magazine no...
This is the traditional audio preamp configuration with the National Semiconductor LM382. The...