Manual

The Technical Stuff
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Knee
A compressor's knee determines whether the device will reach maximum gain reduction quickly or
slowly. A gradual transition (“soft knee”) from no response to full gain reduction will provide a
gentler, smoother sound, while a more rapid transition (“hard knee”) will give an abrupt “slam” to
the signal. The 1176LN utilizes soft knee compression and limiting, which is generally preferred for
most musical applications; hard knee compression or limiting is more often used in applications
where instrumentation (such as broadcast transmitter towers) must be protected from transient signal
overloads.
Attack and Release
The main key to the sonic imprint of any limiter or compressor lies in its attack and release times;
these are the parameters which most affect how “tight” or how “open” the sound will be after gain
reduction. The attack time describes the amount of time it takes the limiter/compressor circuitry to
react to and reduce the gain of the incoming signal, usually given in thousandths of a second
(milliseconds) or even millionths of a second (microseconds). A fast attack kicks in almost
immediately and catches transient signals of very brief duration (such as the beater hit of a kick drum
or the pluck of a string), reducing their level and thus “softening” the sound. A slow attack time
allows transients to pass through unscathed before compression begins on the rest of the signal.
The release time is the time it takes for the signal to then 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. In the 1176LN, both the attack and release times are user-selectable. Attack time can be
set to between 20 microseconds and 800 microseconds (and in the case of the 1176AE, a 10ms
“SLO” attack mode), these are among the fastest attack times offered by any analog compressor.
Release time can be set to between 50 milliseconds and 1100 milliseconds (1.1 seconds). Unlike
many other devices, however, the 1176LN attack and release times get faster, not slower, as their
corresponding knobs are turned up (clockwise).
Program-Dependent Release
Program-dependent release is a feature of many compressors. The motivation for having program-
dependent release is as follows: After a transient, it is desirable to have a fast release to avoid
prolonged dropouts. However, while in a continued state of heavy compression, it is better to have a
longer release time to reduce the pumping and harmonic distortion caused by repetitive attack-
release cycles. It is a fact that the 1176 compressor employs a release mechanism that is heavily
program-dependent. There are three features to a program dependent release: A fast release-time, a
slow release-time, and a transition-time. The fast release time is the effective release time after
transients; the slow release time is the release time after sustained high-RMS signals. The transition
time expresses how long the signal must be “in compression” before the slow release time comes
into effect. The original “Bluestripe” and 1176AE has a different slow release-time and transition-
time when compared to the “Blackface” edition.