Universal Audio 4-710d Manual page 31

Glossary of Terms
External Clock - A clock signal derived from an external source. (See "Clock")
FET - Short for "Field Effect Transistor" which is a type of transistor that relies on an electric field to
control the shape, and hence the conductivity, of a "channel" in a semiconductor material.
Front End - Refers to a device that provides analog and digital input/output (I/O) to a digital audio
workstation (DAW). (See "DAW")
Hi-Z - Short for "High Impedance." The 4-710d's Hi-Z input allows direct connection of an instrument
such as electric guitar or bass via a standard unbalanced 1/4" jack.
High Resolution - In digital audio, refers to 24-bit signals at sampling rates of 88.2kHz or higher.
Hz - Short for "Hertz," a unit of measurement describing a single analog audio cycle (or digital
sample) per second.
Impedance - A description of a circuit's resistance to a signal, as measured in ohms or thousands of
ohms (K ohms). The symbol for ohm is Ω.
Internal Clock - A clock signal derived from onboard circuitry. (See "Clock")
I/O - Short for "input/output."
kHz - Short for "kiloHertz" (a thousand Hertz), a unit of measurement describing a thousand analog
audio cycles (or digital samples) per second. (See "Hz")
JFET - Abbreviation for Junction Field Effect Transistor, a specific type of FET which has some
similarities to traditional bipolar transistor designs that can make it more appropriate for use in some
audio circuit designs. (See "FET")
Jitter - Refers to short-term variations in the edges of a clock signal, caused by a bad source clock,
inferior cabling or improper cable termination, and/or signal-induced noise. A jittery signal will contain
spurious tones at random, inharmonic frequencies. Usually, the jitter will be worse with higher signal
frequencies. The internal digital clock of the 4-710d was designed for extreme stability and jitter-free
operation, and its onboard phase aligned clock conditioner circuitry removes jitter from external
sources, so conversion quality is unaffected by clock source.
Light Pipe – A digital connection made with optical cable. This was a phrase coined by Alesis to make
a distinction between the proprietary 8-channel optical network used in their ADAT products and
standard stereo optical connectors used on CD players and other consumer products.
Line Level - Refers to the voltages used by audio devices such as mixers, signal processors, tape
recorders, and DAWs. Professional audio systems typically utilize line level signals of +4 dBm (which
translates to 1.23 volts), while consumer and semiprofessional audio equipment typically utilize line
level signals of -10 dBV (which translates to 0.316 volts).
Low Cut Filter - An equalizer circuit that cuts signal below a particular frequency.
Mic Level - Refers to the very low level signal output from microphones, typically around 2 millivolts
(2 thousandths of a volt).
Mic Preamp - The output level of microphones is very low and therefore requires specially designed
mic preamplifiers to raise (amplify) their level to that needed by a mixing console, tape recorder, or
digital audio workstation (DAW).
Native - Refers to computer-based digital audio recording software controlled by the computer's
onboard processor, as opposed to software that requires external hardware to run.
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