SoundPlus
®
Infrared Listening System
6
Audio Connection
Microphone Input:
With the modulator DIP switches set for microphone input, the 3-pin XLR jack accepts balanced microphones. Power
for condenser microphones can be selected by DIP switch. The minimum input level is 100uV and the maximum level
is 90 mV.
XLR Line-Level Input:
With the modulator DIP switches set for line-level input, the 3-pin XLR jack accepts balanced line-level audio inputs.
The minimum input level is 21mV and the maximum level is 10V.
1/4" TRS Line-Level Input:
The 1/4" Tip/Ring/Sleeve (TRS) jack can accept only a balanced or unbalanced line-level input. A 25 V, 70 V, or 100V
speaker line can be connected to the balanced line input using an appropriate attenuator. “T” pads made with
resistors yield better fidelity than speaker matching transformers.
Figure 5: Audio Connection
BALANCED LINE USING 3–PIN CONNECTOR
IN PHASE
1
2
3
3 PIN CONNECTOR
A108
UNBALANCED LINE USING 3–PIN CONNECTOR
1
2
3
3 PIN CONNECTOR
A105
BALANCED LINE USING 1/4" CONNECTOR
IN PHASE
A106
UNBALANCED LINE USING 1/4" CONNECTOR
A107
Features and Controls
Figure 6: Features and Controls (MOD 232 Rear)
A254
COMPRESS CONTROL
2:1 SETTING WILL
INCREASE TRANSMITTED
AUDIO UP TO 30 dB
DURING PERIODS OF
LOW LEVEL SOUND.
INPUTS MIXED
INDICATES CHANNEL
A AND CHANNEL B
ARE MIXED AND
TRANSMITTED
BY CHANNEL A.
CHANNEL B IS OFF.
STEREO LED
INDICATES
STEREO MODE.
AUDIO LEVEL
CONTROLS
POWER SWITCH
TURNS THE MODULATOR
ON AND OFF. THE WALL
MOUNTED POWER SUPPLY
STAYS ON AT ALL TIMES.
LEVEL INDICATORS
INDICATOR SHOWS
AUDIO LEVEL IN 3dB
INCREMENTS.
IR LED
FOR TESTING
RECEIVERS.
PHONE SWITCH
SELECTS CHANNEL
A OR B AUDIO
WHEN NOT IN
STEREO MODE.
PHONE JACK
1/4” PHONE JACK.
MONITORS CHANNEL
A OR B STEREO AUDIO
DEPENDING ON
POSITION OF PHONE
JACK SWITCH, AND
MODE OF OPERATION.
POWER ON
INDICATOR
CARRIER (CXR) LEDs
INDICATES SELECTED
FREQUENCY, FLASHES
TO INDICATE A FAULT.
