This circuit is from the Texas Instruments operating amplifier manual. Any operational can be used and the font need not be symmetrical. Rf and Rg determine the gain of the circuit.
I found this circuit in an Electronics Handbook from 1989. The circuit can be assembled with a...
The TDA2613 is the mono version of the TDA1521A and has pinouts compatible with an integrated...
This sound effect circuit uses only one integrated. We found it in a 90's EDN. The effects can be...