The integrated circuit used in this' 90s amplifier is not very common today. The supply is 24 V, the gain is 50dB and the input resistance is 100 k. The circuit is from an old circuit manual.
With 3 transistors, we found this receiver in a documentation from 1966. The circuit has an output...
This sonic relay or vox was found in a Popular Electronics from the 90's. The power MOSFET can be of...
This tri-state comparator was found in a circuit manual from the 1980s, but it can be easily...