PreSonus M80 - Manual (Page 11)

CONTROLS & CONNECTIONS
9
Phantom Power is available to each channel input of the M80. The 48 volts is supplied by
way of the XLR connector for condenser mics and any other devices requiring continuous power through
the XLR input. This power is supplied at a constant level allowing use of all eight inputs 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 M80 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 M80 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
reducing the sound of footsteps transmitted through the microphone stand into the microphone.
Gain
control provides 60dB of gain. The amplifier has inherent gain of 12dB thus delivering a total gain
possibility of 72dB.
2 . 3 M A S T E R C H A N N E L