L-Acoustics LA8 Maintenance Manual page 14

LA8
AMPLIFIED CONTROLLER
MAINTENANCE MANUAL – LEVEL 1
VERSION 2.0
Issue
Noise
Level loss
Distorted sound
LA8_MM1_E N_2.0
Sound (continued)
Possible causes
1. gain value too high on the
controller
2. output gain value too high
on the audio source
3. switch to the analog
fallback mode with wrong
AES/EBU input gain value
4. wrong preset selection
5. audio source cable
incorrectly plugged
6. audio source cable
damaged
7. wrong settings on the
audio source
8. audio source failure
9. loudspeaker plugged into
the wrong output
connector
10. loudspeaker cable
incorrectly plugged
11. loudspeaker cable
damaged
12. loudspeaker damaged
13. mains failure
14. other cause
w w w . l - a c o u s t i c s . c o m
Inspection procedure / Diagnosis
Set an appropriate gain value on channels OUT1 to
OUT4.
If the AES/EBU input mode is selected, set an
appropriate AES/EBU input gain value.
Set an appropriate output gain value on the audio
source (refer to the third party documentation).
Set an appropriate AES/EBU input gain value and
inspect the digital audio source for failure.
Reminder: A digital audio source can meet the
following failures: no clock, loss of lock, invalid
audio (validity bit), CRC error, bipolar encoding
error, data slip.
A validity bit at non-audio value will not trigger the
automatic fallback. Instead the signal will be muted.
Select a preset in accordance with the loudspeaker
system connected to the outputs.
Unplug the XLR cable and plug it again on the audio
source and the controller.
Verify with your installer if ground loops can occur.
Replace the XLR cable.
Set appropriate parameter values on the audio
source (refer to the third party documentation).
Inspect the audio source for failure.
Plug and secure each PA-COM
cable into the loudspeaker and the corresponding
output connector on the controller.
®
Unplug the PA-COM or SpeakON
it again on the audio source and the controller.
Verify with your installer if ground loops can occur.
®
Replace the PA-COM or SpeakON
If only one loudspeaker is connected, inspect it.
Otherwise, go to next step.
Inspect the mains.
®
Contact L-ACOUSTICS .
® or SpeakON ®
®
cable and plug
®
cable.
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