AA-series Audio Amplifiers Manual for DVC-AO Applications —
P/N 52526:B 8/13/2019
17
Wiring Multiple Audio Amplifiers
Amplifying Audio Messages
When finished installing all amplifiers and associated circuitry, adjust the audio gain as follows:
1.
Locate the Audio Gain Rotary Switch on AA-30 (Figure 3.6) or AA-100 and AA-120 (Figure 3.10).
2.
Use a small common screwdriver to turn the Audio Gain Rotary Switch until the Normal Level LED and Incorrect Level LED are
properly adjusted as shown in Table 3.3.
3.8 Wiring Multiple Audio Amplifiers
3.8.1 Two Primary AA-30s Without Backup
Figure 3.12 shows the use of two AA-30s without backup and Table 3.4 lists the wiring components used.
•
The speaker circuits on the first AA-30 share 30 watts from that AA-30; the speaker circuits on the second AA-30 share 30 watts
from that AA-30.
•
To use high-level audio (25 Vrms output) with four-wire supervision, cut resistors R8 and R9 on the AA-30 (Figure 3.5).
•
This wiring diagram applies to AA-30 audio amplifiers. Connections to plugs P1, P2, P4, P5, P6, P9, and P10 are identical.
Typical wiring of two primary AA-30 audio amplifiers without using a backup amplifier. This sample shows how to connect to speaker
circuit control modules within cabinet, using Cable 75109:
Audio Level
Normal Level LED Incorrect Level LED
Properly Adjusted
ON
OFF
Adjusted too Low
OFF
ON
Adjusted too high
ON
ON
Table 3.3 Adjusting the Audio Level
NOTE:
70.7 Vrms speakers require the 2 watt, 4.7K end-of-line resistors (P⁄N 90224) supplied with the AA-100 Audio Amplifier in place of
the resistors supplied with the speaker-control devices. Systems configured for 70.7 Vrms operation must be wired as Class B.
NOTE:
If not using Class A low-level audio return, an R-470 resistor assembly may be installed across P3, pins 4 and 5 of the last directly
connected device on the low-level audio riser; this may help to calibrate the audio amplifier.
Item
Supplied with
Part Number
Low-level audio cable
AA-30
75110
25-volt audio cable
AA-30
75109
Table 3.4 Wiring Inventory
Second AA-30
First AA-30
To Speaker Circuit
Control Modules
inside cabinet
(e.g. XP6-C, FCM-1)
Cable 75109
Optional
Class A
Audio
Return*
(Low-Level)
vo
ice
-aud
si
g-
no
ba
DV
C
AO.w
m
f
DVC-AO Outputs
1, 2, 3, or 4
(See DVC Manual for details)
Optional
4-Wire
Supervised
Return
(High-Level)
Optional
4-Wire
Supervised
Return
(High-Level)
To Speaker Circuit
Control Modules
inside cabinet
(e.g. XP6-C, FCM-1)
Cable 75109
Cable
75110
Unamplified
low-level audio
(Twisted-pair,
14-18 AWG)
Note: Cables must enter from top of the plug.
*Note:
If not using Class A low-level audio return, an R-470 resistor assembly may be installed across P3, pins 4 and 5 of the last
directly connected device on the low-level audio riser; this may help to calibrate the audio amplifier.
Figure 3.12 Wiring Two AA-30’s Without a Backup Amplifier
