This 10 kHz filter was obtained from an article in Electronics Now magazine in February 1995. The power supply is dual and other equivalent operating conditions can be used.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...