dbx Pro 166XL Air Compressor User Manual


 
INTRODUCTION
Congratulations on choosing the dbx 166XL Compressor / Gate. The 166XL provides two channels of noise gating,
OverEasy® or classic hard knee compression and PeakStop® limiting to give complete control of signal dynamics to stu-
dios, sound reinforcement companies, musicians, or anyone who needs quality processing quickly and easily. We recom-
mend that you take a moment and read through the manual as it provides information that will assist you in using your unit
to its fullest potential. Features Include:
Stereo or Dual Mono operation of gating, compression and peak limiting.
OverEasy®/Hard Knee Selection - allows selection between our famous OverEasy compression curve and the classic
“Hard Knee” curve popularized by the original dbx 160, 161 and 162.
Expander/Gate Circuit - with variable release time and +15dBu maximum threshold.
Selectable Low Frequency Shelf (via Contour button) in the Sidechain Path - recommended when compressing mixed
program material to prevent low frequency energy from “punching holes” in the sound.
PeakStop® Limiting - provides control of maximum peak levels at the output of the 166XL regardless of any other
control. PeakStop comes after the compression, gating and other circuitry including the output gain, so it sets an
absolute limit for peak excursions before they reach the output.
True RMS Level Detection - senses the power in the program in a musical manner, much as human hearing does, giv-
ing results superior to peak or average detection.
Hardwire System Bypass Buttons on both channels - allow the audio to pass even if the unit is unplugged, and are
also useful for comparing the processed and unprocessed signals.
10-Segment LED Display for GAIN REDUCTION (up to 30dB).
Electronically Balanced XLR and 1/4” TRS Input and Output Jacks
Separate Sidechain Inserts - enables an outboard processor or signal to control compression or gating.
DC-Controlled Parameters - the signal does not pass thru any of the parameter controls. Instead a DC voltage controls
all functions; this eliminates any possibility of potentiometer noise developing over time.
INSPECTION
Verify that the 166XL package contains the following:
166XL Unit
AC Power Cord
Operation Manual
Registration Card
OPERATING CONTROLS
Front Panel
EXPANDER/GATE Section
Expander/Gate THRESHOLD Control and LEDs (BELOW/ABOVE):
Adjusting this control sets the level at which the gate will open and allow the signal at the input to pass through to the
output. Turning the knob fully counterclockwise (to OFF) allows the gate to pass signals unattenuated, effectively bypass-
ing the gate. Turning the knob fully clockwise causes the gate to attenuate input signals below +15dBu.
The two Expander/Gate LEDs indicate the relationship of the input signal level to the threshold setting. The red LED
lights when the signal is BELOW threshold, the green LED lights when the signal is ABOVE threshold.
Note: The 166XL’s expander/gate attack rate (which controls how fast the signal is restored after being attenuated) is internally set to be very fast - fast
enough to allow all of the transient at the beginning of a note, vocal or spoken word to come through.
2
®
PROFESSIONAL PRODUCTS
dbx 166XL COMPRESSOR / GATE