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NOTE: If the effects loop is not used, the slide switch
should be in the OFF position.
Mounting
The SMA-40, 60 and 120 were designed for shelf or
rack mounting. Make certain the unit is not mounted
near heat sources or strong magnetic fields. Verify
control and terminal strip accessibility. The unit may
be rack mounted. Order the associated rack mount kit
SMA-RMK.
MIC Connections
These units provide connections for low impedance
balanced microphones. Connect the positive pressure
lead of the microphone (normally pin 2 of a standard
XLR connector) to MIC (+) terminal connection,
microphone shield to MIC COM terminal and the
negative pressure lead of the microphone to the
remaining MIC terminal connection as shown in Figure
3.
Telephone System 600 Ohm Page
Port Connection
When using these mixer-amplifiers with a 600 ohm
telephone system page port, connect page port Tip to
the TEL (+) terminal and connect page port Ring to
TEL-COM as shown in Figure 4.
NOTE: Interface devices are required when
connecting to outside C.O. Lines, PABX extensions,
or single line telephones.
Auxiliary Connections
High impedance auxiliary devices such as a tuner, tone
generator, etc. can be connected to the AUX input.
Phono jacks are provided at the rear of the amplifier for
each of the auxiliary inputs.
Speaker Cabling
When the 2 or 4 ohm output is used, standard two
conductor speaker wire can be used (18-20 AWG
determined by the load). If the 25 or 70V output is
used, two conductor shielded cable is recommended for
speaker connections. NOTE: When shielded cable is
used, the shield should be connected to the Ground
terminal located on the back of the amplifier.
Priority Override
To enable the cascading priority override feature,
install a wire strap on the two terminals marked priority
on the back of the amplifier (see Figure 3).
Amplifier Setup
During initial system set up, it is recommended that the
individual gain controls be set 1/4 turn clockwise
and the master volume control be set 1/2 turn
clockwise.
All connections should be made to the amplifier and
double-checked before the AC power cord is plugged
in. The power indicator will illuminate when the AC
power cord is plugged in and the power switch is in the
"ON" position.
OPERATION
These units provide two modes of operation, either
active mix or priority override.
When the amplifier is in the active mix mode signals on
all inputs are mixed and sent to the speakers. When the
priority input is selected, a signal on the MIC/TEL
input will override all other active inputs (See Table 1
for override sequence). The override is voice activated
and does not require the use of an external relay or
contact closure. The separate gain controls on the unit
allow adjustment of the volume levels of each input.
A clipping light is provided on the front of the unit.
This light will illuminate when the output signal
exceeds the power rating of the amplifier.
Table 1 - Override Sequence
Input
Mic 1/TEL
Mic 2/Aux 1
Mic 3/Aux 2
Mic 4 /Aux 3
NOTE: Level 1 is highest priority.
TECHNICAL ASSISTANCE
When trouble is reported, verify that AC power is
being supplied to the unit and there are no shorts or
grounds on cabling.
Assistance in troubleshooting is available from the
factory. When calling, you should have a VOM
available and be calling from the job site. Call (540)
427-3505 and ask for Technical Support or (540) 427-
6000 for Clarity 24-hour Automated Support.
3
Priority Level
1
2
3
4
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