PreSonus MP20 - Manual (Page 10)

CONTROLS & CONNECTIO NS
10
other devices requiring continuous power through the XLR input. This power is
supplied at a constant level allowing use of both inputs simultaneously for
condenser mics without any degradation of audio quality.
PIN 1 GND
PIN 2 +48v
PIN 3 +48v
XLR connector wiring for Phantom Power
Phase Reverse Switch allows the user to invert the polarity of the XLR
connector by switching pins two and three. The inversion of the pins of the
XLR connector may be necessary to alter the audio phase of two like
microphones to compensate for phase cancellation. It may be required that
the wiring of a cable’s XLR connector be switched to successfully utilize
Phantom power.
-20 dB Pad provides -20 decibels of attenuation with the push of a button.
This is a very useful feature for rapidly reducing the level coming into the MP20
and thus preventing the input signal from over-modulating (distorting) the input.
This may occur due to high output level from a microphone or line device.
Padding the input serves to provide increased “headroom” for the operator.
80 Hz Filter. The MP20 has an eighty-hertz filter that is activated by
engaging the switch on the front panel. This filter (often referred to as a
RUMBLE filter) is useful for eliminating extraneous low-end information from
the signal being amplified. Frequencies from eighty hertz and below are cut
from the incoming signal. This feature is useful in eliminating low frequency
noise such as air-conditioning rumble or for reducing the sound of footsteps or
other types of vibrations from being transmitted through the microphone stand
into the microphone.
Gain. This control provides 60dB of gain. The amplifier has inherent gain of