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www.rolls.com
DESCRIPTION
FRONT PANEL
LEVEL 1, 2, 3, and 4: Adjust the level of signal from the corresponding Mic Input.
PAN 1, 2, 3, and 4: Adjusts the relative Right/Left signal level to the mix bus.
SLATE MIC: When the Slate Button is pressed and held in, the sound at this microphone
is sent to the main outputs, along with a 20Hz sine wave signal.
SLATE BUTTON: Engages the Slate Mic.
COMP THRESH: Sets the level at which the compressor will
“
compress
”
or lower the
signal level.
1 kHz TONE: When pressed, this button sends a 1 kHz signal to the main outputs.
BATT TEST: When pressed, this button will indicate the approximate battery voltage on
the VU meters. Proper battery voltage will be indicated with the meters moving to the
red region of the fi eld. If the meters are below the red region, battery replacement is
necessary.
HEADPHONE LEVEL: Adjusts the level of signal from the Headphone Outputs.
HEADPHONE SOURCE SELECT SWITCH: When this button is OUT, the sound heard at
the Headphone Outputs will be that of the Main Output, when it is pressed IN, the
sound heard will be that of the Monitor Input.
HEADPHONE/EARPHONE OUTPUTS: 1/4
”
Tip-Ring-Sleeve and 1/8
”
(3.5 mm) Tip-
Ring-Sleeve jacks containing either the Main Output signal or Monitor Output signal
depending on the setting of the Headphone Source Select Switch.
OPERATION
INPUT CHANNELS
The inputs to the MX422 consist of four, full-featured microphone preamplifi ers.
Each channel has a wide gain range to accommodate nearly all signal types. The unit
accepts signals ranging from low-sensitivity ribbon and dynamic microphones to me-
dium level wireless and condenser mic outputs, up to the “hot” line levels.
The MX422 input channels can be used as wither balanced or unbalanced connec-
tions. When unbalancing - ground pin-3 to pin-1. There is no change in gain between
unbalanced and balanced connections into the MX422.
The AUX INPUT jack is provided for recording stereo sources such as CD players, MP3,
players, DVD, etc.
TRIM CONTROL
Like traditional mixing consoles, the MX422 microphone preamp gains are set via the
trim control. This control adjusts the input sensitivity of the channel input so that the
channel fader can be set to operate in a usable range. Once set, the trim is typically
kept at the set level and all mixing is done on the channel front panel Level control.
INDIVIDUAL CHANNEL LEVEL CONTROLS
While both the trim and channel Level controls adjust the gain of a given channel, the
Level is the primary channel volume control. The trim can be thought of as a
“
course
”
gain adjustment to be adjusted during setup, and the Level control is a “fi ne” gain
adjustment used while recording. With a properly set up trim control, the Level can be
set to a nominal level (around 12 O’clock) providing the maximum amount of variance
and headroom.
PHANTOM POWERING
The MX422 can provide up to 10 mA of current to each input at 48 Volts, suffi
cient for
the most power-hungry condenser microphones. The MX422 Phantom Power utilizes
a fi xed 48 Volts DC which is resistively applied to pin-2 and pin-3 of an XLR input con-
nector relative to pin-1 (there is no voltage diff erence between the signal on pins -2
and - 3; a dynamic microphone may or may not operate normally in the presence of
phantom power).
It is generally a good practice to turn off phantom powering when not using a con-
denser microphone as it can capacitively couple noise into the mic inputs with poor
mic cables. Also, be sure to turn off phantom powering when using ribbon micro-
phones since an improperly wired cable can permanently damage the microphone.
LOW-CUT FILTERS
Each channel of the MX422 features a switchable Low-Cut fi lter set at 100Hz. These
Low-Cut (sometimes called “High Pass”) fi lters are useful for removing excess low
frequency energy in audio signals. Wind noise is a common unwanted low frequency
signal and a low-cut fi lter is eff ective for reducing wind noise. For several audio ap-
plications engaging the Low-Cut fi lter is benefi cial since little usable audio information
exists below 100 Hz - especially for speech recording.
