Audio Amplifiers—Audio Amplifiers (AA-30) 9
The Audio Gain Level multi-position rotary switch allows you to adjust
the gain of the audio output signal to compensate for audio line losses.
After you have made the correct adjustment, the AA-30 Audio Amplifier
produces its maximum rated output power at 25 VRMS. After installing
all of the AA-30 amplifiers, follow this procedure:
Use a small slotted screwdriver to position the rotary switch until the
Normal Level LED on the AA-30 is lit and the Incorrect Level LED turns
off. Once this is achieved, the audio gain is properly adjusted. See the
figure below.
Speaker Trouble LED
A n open c irc uit c o nd ition in th e 4- w ire s pe ak e r loo p.
Am plifier Trouble LE D
Lo s s o f th e a u dio inp u t s ign al o r troub le in the a ud io in or aud io
out c irc u itry .
Battery Trouble LE D
T he s ec on dar y (D C ) p ow er s our c e h as fallen be lo w a s ufffic ien t
v oltag e lev el.
Brownout LE D
T he prim ary (A C ) pow e r s ou rc e ha s fa llen b elo w a s uffic ient lev el.
N ote: D uring a c om plete lo s s of A C , no L E D s w ill light o n th e A A -30 .
Incorrect Level LE D
D ur in g n orm al (no n-alarm ) c onditions , th is LE D in dic ates th at
the A A -3 0 is out of ad jus tm ent. W h en th is LE D is o n a nd the
N o rm al Lev el LE D is o ff, th e a udio le v el has bee n adjus te d to o
low . W he n b oth this L ED an d the N orm a l Le v el L ED a re o n, the
au dio lev el h as bee n ad jus ted too hig h.
Norm al Level LE D
D ur in g n orm al (no n-alarm ) c ondition s , w h en this g reen LE D is
on an d the Inc orr ec t Lev e l LE D is o ff, the A A -3 0 is ad ju s ted
pro perly a nd op eratin g c o rrec tly .
FFCC08
A u dio G ain S w itch
P3
P1
P10 P9
P1
P2
P6
P7
P4
P5
Figure 4: Adjusting the Audio Gain
Note: When the AA-30 is operating on secondary power, no LEDs light
in order to conserve power.
Adjusting the
AA-30 Audio
Gain Level
