This VCA was found in the July 1988 issue of Radio Electronics magazine. It uses an OTA op amp and has its gain adjusted by the voltage at the gain input.
We found this circuit in a European schematic manual from the 1980s. The circuit is still current, and...
This circuit is basically the same configuration as the previous one with a power stage with...
This positive voltage regulator with 70 V output was found in a National Semiconductor manual from...