This 1000: 1 voltage-controlled filter circuit was found in an Electronics Today International in a 1980s edition. The circuit is based on components of the time.
We found this audio preamplifier circuit with a 741 operational in a 1976 publication. However,...
The arranjment sohon Bellow, and simulated in the Multisim Blue allows to see in the oscloscope...
This 2005 circuit was found in an English publication and can be implemented with virtually any...