Amp

Ampere. The international base unit of electrical current that represents the rate flow of electric charges through a conductor. Symbolized by “A.” 1 amp is equal to the steady current produced by 1 volt applied across a resistance of 1 ohm.

Amplifier

An electronic device used to increase the voltage amplitude of a signal.

Amplifier classifications

Audio amplifiers are typically described by “class”. There are four primary classes used in A/V system designs: A, B, A/B, and D.

Analog

A continuously varying action or movement that takes time to change from one position to another. Standard audio and video signals are analog. An analog signal has an infinite number of levels between its highest and lowest value (unlike digital, in which changes are in steps).

Analog control

A method using continuously varying voltage levels to provide control of equipment.

AWG

American Wire Gauge. A standard measurement for wire conductor diameter.

Balanced audio

The audio signal that is carried on three wires (or five wires for stereo pair), with two of them carrying the same signal but with reversed polarity, and a third wire for shielding. Since the two signal wires would pick up virtually identical noise from outside (common mode noise), and that noise can be canceled out at the receiving end by a differential amplifier, the balanced audio is much less susceptible to hum and interference from long cable runs.

Capacitor

A device made up of one or more pairs of conductors, separated by insulators and capable of storing an electrical charge. When there is a difference of potential between the conductors, and because current cannot flow through the insulator, an electrical charge is stored.

CEDIA

Custom Electronic Design and Installation Association. CEDIA is an international trade association of companies specializing in planning and installing electronic systems for the home. This association offers an annual expo.

D/A

Digital to analog.