Operating instructions

Glossary Of Terms
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Millisecond (ms) - A thousandth of a second.
Patch bay - A passive, central routing station for audio signals. In most recording studios, the
line-level inputs and outputs of all devices are connected to a patch bay, making it an easy matter
to re-route signal with the use of patch cords.
Patch cord - A short audio cable with connectors on each end, typically used to interconnect
components wired to a patch bay.
Panel aging - More related to the amount of actual use rather than age in years, this is a phenomenon
which affects the the threshold (and, to a lesser degree, attack time and release time) of an electro-
optical compressor. The more "aged" the EL panel, the greater the amount of gain reduction will need
to be applied. Panel aging is probably a major reason why the same model of electro-optical
compressor can sound subtly different between units.
Peak reduction - A synonym for compression or limiting.
Photo-electric cell (“photo-cell”) - A light sensitive device whose electrical resistance changes
depending upon the intensity of light to which it is subjected.
Program dependent - Refers to a parameter that varies according to the characteristics of the
incoming signal. The 2-LA-2 compressor and limiter ratio, as well as the attack time and release time,
are all program dependent.
Release time - The time it takes for a signal to return to its initial (pre-compressed) level. If the
release time is too short, "pumping" and "breathing" artifacts can occur, due to the rapid rise of
background noise as the gain is restored. If the release time is too long, however, a loud section of the
program may cause gain reduction that persists through a soft section, making the soft section
inaudible. The 2-LA-2 features a dual-stage release, where it takes approximately 60 milliseconds for
the first 50% of release, then from 1 to 15 seconds for the final release.
Terminal Strip - An insulated stamped strip of tin-plated loops of copper, used for multiple electrical
or audio interconnections. Sometimes called a “barrier strip.”
Threshold - A term used to describe the level at which a compressor starts to work. Below the
threshold point, the volume of a signal is unchanged; above it, the volume is reduced.
Transient - A relatively high volume pitchless sound impulse of extremely brief duration, such as a
pop. Consonants in singing and speech, and the attacks of musical instruments (particularly
percussive instruments), are examples of transients.
TRS - Short for “Tip/Ring/Sleeve,” a standard quarter-inch jack connector, with the tip and ring
carrying audio signal and the sleeve attached to the shield of the cabling, thus providing ground.
When used for mixer channel or bus inserts, the tip and ring will typically carry send and return
signals, respectively. When used for balanced connections, the tip and ring will carry the same audio
signal, with one signal out of phase with the other.
XLR - A standard three-pin connector used by many audio devices, with pin 1 typically connected to
the shield of the cabling, thus providing ground. Pins 2 and 3 are used to carry audio signal, normally
in a balanced (out of phase) configuration.