97-8004167 07-14-17
Information subject to change
9
7224 & 7226 OPERATOR’S MANUAL –
SECTION 3
Figure 3.3 – Connecting the Load
amplifier to any other model amplifier, power sup
-
ply, signal source, or other inappropriate load; fire
can result.
NOTE: The 7224/7226 amplifier comes with a
factory-installed 2.7-ohm, 2W, 5%, metal-oxide
resistor connecting the terminals marked “COM
and “CHASSIS GROUND” (see
Figure 3.2
). This
resistor should NOT be removed except when the
amplifier is being used as a Slave amplifier in a
Series multi-amp system.
WARNING: Removing
this resistor can cause dangerous output and/
or damage to the load.
3.2.2 Connecting the Outputs
Connection to the output of the amplifier is to a
3-position terminal strip with #8 screws. Wires
terminated with #8 ring terminals, tinned wires up
to 10GA in size, or bus bars with 0.18 in. (4.6 mm)
holes are recommended when connecting to the
output terminals.
Connect the load across the terminals marked
“OUTPUT” (positive) and “COM” (negative/
ground). The third terminal, “CHASSIS GROUND”
Figure 3.2 – Closeup of the Output Terminal Resistor
Figure 3.4 – Closeup of SIM card
can be connected to an external ground point such
as the rack chassis. See
Figure 3.3.
3.3 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 3.4
). The SIM
card offers the choice of BNC or “WECO” terminal
block input connectors.
The Input Select switch, located on the SIM mod-
ule between the input connectors, allows conve-
nient selection of balanced or unbalanced input
wiring and also can function as a ground-lift switch
for the BNC input connector. The Input Select
switch functions by connecting/ disconnecting the
inverting (–) pin on each input connector to the
amplifier ground through a 4.7-ohm resistor (see
Figure 3.5
). When the Input Select switch is in the
LEFT position, the shield on the BNC connector
