Installation and Setup
AT-MX351 SmartMixer setup tips:
1.
Turn the Master level control to the minimum position. Proceed with steps 2-9.
2.
Set all Priority DIP switches and Manual mode switch to “down” position.
3.
Turn all four microphone Gain controls fully counterclockwise.
4.
Connect the power cord to the mixer and plug into AC outlet. Be certain the voltage
switch on bottom of unit is set for the voltage of the outlet you are using.
5.
Turn Power switch “on.” The mixer will perform a self-test and turn each microphone
“on” and “off ” consecutively.
6.
Connect a microphone to Input 1 and turn the Gain 1 control to the “nine o’clock”
position. The channel 1 LED will light if the microphone is operational.
7.
Adjust the Gain 1 control for proper meter indication when speaking into microphone
(peaks at 0).
8.
Plug in up to three other microphones and adjust each respective Gain control for proper
meter indication.
9.
Priority can be assigned to one or more microphones by moving the appropriate DIP
switch(es) to the “up” position. Any microphone(s) assigned in this manner cannot be
locked out by any other microphone.
10. “Manual” mode can be selected at any time by moving the right-hand DIP switch to the
“up” position. In this mode, the unit will behave like a conventional mixer (all automatic
functions are bypassed except for limiting and NOMA if selected).
11. Adjust the Master level control for desired output level. This control is at the last stage
in the mixer, and does not affect microphone gain, threshold setting, meter indication,
monitor or preamp outputs.
Priority Microphones and the Lockout Bus (Channels 1-4)
Once the Gain controls have been properly adjusted, an audio signal appearing in any channel
causes the lockout control bus to activate and the Lockout LED indicator to light. The Priority
Pre-select switches then determine whether or not a particular mic is affected by lockouts
caused by other mics: a channel Priority switch in the “down” position will allow lockout* of
its mic; the same switch “up” will not allow lockout of its mic.
* Note that any mic which is described as “locked out” or “off ” is really just being attenuated
by between 6 dB and 40 dB from the level otherwise determined by its Gain control setting,
sensitivity and placement. See the “Daisy-chaining Mixers” section on page 14 for further details.
There are basically three “modes” of priority pre-select automatic operation:
Mode 1... Priority Pre-select switches (1-4) Up
The Lockout indicator will come on with any audio input, but no mic will be locked
out…because none are connected to the lockout bus. (This mode is often called
“Free-for-all”…or sometimes “City Council”!)
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