571
18
Troubleshooting
Chapter 9
There is no output signal:
Check the AC power connections to the
571.
Check input and output cables and
connections. Are inputs driven by
outputs, and outputs driving amplifiers?
Determine that there really is a signal
coming from the source and that it is
getting to the 571.
Are the loudspeakers and amplifiers
working?
Unit will not calibrate:
Are input levels normal?
Are the error LEDs coming on during
calibration?
Is the sensing mic(s) plugged in and
turned ON?
Increase SENSE 1 and/or SENSE 2 gain.
Music always plays too loud:
571 is being used for music, but was
calibrated with the F
ORMAT
(P
AGE
/M
USIC
)
switch in Page position. Change rear panel
F
ORMAT
(P
AGE
/M
USIC
) switch to M
USIC
,
then recalibrate.
Did someone turn up the level of the music
feeding the 571 after it was calibrated?
Did someone turn up the output gain trim
pot?
Unit seems to have no effect:
Check the R
ATIO
control. At 2:1, the gain
changes are
very
subtle. Turn the R
ATIO
control clockwise for more change.
Check the A
VERAGING
T
IME
control. When
this control is set other than fully counter
clockwise (1.2 sec), the unit does not
respond immediately.
Unit does not increase gain sufficiently at
high ambient levels:
You may be overloading the sense mic
preamps. Insert 15 dB pad and recalibrate.
P
AGE
/M
USIC
I
NPUT
E
RROR
LED flashing during
calibration:
Not enough signal level on either P
AGE
or
M
USIC
inputs.
S
ENSE
I
NPUT
E
RROR
LED flashing during
calibration:
Not enough signal coming from sense
mics. Try turning up the S
ENSE
G
AIN
trimpots.
Check sense mics and cables.
Hum or buzz in output:
Check input connector wiring (refer to
Appendix D).
Ground loop. Check related system
equipment grounding. Are all system
components on the
same
AC ground?
Distortion:
Check input signal. Is it already dis-
torted?
Line input signal may be too hot.
Page mic signal may be too hot.
Does the sound system have sufficient
power for the SPL that you are trying to
attain?
If you are using a high Max setting, you
may be overloading the input to your
amplifier. Reduce MAX setting. Is
something else clipping?
Are the amplifiers and speakers okay?
Check in BYPASS.
Noise (hiss) :
Check input signal levels, and level
control settings.
Check gain settings on downstream
equipment.
Is the input signal already noisy?
No audio:
Is the unit plugged in?
Is the unit in B
YPASS
mode?
