Front Panel Controls - Ashly MX-406 Operating Manual

Operating Manual -MX-406 Stereo Microphone/Line Mixer
4. FRONT PANEL CONTROLS
4.1 Input Gain
This three position switch sets the operating level of
the microphone and line input preamp . The corresponding
switch values -20db, -40dB, and -60dB refer not to the actual
gain, but rather to the expected nominal input signal strength .
Best signal to noise ratio is obtained with higher
gain settings . It is therefore desirable to set the gain control
as high as possible while still leaving 20dB of headroom for
signal peaks . Line level inputs (1/4" jack) will likely use a
setting of -20dB, while mic inputs generally require a setting
of -40dB for close mic applications, and -60dB for quieter
signals . If a channel's clip LED is blinking, first turn down
that channel's level control . If the clip LED is still flashing,
turn down the input gain .
4.2 Clip
Input Clip LEDs are peak sensitive and monitor all
critical points within the input channel . The clip LED turns
on whenever any portion of the audio path within the input
channel reaches a level 3 dB below actual clipping . Clipping
in the MX-406 occurs at +20dB .
4.3 Treble/Bass
This concentric knob is used for broad EQ changes
to each input channel . Channel EQ consists of a high shelf
control (treble) at 4KHz, and a 250Hz low shelf control (bass) .
EQ boost or cut is ±12dB .
4
4.4 Aux
The aux send is an additional level control used to send
signal from each input channel to monitors, an effect unit, or
another mix . The aux master output combines all six channel's
aux level signals . The aux control is factory set to pre-fader,
pre-EQ, but can be internally switched to post-fader, post EQ .
To make this change, refer the following procedure to a quali-
fied service technician:
Unplug the unit's AC power cord from the outlet.
Remove the bottom cover which is fastened by seven 6-32
screws. Locate the 3 pin header labeled AUX at the middle of
the back edge of the front portion of the channel circuit board.
Remove the shunt bar from the "Pre" position indicated on the
circuit board legend and place the shunt on the "Post" position.
4.5 Level and Pan
This concentric knob adjusts the level and stereo
position of each channel . If a channel's level control is always
turned up to 9 or more, try increasing the gain first . Con-
versely, if the level control is consistently turned down to 1 or
less, decrease the gain setting first . Remember that the gain
setting should be set as high as possible while still allowing
20dB of headroom .
4.6 Stereo Line In
This control adjusts the level of the stereo line input
RCA jack on the back panel, as well as the 3 .5mm stereo line
in jack on the front panel . They can be used for tape, CD/
DVD, or MP3 player audio inputs, and can also be used for a
stereo effect return . Both inputs can be used simultaneously,
but there is only one level control . For expanding the channel