For sources that will run through Program A (this is the program shown in the top half 
of the Program Display which uses Effect 1 and Effect 2), connect to the A Left/Right 
(Front) input and output pair.  Sources running through Program B (this is the pro-
gram shown in the bottom half of the Program Display which uses Effect 3 and Effect 
4), connect to the B Left/Right (Rear) input and output pair.
Connection Diagram: Dual Mono In/Dual Mono Out, Dual Mono In/Ste-
reo Out, Stereo In/Stereo Out (x2)
Send 1
Return 1
2
2
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3
4
Once you have your connections made, you should refer to the Effect/Mix Routing 
section of the manual for understanding how the signal sources can be routed through 
each configuration’s programs and effects.
The MX400 ANd dIGITAL I/o
The MX400 is equipped with two digital inputs and outputs (S/PDIF A and B).  Each 
S/PDIF pair is the digital equivalent of analog input/output pairs A and B.  The digital 
outputs on the MX400 are always active and will always mirror their analog output 
counterparts.  This allows you to plug in an analog input source and have it be output 
as a digital stream.  
The MX400 has three options for input sources which are configurable in the System 
Menu: Analog Mono Left, Analog Stereo and Digital.  (Press the System 
button to access the System Menu; turn the Page/Select knob to scroll up and down 
the menu.)
 
Each input pair (A and B) can have different audio sources selected depending on your 
needs. While in the System Menu, use Knobs A, B, and C to change values.  As with 
all equipment that receives digital audio streams, when setting either Input Source A or 
B to Digital, the MX400 can no longer use its own internal clock source for the audio 
The MX400 and Digital I/O
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