Instruction Manual

552 User Guide and Technical Information
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v. 1.4 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
nation the user gets the best of both VU and Peak metering by seeing the “loudness” of the signal
while observing peaks at the same time.
Peak Hold + VU
This is the default meter ballistics setting, it is a combination of Peak + VU and Peak Hold. The meter
simultaneously displays the Peak and VU information while holding peak values for two seconds.
Meter Reference Level
By default, a displayed value of 0 on the peak or VU meter will correspond to 0 dBu signal at the
main outputs of the mixer. In environments where the standard reference level is something other
than 0 dBu, the Meter Reference Level can be adjusted so that a displayed value of 0 dBu (peak or
VU) on the 552 meters will correspond to a higher level on the outputs of the 552. The Meter Refer-
ence Level can be adjusted in the setup menu. See the Setup Menu
Zoom Metering
Zoom Mode allows the user to quickly display the output levels in 1 dB increments from 0 dBu to
+20 dBu. Each LED represents a 1 dB change. While in Zoom Metering mode, the etched -30 LED is
re-assigned to 0 dBu, the etched -24 is actually +1 dBu, and so on. Press the Headphone Controller to
enter and exit Zoom Metering Mode. The blue Zoom LED indicates that the meter is in Zoom Meter-
ing Mode. Zoom Metering Mode can be disabled in the Setup Menu Function Metering Ballistics to
prevent accidental activation.
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Normal Resolution (etching)
Zoom Mode Resolution
Input Activity LED
Each channel has its own Input Activity LED located just above the Input Fader. The LED illumi-
nate in various colors and intensities to represent the signal level appearing at its respective input.
Green = pre-fade signal activity, yellow = pre- and post-fader limiter activity, red = pre- and post-
fader signal overload (peaking). Reduce the trim level control if the LEDs continuously illuminate
yellow or red. The Input Activity LED will flash yellow when the Input PFL is latched on and illumi-
nate solid red when the input is muted.
Headphone Peak LED
Like the Channel Peak LEDs, the headphone circuit also has a peak overload indicator. This LED is
useful because headphones can often overload before overloading the 552’s stereo output bus. Moni-
toring without a visual indication of headphone clipping can mislead the sound mixer into thinking
that the output or return feeds are distorted.