We found this circuit in an American documentation from 1975. The list of transistors that can be used is attached to the diagram. Modern types can be experienced.
Found in Exar documentation from the 1980s, this circuit has a 60 dB cutoff at 1800 Hz. The...
We found this circuit in the 1982 SGS Linear Integrated Circuits manual. The L78xx is equivalent to 78xx...
This circuit was found in an American technical manual from the 1980s. The LM111 is an uncommon...