LIMITER Section
PEAKSTOP LEVEL Control and LED
This control allows you to set the maximum peak output level of the 166xs regardless of any
other control. PeakStop comes after the compression, gating and output gain circuitry; this
provides for an absolute limit to be put on the peak excursions at the output. PeakStop works
instantaneously; you can apply moderate amounts of dbx’s OverEasy compression and still be
protected from large transients, other short-term overloads and overmodulation.
PeakStop is a smooth well-controlled soft clipper whose behavior is sonically similar to the
gentleness of OverEasy compression; its clipping is much preferable to a power amp’s or
analog-to-digital converter’s. PeakStop rounds the corners of a peak rather than cutting it off
sharply. By making a signal’s leading and trailing edges curved instead of sharply angled, it
reduces the amount of higher odd-order, offensive-sounding harmonics that conventional hard
clipping causes.
The level at which PEAKSTOP is activated is adjustable from +0dBu to +20dBu. Note that small
signal excursions above the set value of PEAKSTOP are possible, to allow the rounding to
occur. Therefore, for applications where you must not exceed a given ceiling, set the
PEAKSTOP control 1dB to 2dB below the ceiling.
The PEAKSTOP LED illuminates whenever peaks attempt to exceed PeakStop level and are
reduced in amplitude. If the PeakStop LED illuminates when the PEAKSTOP LEVEL control is set
to +20dBu, the headroom capabilities of the 166xs are being exceeded and hard clipping is
occurring.
MASTER Section
STEREO COUPLE Button and LED
This button toggles the unit between stereo and dual mono operation. Press the STEREO
COUPLE button In for stereo operation where Channel 1 becomes the master controller for
both channels. All of Channel 2’s controls, buttons, and LEDs will be disabled (except for
Channel 2’s BYPASS, SIDECHAIN ENABLE, and CONTOUR buttons, and its GAIN REDUCTION
LEDs), since Channel 2 is the “slave.” Note that the detection circuitry senses the true RMS
levels of the combined signal, so it is unaffected by phase shifts (or other discrepancies)
between the channels. This ensures stereo compression without loss of imaging stability.
With the STEREO COUPLE button Out, the unit functions as two separate mono compressor/
gates, each with its own independent controls.
The STEREO COUPLE LED indicates that the 166xs is stereo-coupled.
Section 2
Getting Started
9
dbx 166xs
