Extron Electronics MPA 181T User Guide - Manual (Page 13)

MPA 181T • Installation and Operation MPA 181T • Installation and Operation
Installation and operation, cont’d
4/8 OHM
70V
+ -
COM 70V
COM 70V
4/8 OHM
70V
+ -
+
COM 70V
4/8 ohm output 70 volt output
Figure 2-9 — Output speaker wiring
The 70 volt output and the 4/8 ohm output cannot
be used simultaneously.
Front Panel Features
BASS LEVEL TREBLE
MINI POWER AMPLIFIER
MPA 181T
ON
OFF
LIMITER
2 3
1
Figure 2-10— MPA 181T front panel
1 Power LED — A green LED lights to indicate that the unit is
receiving power.
2 Limiter toggle switch — When the limiter is switched to “On”,
the MPA will automatically reduce the level to prevent the
amplifier from clipping.
3 Potentiometer adjustments — These three potentiometers
optimize level, bass, and treble adjustments.
Setting Up the MPA 181T Amplifier
When setting up volume control, ensure that the projector
output is set to variable out. Consult the projector’s user
manual for detailed instructions on its calibration.
To adjust the MPA 181T input level, bass, and treble, do the
following:
1. If connecting to a projector, ensure that the volume on the
device is at its lowest point, then adjust the level of the
MPA 181T fully counterclockwise.
2. Set the projector volume to its maximum volume level.
No sound should come out.
3. Return to the MPA and raise the level until sound
distortion occurs, then lower the level slightly until any
distortion disappears. This setting ensures that, whatever
the projector volume setting may be, no clipping occurs.
4. Adjust bass and treble to preference.
Remote connector wiring
Options for remote control include the Extron VCM 100 and
VC 50 volume controllers. Third party 10k potentiometer
volume controllers can also be connected to this port.
As shown below, Pin 1 is 10 VDC reference voltage. Pin 2 is
volume control DC voltage; range is 0 to 10 V, where 0 V is mute
and 10 V provides maximum volume. Pin 3 is ground.
All nominal levels are at ±10%.
VO
L /
MUTE 10V
REMOTE
Red
Black
Ground
Extron
STP 22
Cable
VOLUME
VCM 100
MUTE
VOL/MUTE
10V
3 2 1
Figure 2-11— Pinout diagram for VCM 100 MAAP
remote connector
2-11 2-10