Found in a 1980s documentation, this amplifier uses an integrated circuit that is not easy to obtain now as it is of the era. The circuit is intended for FI ceramic filter circuits.
We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994....
In the circuit of the figure, we have an application different from 4093. The astable...
We found this circuit in a Poptronics from 1998. The circuit can be extended to more competitors...