ADA-26A
Doc. No. – 13923
Page 1 of 3
ADA-26A AUDIO DISTRIBUTION AMPLIFIER
GENERAL:
The ADA-26A Audio Distribution Amplifier is designed to provide six (6) outputs from a single audio signal
source. The unit is compatible with either balanced or unbalanced audio signals on the input and outputs.
Outputs can be mixed between balanced and unbalanced configuration dependent on the requirement of the
destination equipment.
POWER:
The ADA-26A operates from an AC power source of 120VAC or 230 VAC at line frequencies from 50 Hz to
60 Hz. The unit is supplied with a line cord terminated with a three-prong grounded plug.
Internally the unit has bus voltages of +15Vdc and -15Vdc supplied by regulators U01 and U02 respectively.
An LED on the circuit board illuminates the front panel when both supplies are operating properly.
Circuit protection is provided by the externally accessible fuse on the rear panel. Refer to the specification
section for proper fuse value.
FRAMES:
The ADA-26A module is mounted within a stand-alone box. The all-metal enclosure provides desirable
shielding to external EMI/RFI noise sources.
Rack mounting requires the RMK-26 rack-mount kit. One RMK-26 rack-mount kit holds up to three of the 26
series units. Sigma provides various distribution amplifiers, signal generators and transcoding products in the
26 series.
CONNECTIONS:
Wiring to the module is performed via detachable screw terminal connectors (Figure 1).
INPUT: There is a single input on the rear panel of the unit (Figure 2). The INPUT is a high impedance
configuration. This allows the audio signals to bridge to other units. To ensure proper impedance matching it
may be necessary to terminate the outputs with a 600
Ω
load. For termination, it is recommended that a 600
Ω
,
1/2 watt resistor be placed between the (+) and (-) outputs. When multiple units have inputs bridged to the
same source, only apply the 600
Ω
resistor to the last unit in the line.
OUTPUT: There are six (6) outputs on the rear panel of the unit. Each output is designed to drive a 600
Ω
load.
Figure 1
AUDIO CONNECTOR
REAR PANEL CONNECTIONS
Figure 2
1
2
3
4
5
6
-
C
+
O P
U U
T T
S
FUSE
T125mA/T63mA
250V
ADA-26A
120/240V~
50/60Hz
12W
SIGMA ELECTRONICS, INC.
T
CAUTION
RISK OF
ELECTRIC SHOCK
DO NOT OPEN
I
N
P
U
T
-
C
+
-
C
+
-
C
+
-
C
+
-
C
+
-
C
+
