MTI DOC 91743-A1
DESCRIPTION
The MTI 91743 Digital Amplifier is a cost effective solution for intercom applications. The 91743
communicates with the intercom master (i.e. touch screen computer or handheld device) over a
standard Ethernet connection. The amplifier is designed to connect to a 25V intercom system. The
digital amplifier also supports up to a 60W paging amplifier interface. In the standard MTI
Intercom system, the 91743 connects to the MTI Intercom termination boards (81129/81229) via
the speaker buss. See Figure 3 for the typical hookup for the 91743 digital amplifier.
The 91743 Digital Amplifier has two LED indications on the front panel. After the boot sequence,
the green LED will flash every second. When the amp is in talk mode, the red LED will be solid
on. The red LED will flash every second when in page mode.
Primary volume adjustment can be achieved remotely using MTI ProVision software. If additional
receive volume adjustment is needed, the potentiometer on the front panel can be used.
ELO
DATA CONVERTER
+12V
COM
D1
D2
CLK
C
H
A
N
1
+12V
COM
D1
D2
CLK
C
H
A
N
4
C
H
A
N
5
CLK
D2
D1
COM
+12V
C
H
A
N
8
CLK
D2
D1
COM
+12V
+
1
2
V
C
O
M
H
G
N
D
NETWORK
+12V
COM
D1
D2
CLK
C
H
A
N
3
CLK
D2
D1
COM
+12V
C
H
A
N
7
+12V
COM
D1
D2
CLK
C
H
A
N
2
CLK
D2
D1
COM
+12V
C
H
A
N
6
MTI PN
91620
C
O
M
P
W
R
HGND
LED
A
-X
5
A
-X
6
A
-X
7
A
-X
6
O
n/O
ff
Da
y
/Ng
t
A
U
D
1
A
U
D
1
A
U
D
2
A
U
D
2
S
H
L
D
S
H
L
D
CAL
L
COM
7
M
T
I P
N
511
2
9
B
D2
CLK
COM
D1
+12
6
5
4
2
3
1
0
7
6
5
4
3
2
1
0
M
TI
P
A
R
T
N
O.
5
1
2
2
2
D1
D2
C
COM
+12
+24
COM
COM
24 COM
M
TI
P
N
5
1
1
5
5
A
EMBEDDED CONTROLLER
NETWORK
MTI PN 91695-1
V
I
N
C
O
M
LED
ON
PORT
COM
Figure 1: Sample MTI control system
1
