Found in an Elektor from the 90s, this circuit is suitable for viewing audio signals on an oscilloscope. The operational amplifier admits equivalent.
The circuit shown in the figure was found in a 1974 publication. The field effect transistor may...
I found this circuit in an English publication from 1989. This configuration can be mounted with...
We found this circuit in a small espionage manual from 1993. The components are current, and the...