97-7224006_3-31-15
Information subject to change
9
7224 OPERATOR’S MANUAL – SECTION 2
2.5
Connecting the Input Signal
The signal is connected to the amplifier through
a “SIM (Specialized Input Module) Card” located
on the amplifier back panel (see
Figure 2.4
). The
standard SIM card includes both an Unbalanced
Input BNC jack and a Balanced Input “WECO” ter
-
minal block connector, an Input Select switch, and
an Interlock – I/O Connector. See the
Applica
-
tions
section for information on using the Interlock
– I/O Connector.
Position the
Input Select
switch to the left to
select the Unbalanced Input connector and to the
right to select the Balanced Input connector. Note
that
when the Input Select switch is in the right
position, both Unbalanced and Balanced Input
connectors are enabled.
IMPORTANT: The Input Select switch also func
-
tions as a Ground Lift switch for the Unbal-
anced Input connector. If circulating currents/
ground loops/60-Hz Hum occur when using
the Unbalanced Input, move the Input Select
switch to the right to lift the ground on the con-
nector.
Figure 2.4 – Closeup of SIM card
Figure 2.5 – Wiring for Unbalanced or Balanced
Input Connector
Connect your input signal to the amplifier’s unbal
-
anced or balanced input connector as shown in
Figure 2.5.
Use cables that are high quality and
shielded to minimize noise and to guard against
possible feedback.
