Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern equivalents can be used. The high voltage supply suggests its use with tube amplifiers.
The L293 circuit is not common today. We found this circuit in the 1982 SGS linear integrated...
We found this bridge circuit in Electronics Now magazine from September 1995. The instrument can...
We found this divider in a circuit manual from the 90s. The circuit is intended for operation with...