This circuit is temperature stabilized. Modern equivalent transistors can be used, and the power supply can actually be between 9 and 12 V. The circuit is from an old documentation.
The LM381 integrated circuit is not very common today. The circuit is from an old publication, but it can be...
This circuit is based on the TDA3810N. We found it in the March 1992 issue of Radio Electronics magazine....
This is another quick adder that we found in an Electronic Design from the 80s. It also applies to...