User Manual
10
RackPack: Premium Mic Pre
Mic Gain
With the Mic Gain control you can regulate the preamplification of the
microphone signal. It ranges from +12 dB to +80 dB. The input stage can
handle input levels of up to 10 dB. The value set with the Mic Gain con-
trol defines the output level equally for both Output 1 and Output 2.
When you set the Mic Gain you have to consider the type of microphone
that you are using (dynamic or condenser microphone) as well as its
sensitivity. The sensitivity of a dynamic microphone is at around 2 mV/
Pa whereas the sensitivity of a condenser microphone can be up to
20 mV/Pa. The result is a difference in output of 20 dB.
You should also consider the sound pressure level of the sound source,
the distance of the microphone to it and the acoustics of the room when
you set the preamplification.
About Leveling
Initially you should always deactivate the -10 dB button to have cor-
rect values displayed by the VU meter (see “-10 dB” on page 11). Now
turn up the Mic Gain control until the VU meter displays maximum lev-
els between 0 dB and +3 dB. At this level you don’t risk any overdrive
when you experience sudden and unexpected peaks in the level of the
source. Always remember that the VU meter only shows average values
and that a peak level can be much higher (up to +10 dB). If necessary,
turn on the PPM mode to see the actual peak levels.
Usually levels of around 0 dB and +3 dB are safe. If, however, you expe-
rience very high peaks already at minimum Mic Gain values (i.e. drums,
brass instruments), you can activate the PAD function (see “PAD”
on page 12). The input level is now reduced so that you can regulate
Mic Gain again in a useful range.
If you know in advance that the level will be very consistent you can
always turn up Mic Gain. In this case you can activate the -10dB button
to have more headroom in the display.
IMPORTANT: To exclude any audible distortion the OVL LED should
only light up shortly. It starts illuminating 3 dB before a potential over-
load, so first illumination does not indicate an overload, but that the
limit of leveling is reached. Avoid permanent illumination of the OVL
LED to exclude overloads (also refer to “Overload LED“ on page 13).
Control Elements
Mic Gain, About Leveling
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