SoundCraft MPM 20/2 - Manual (Page 13)

13
MONO INPUT CHANNEL
1 Mic Input
The MIC input accepts XLR-type connectors and is designed to suit a wide range of
BALANCED or UNBALANCED signals. Professional dynamic, condenser or ribbon
mics are best because these will be LOW IMPEDANCE. You can use low-cost HIGH
IMPEDANCE mics, but the level of background noise will be higher. If you turn the
PHANTOM POWER on (top right-hand side of the mixer) the socket provides a suit-
able powering voltage for professional condenser mics.
TAKE CARE when using unbalanced sources, which may be damaged by the phan-
tom power voltage on pins 2 & 3 of the XLR connector.
Unplug any mics if you want to use the LINE Input. The input level is set using the
GAIN knob.
2 Line Input
Accepts 3-pole 6.35mm (1/4") jacks. Use this input for sources other than mics,
such as keyboards, drum machines, synths, tape machines or DI’d guitars. The
input is BALANCED for low noise and top quality from professional equipment, but
you can use UNBALANCED sources by wiring up the jacks as shown in the ‘wiring up’
section, although you should then keep cable lengths as short as possible. Unplug
anything in the MIC input if you want to use this socket. Set the input level using the
GAIN knob.
3 High-pass Filter
Pressing this switch activates the high-pass filter. This reduces the level of bass
frequencies only. Use this in live PA situations to reduce stage rumble or ‘popping’
from mics.
4 Insert Point
The unbalanced, pre-EQ insert point is a break in the channel signal path, allowing
limiters, compressors, special EQ or other signal processing units to be added in the
signal path. The Insert is a 3-pole 6.35mm (1/4") jack socket which is normally
bypassed. When a jack is inserted, the signal path is broken, just before the EQ
section.
ONLY connect condenser microphones with the +48V powering OFF, and
ONLY turn the +48V powering on or off with all output faders DOWN, to
prevent damage to the mixer or external devices.