4
C
CE
EL
L--2
2A
A
™
™
Dual Compressor/Expander/Limiter
Thank you for purchasing the CEL-2A. You’ll find plenty of features and versatility in this single-rack space‚ dual
compressor. The CEL-2A can be operated as either two independent compressors or as a linked‚ stereo compressor with
true RMS summing. High-quality‚ voltage-controlled amplifier (VCA) and RMS-rectifier integrated circuits are used to
maintain low distortion and excellent noise performance.
This unit has fully-balanced inputs and outputs‚ with XLR and 1/4" jack connections. A special “one cable” in/out 1/4"
TRS jack has also been provided to allow the use of a standard 1/4" stereo cable to directly connect the CEL-2A to an
insert jack of a mixer.
Soft-knee topology is used for the compressor and expander functions to provide smooth transition curves. (When the
circuits become active‚ the gain change is phased in rather than instantaneously applied.) This causes the dynamic
changes to be less obvious and more aesthetically pleasing as well as being easier to adjust for the desired result.
The “downward” expander section has threshold and ratio adjustments to allow it to be used for noise reduction (slight
ratio) or a gate (high ratio). An LED lights when it is active. The compressor has attack and release controls in addition to
threshold and ratio controls for complete versatility. Any level lost due to compression can be made up by the gain
control. The limiter is an infinite ratio compressor that keeps the output from exceeding a level set by its threshold
control and has only one adjustment. It is totally independent of the compressor’s settings and can be used to stop
peaks from getting through when only mild compression (a low ratio setting in the compressor section) is desired. It has
its own LED to indicate when it has been activated.
Each section (expander‚ compressor or limiter) can be set so that it is disabled either by a threshold or ratio adjustment.
A side-chain insert (with its own enable switch) in the detector path allows manipulation or replacement of the detector
signal. Built into the side-chain are two selectable filters: a low-cut filter which reduces low frequency modulation from
the detector path and a “de-ess” filter‚ which will assist in removing sibilance (overstressing of the s‚ c and kconsonants).
These functions can be used simultaneously‚ either by themselves or with an external signal applied at the rear jack.
A dual-mono/stereo link switch sums the RMS detected signal levels of each channel together to accurately represent
the stereo signal’s amplitude. This voltage is used to control both VCAs. In this mode‚ only the controls associated with
Channel A function. The gain meter of Channel B follows Channel A’s.
There is a twelve-segment LED array that shows the amount of gain reduction and a ten-segment array to indicate either
the output or input levels. By watching the gain reduction meter and the output meter‚ adjustments are readily apparent
and easy to set.
A bypass switch disengages all functions and passes the input signal to the output without processing it. It is configured
to allow the unit to be used as an unbalanced to balanced converter even when bypassed‚ so power is always required.
Please read this guide carefully to ensure your personal safety as well as the safety of your equipment.
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