Chapter 3: Glossary of Terms
31
English
Amplifi er Application Guide
the amplifi er that allows a single input to feed two combined
output channels in order to provide a single output with twice
the current of an individual channel in Stereo or Dual mode.
Peak
On a graph of a sound wave or signal, the highest point in the
waveform. The point of greatest voltage or sound pressure in
a cycle.
Phase Response
The measure of displacement of a time-varying waveform
between an amplifi er’s input and output. Expressed in
degrees.
Phone Plug
A cylindrical plug, usually 1/4-inch (6.35-mm) in diameter. An
unbalanced phone plug typically has a tip for the hot signal
and a sleeve for the shield or ground. A balanced phone
plug typically has a tip for the hot signal, a ring for the return
signal, and a sleeve for the shield or ground.
Phono Plug
A coaxial plug with a central pin for the hot signal and a ring
of pressure-fi t tabs for the shield or ground. Phono plugs are
used for unbalanced signals only. Also called an RCA plug or
pin jack.
PIP™
PIP stands for Programmable Input Processor. These are
optional modules that can be plugged into any PIP-compat-
ible amplifi er. There are a variety of PIP modules with varying
functions. Since fi rst introducing PIP-compatible amplifi ers
and PIP modules, Crown has updated the PIP standard. This
affects which PIP-compatible amplifi ers can host certain PIP
modules. Following are descriptions of the two PIP standards.
Crown’s original PIP module was designed with a 22-pin edge
connector, which mated with a slide-in card rail on PIP-com-
patible amplifi ers.
PIP2™
The PIP2 standard, announced in 1998, upgraded the PIP
feature set and requires both 18- and 20-pin ribbon cables
which mate with a PIP2-compatible amplifi er using standard
ribbon connectors.
Polarity
In electronics, the relationship between two points that have
opposite electric potentials (one is positive, the other nega-
tive) irrespective of time. This is not the same as being 180
degrees out of phase (although the results can be similar).
Phase implies a relationship with time, polarity does not.
Potentiometer (Pot)
An electronic component that is used to provide variable
control over an electronic circuit. It is usually controlled by a
rotary knob which can be turned by hand; a volume control is
a good example of this.
Power
Literally, the rate at which energy is consumed. Power is
expressed in Watts, abbreviated W. In electrical circuits,
power is determined by the amount of resistance (R) times
the amount of current squared with the following expression:
P=I
2
R.
Power Amplifi er
In audio, an electronic device that amplifi es or increases the
power level fed into it to a level suffi cient to drive a loud-
speaker.
Radio Frequency Interference (RFI)
Radio-frequency electromagnetic waves induced in audio
cables or equipment, causing various noises in the audio
signal.
Removable Terminal Block (Buchanan
®
, Phoenix)
A series of screw terminal connections arranged in a line on a
removable connector. Often found in three-terminal and four-
terminal versions in audio applications. Often referred to by
their brand name, such as “Buchanan
®
” and “Phoenix.”
Resistance
The opposition of a circuit to a fl ow of direct current. Resis-
tance is measured in ohms. The symbol
Ω
(omega) is often
used to represent resistance. Ohms law defi nes resistance as
voltage (V) divided by current (I) with the following expression:
R=V/I.
Resistor
An electronic component that opposes current fl ow.
Sensitivity
In audio terms, sensitivity is the minimum amount of input
signal required to drive a device to its rated output level.
Normally, this specifi cation is associated with amplifi ers and
microphones, but FM tuners, phono cartridges, and most
other types of gear have a sensitivity rating as well.
Shield
In electronic terms, a shield is a conductive enclosure,
protecting its contents from magnetic and electrostatic fi elds.
Since audio conductors and circuits tend to be extremely
sensitive to such fi elds, shields are very important. In cabling,
shields often consist of braided copper strands wrapped
around the signal conductors. The amount of coverage the
shield provides is directly related to the noise and hum per-
formance of the cable. Some cables offer a shield consisting
of a thin wrap of metallic sheeting, which can offer complete
coverage of the encased signal conductors.
Signal-To-Noise Ratio (S/N)
The ratio in decibels between signal voltage and noise volt-
age. An audio component with a high S/N has little back-
ground noise accompanying the signal; a component with a
low S/N is noisy.
Sine Wave
A wave following the equation y = sin x, where x is degrees
and y is voltage or sound pressure level. The waveform of
a single frequency. The waveform of a pure tone without
harmonics.
Single-Ended
An unbalanced line (see Unbalanced).
Slew Rate
Slew rate is the ability of a piece of audio equipment to
reproduce fast changes in amplitude. Measured in volts per
microsecond, this spec is most commonly associated with
amplifi ers, but in fact applies to most types of gear. Since high
frequencies change in amplitude the fastest, this is where
slew rate is most critical. An amp with a higher slew rate will
sound “tighter” and more dynamic to our ears. Slew rates in
amplifi ers are often limited to useful levels to provide protec-
tion to the amplifi er from Radio-Frequency Interference (RFI).
