stereoexpensive to build, but under certain circum-
Believe it or not, stereo comes from a Greekstances is more susceptible to noise pickup.
word that means solid. We use stereo orunity gain
stereophony to describe the illusion of a con-A circuit or system that has its voltage gain
tinuous, spacious soundfield that is seeminglyadjusted to be one, or unity. A signal will leave
spread around the listener by two or more re-a unity gain circuit at the same level at which
lated audio signals. In practice, stereo often isit entered. In Mackie mixers, unity gain is
taken to simply mean two channels.achieved by setting all variable controls to the
sweep EQmarked OU� setting. Mackie mixers are opti-
An equalizer that allows you to Osweep� ormized for best headroom and noise figures at
continuously vary the frequency of one or moreunity gain.
sections.VLZ
symmetrically balancedAcronym for very low impedance.
See balanced.(Impedence is measured in ohms represented
tinnitusby the W symbol, which is the last letter of the
The ringing in the ears that is producedGreek alphabet. This is why the letter Z is used
with prolonged exposure to high volumes. Ainstead of I.) VLZ is one of the most important
sound in the ears, such as buzzing, ringing, orreasons why inherent noise levels on Mackie
whistling, caused by volume knob abuse!mixing boards are so minuscule. Thermal
trimnoise is something thatOs created by all cir-
In audio mixers, the gain adjustment for thecuitry and usually transistors and resistors are
first amplification stage of the mixer. The trimthe worst culprits. The basic rule with thermal
control helps the mixer cope with the widelynoise is: the higher the impedance, the more
varying range of input signals that come fromthe noise. MackieOs VLZ design reduces ther-
real-world sources. It is important to set themal noise by making internal impedances as
trim control correctly; its setting determineslow as possible in as many places as possible
the overall noise performance in that channelwithin the console. VLZ is achieved by scaling
of the mixer. See mic preamp.down resistor values by a factor of three or
TRSfour � resulting in a corresponding reduction
Acronym for Tip-Ring-Sleeve, a scheme forin thermal noise. This is especially true for the
connecting three conductors through a singleconsoleOs mixing buses.
plug or jack. 1�4" phone plugs and jacks and 1�8"volume
mini phone plugs and jacks are commonlyElectrical or sound level in an audio system.
wired TRS. Since the plug or jack can carryPerhaps the only thing that some bands have
two signals and a common ground, TRS con-too much of.
nectors are often referred to as stereo orVRMS
balanced plugs or jacks. Another common TRSSee RMS.
application is for insert jacks, used for insert-wet
ing an external processor into the signal path.With added reverberation or other effect
In Mackie mixers, the tip is send, ring is re-like echo, delay or chorusing.
turn, and sleeve is ground.XLR connector
TSSee Cannon.
Acronym for Tip-Sleeve, a scheme for con-
necting two conductors through a single plug
or jack. 1�4" phone plugs and jacks and 1�8" mini
phone plugs and jacks are commonly wired TS.
Sometimes called mono or unbalanced plugs
or jacks. A 1�4" TS phone plug or jack is also
called a standard phone plug or jack.
unbalanced
An electrical circuit in which the two legs of
the circuit are not balanced with respect to
ground. Usually, one leg will be held at ground
potential. Unbalanced circuit connections re-
quire only two conductors (signal Ohot� and
ground). Unbalanced audio circuitry is less
41 |
ACEC
