2.1 Rear Panel Connections
AC POWER Receptacle
This receptacle accepts an IEC-type power cord (as shipped with the unit). Plug the cord
into the unit and mains power. Note that the 166xs does not have a power switch. It is
recommended that the 166xs be “On” at all times. Power consumption is low. If you do not
plan to use the 166xs for an extended period of time, unplug it.
WARNING: Be sure to verify your actual line voltage is the same
as the voltage level printed below the AC power receptacle.
Connection to an inappropriate power source may result in
extensive damage which is not covered by the warranty.
Caution: Never remove the cover. There are no user-serviceable parts inside.
INPUT (Balanced) Jacks
The Tip/Ring/Sleeve phone jack and XLR-type jack are wired in parallel; either INPUT will
accept an audio signal for processing by the 166xs. The phone jack accepts a standard TRS
1/4” phone plug for a balanced input source, or a 2-circuit (Tip/Sleeve) 1/4” phone plug for
an unbalanced source. The XLR-type jack is wired pin 2 HOT (+), pin 3 COLD (-) and pin 1
GROUND.
NOTE: Only one input jack should be used at a time, except for “splitter” applications where
one input jack is used as an input and the other input jack is used as an output (see “Using
the SIDECHAIN INSERT” section on page 10). Since a given pair of channel input jacks (e.g.,
Channel 1 XLR INPUT and Channel 1 1/4” INPUT) are internally connected (TIP = Pin 2,
RING = Pin 3, SLEEVE = Pin 1), if one of the jacks is unbalanced, then the other jack will be
unbalanced. For example, if a 1/4” INPUT jack is used with a mono cable, and is therefore
unbalanced, the XLR INPUT jack will also be unbalanced (Pin 3 shorted to ground).
OPERATING LEVEL Switch
This switch selects between a -10dBV and +4dBu nominal operating level. When the switch is
in the in position, a -10dBV operating level is selected. When it is in the out po4dBu
is selected. A -10dBV operating level should be selected when interfacing with “semi-pro” or
low level equipment, while a +4dBu level should be selected when interfacing with “pro”
equipment. The switch simultaneously changes the operating levels for both the input and
output circuits. Note that the switch is slightly recessed to prevent accidental switching of
operating levels while plugging in or unplugging cables.
Section 2
Getting Started
4
dbx 166xs
Section 2 - Getting Started
