Found in American documentation from the 90's, this circuit applies to other operational amplifiers. The frequency can be changed by changing the components.
We found this 4-channel mixer in the August 1999 issue of Electronics Now magazine. The circuit can...
The configuration shown makes use of a simple source and the gain is given by the relationship between R3...
This circuit was found in a 1995 documentation and is very simple to assemble, as the components are...