Found in a Philips publication from the 1970s, this circuit uses a DO040, which is difficult to obtain today. The circuit is powered by 12 V on pins indicated in the diagram.
This interesting bandpass filter using an operational amplifier 741 has its cutoff frequency...
January 2017 - Mouser Electronics is announcing the availability of the new OptoMOS® CPC1010N...
This circuit was obtained in the Audio Handbook of the National Semiconductor of 1977. The...