Inputs; Input Pinouts; Balanced Inputs; Unbalanced Inputs - QSC PLX 1804 User Manual

Inputs

Each channel has a balanced XLR (female) and 1/4-inch TRS input. The XLR and TRS
connectors for each channel are wired in parallel and can be used for "daisy chain-
ing" an input signal to additional amplifiers.
The input impedance is 20k ohm balanced or 10k ohm unbalanced. Both XLR and TRS
inputs are connected with standard cables and can be changed quickly. Pinouts are
marked on the rear panel. Do not attempt to connect more than one input signal to a
given channel.
Balanced connections are recommended to reduce AC hum and interference, espe-
cially with long cable runs. Unbalanced connections may be suitable for short cables.
The signal's source impedance should be less than 600 ohms.

Input Pinouts

Balanced inputs: Connect to the plug as shown.
XLR
TRS
Unbalanced inputs: Connect to the plug as shown. If using an XLR connector, Pin 3
and pin 1 must be connected with a jumper as shown. If using a TRS connector, the
ring and sleeve must be connected with a jumper. If a TS connector is used, the
sleeve will provide the "jumper" when inserted into the input jack.
XLR
TRS
TS
Input connectors and pinout
chart (PLX1802 shown)
PLX 1104 and PLX 1804 models can parallel the input
signal to both channels by using a jumper from one
channel to the next:
•Connect the input signal to either of Channel 1's
input connectors.
•Connect a jumper from Channel 1's unused con-
nector to either of Channel 2's input connectors.
TRS to TRS jumper from
Channel 1 to Channel 2
EN
Input signal
7