Bilateral current source 2 (CB20819E)

We found this circuit in an American publication from the 1980s. Equivalent modern operational amplifiers can be used.

LED Binary Counter (CB4345E)
This circuit came out in an American magazine that no longer exists. It's the Electronic...
Code Switch (CB10287E)
This circuit originally came out in a Budget Electronics from 1981. The American magazine no...
LM382 Preamplifier (CB15083E)
This is the traditional audio preamp configuration with the National Semiconductor LM382. The...