dbx 1046 - Input;Output Meter Switch; Output Gain Control; Bypass Switch; PeakStopPlus Level Control

5Operating Controls
Input/Output Meter Switch-ThisswitchselectsthesignalformeteringbytheINPUT/OUTPUTLEVELMETER.
The switch lights indicating the input signal is currently being sent to the meter. When the switch is in the out
position, the output signal is selected for metering, and the switch will not be illuminated.
Output Gain Control -Thiscontrolsetstheoutputgainofthecompressor.Itcanbecontinuouslyadjusted
between-20dBand+20dB.Usethiscontroltocompensateforsignallevellossduetocompressionandto
adjustthenominaloutputleveloftheunit.
Bypass Switch - This switch bypasses the unit completely, “hard-wiring” the input directly to the output, and
the signal is not processed in any way. The switch will light indicating that the unit is currently bypassed.
PeakStopPlus™ Level Control - This control sets the level to which the output signal is reduced whenever
itexceedsthislevel.Itcanbeadjustedbetween+4dBuand+22dBu(OFF).ThisPeakStopPlus™limiter
uses a propietary dbx two-stage limiting process. The first stage is the Instantaneous Transient Clamp™
which clamps the signal with a soft logarithmic clamp function. This logarithmic function assures that the
signalwillnotexceedthelevelsetbythePeakStopPlus™LEVELcontrolbymorethan2dBtypically,and
that it will not introduce harsh artifacts. The second stage is a unique program limiter featuring Intelligent
PredictiveLimiting™.Itsfunctionistomonitortheinputsignalandintelligentlypredicttheamountofgain
reduction needed to keep the output signal below the ceiling set by the Instantaneous Transient Clamp™.
ThePeakStopPlus™limitermustcomeaftertheOUTPUTGAINcontrol.IftheOUTPUTGAINissettoohighas
comparedtothePeakStopPlus™LEVELcontrol,continuouslimitingcanoccur.WhilePeakStopPlus™istypically
used as a protective function, creative effects can be achieved by intentionally driving the signal into heavy
PeakStopPlus™limiting.GreatcarehasgoneintothedesignofthePeakStopPlus™limitertokeepitacoustically
transparent. Appropriate use of it can protect your gear while keeping the signal free of artifacts.
PeakStopPlus™ Threshold (+) LED Indicator-ThisLEDilluminateswhentheoutputsignalexceedsthelevel
setbythePeakStopPlus™LEVELcontrolindicatingthatPeakStopPlus™limitingisoccurring.
Figure3illustratestheprotectiveactionofthePeakStopPlus™limiter.Thesignalwiththethinlineweight
represents an unaltered input signal. As you can see, peaks of the input signal exceed the clamping level. The
signal with the heavier line weight represents the output signal. The peaks of the input signal which exceeded
the clamping level are not allowed to exceed this level at the output. This instantaneous protective action is
invaluable for driver protection in speaker systems and for digital recording where it is desirable to record as
“hot” as possible, while still avoiding the disastrous result of running out of headroom. Following this clamping
action,IntelligentPredictiveLimiting™takesover,typicallywithin5ms,aslongastheinputsignalcontinues
toexceedthePeakStopPlus™threshold.Thisprogramlimiterquicklyattenuatestheinputsignaltoalevel
safelybelowtheclampinglevel,typically2dBlowerthantheclampinglevel.ThePeakStopPlus™levelcontrolis
calibrated to this lower level, so if an absolute ceiling is required, set the level 2 to 3 dB below the front panel
setting.
TheattackandreleasetimesoftheInstantaneousTransientClamp™arezero,whiletheIntelligentPredictive
Limiting™ attack and release times are program-dependent. That is, for larger excursions over the threshold, the
attacktimespeedsup,andforsmallerexcursionsoverthethreshold,theattacktimeslowsdown.Similarly,for
largeexcursionsoverthethresholdwhichcausemorePeakStopPlus™gainreduction,thereleasetimeincreases
and is roughly proportional to the amount of gain reduction that occurred.