ABSTRACT
Integrated circuits (ICs) are just circuits pre-wired on a silicon chip. The operational amplifier (op-amp) is the most important and most commonly encountered standard circuit building block in audio electronics, and as such a significant portion of this chapter is dedicated to understanding and using opamps effectively. Opamps come in a number of standard IC packages, containing one, two, or four opamp circuits on a single chip. The 4000 series consists of a large collection of utility ICs, mainly intended for building digital logic control oriented circuitry. Optocouplers come in a number of different forms, but usually involve a Light Emitting Diode shining on a light sensitive device of some kind. A signal entering on one side of the device causes the light emitting diode within to shine brighter and dimmer, in time with the variations in the signal.
