ADA-21
Doc. No. – 13911
Page 2 of 3
AUDIO CONFIGURATIONS:
The source and destination audio equipment must be evaluated to determine if they are Balanced or
Unbalanced. After determination is made, refer to the drawings provided to select the proper audio
configuration. The outputs can be any combination of balanced or unbalanced.
Balanced In to Balanced Out
Balanced In to Unbalanced Out
Vout = Vin
Vout = 0.5 Vin
Unbalanced In to Balanced Out
Unbalanced In to Unbalanced Out
(-) Input Grounded; Vout = Vin
Vout = 0.5 Vin
(-) Input Floating: Vout = 0.75 Vin
The input to output level comparison provided in the figures above, assumes the outputs are terminated
into a 600
Ω
load.
FRONT PANEL:
The adjustments and indicators on the front panel (Figure 3) can be accessed through the slots provided
in the frame in which the ADA-21 is installed. When mounted within the SS-2100 Series frames, it will be
necessary to remove the front panel of the frame to gain access to these items. Factory settings of the module
provide unity gain, maximum common mode rejection, and a bandwidth of 100 kHz.
Gain control is achieved by adjustments to S01and R102. S01 provides adjustment of the gain in
increments of 6dB, while R102 provides fine adjustments of +/- 3dB. The positions of S01 make the following
adjustments to the gain level of the circuit - = OFF, 1= -6dB, 2= 0dB, 3= +6dB, 4= +12dB, 5= +18dB and 6=
+24dB.
Figure 3: Front Panel Gain Adjustment
+
C
-
IN
OUT
+
C
-
+
C
-
+
C
-
ADA-21
+
C
-
IN
OUT
+
C
-
+
C
-
+
C
Open
ADA-21
+
Gnd
IN
OUT
+
C
-
+
C
-
+
C
-
ADA-21
+
Gnd
IN
OUT
+
C
-
+
C
-
+
C
Open
ADA-21
S01
R102
3
1
2
4
5
6
