Signal Levels - SoundCraft SM12 User Manual

Signal Levels

It is important to supply the correct input levels to the console, otherwise signal to
noise ratio or distortion performance may be degraded, and in extreme cases,
damage to the internal circuitry may result. Likewise, on all balanced inputs avoid
sources with large commonmode DC, AC or RF voltages, as these will reduce the
available signal range on the inputs. Note that 0dBu = 0.775V RMS.
The microphone inputs are designed for use with balanced low impedance (150 or
200 ohms) microphones.
Caution!
DO NOT use unbalanced microphones or battery powered
condenser microphones without isolating the +48V phantom power:
degraded performance or damage to the microphone may result.
The sensitivity of the XLR inputs is variable from -2dBu to -70dBu and +10dBu to
-20dBu in two ranges (for +4dBu at the Mix outputs). The maximum input level is
+28dBu on the lower sensitivity range, and +18dBu on the higher range.
The Hi-Z inputs have a sensitivity variable between +10dBu and -20dBu. The
maximum input level is +30dBu.
The main outputs of the console (stereo mix, groups, wedge and mix and group
insert sends) are balanced at a nominal level of +4dBu, with a maximum output
level of +26dBu.
The input insert sends are balanced at a nominal level of +4dBu, with a maximum
output level of +26dBu.
All external inputs and mix and group insert returns have a nominal level of +4dBu,
and a maximum input level of +26dBu except the AFL/PFL external inputs which
are unbalanced at a nominal -2dBu, with a maximum input level of +20dBu.
Insert returns are balanced at a nominal level of +4dBu, and a maximum input level
of +26dBu.
Introduction 5