User guide
Program Audio
The selected audio input is routed to the program audio output according to the switcher 
mode. The input LED selected for program audio output blinks.
Program Audio Selection
Single switcher mode
In single switcher mode, audio from the selected input is routed to the program audio 
output. If combine mode is active, when a DVI input is selected, DVI audio is available on the 
HDMI audio output and the program audio output. 
Separate switcher mode
In separate switcher mode, the selected audio input from only one of the four input groups 
is routed to the program audio output. The selected input is indicated by a flashing input 
LED and is always the last input selected. The selected input LEDs of the other three groups 
are steadily lit.
If combine mode is active, when a DVI input is selected, DVI audio is available on the HDMI 
audio output and the program audio output.
1
MODE
2
SINGLE
1
SEPARATE
2
COMBINE DVI/HDMI
1
2
1
2
3
MUTE
MPS 409
DIGITAL MEDIA PRESENTATION SWITCHER
MUTE
VIDEO INPUTSHDMI INPUTS
MIC PROGRAM AUDIO
DVI INPUTSVGA/YUV INPUTS
CONFIG
EXEC
MODE
LED
Lit
LED
Blinking
LED
Lit
LED
Lit
Figure 16. Program Audio Selection (HDMI Program Audio Selection Shown)
Program Audio Breakaway
Both separate and single switcher modes provide audio breakaway which allows routing of 
the audio signal from any input to the program audio output independently from the video 
signal. It is available via software control only. See Program Audio Breakaway on page 23 
Program Audio Volume Control 
Using the front panel volume control knob, the user can increase or 
decrease program volume. The adjustment of program volume has 
no effect on the Mic volume so program audio can be muted while 
the Mic input is still active. The program audio volume has a range 
from 0-100 allowing the product to be controlled with a MediaLink 
controller. The associated LEDs light from bottom to top with 
increasing volume.
Program Audio Mute
The Program Audio mute button toggles the audio on and off. The indicator LED to the 
right of the button lights red when program audio is muted. Press the mute button again to 
unmute the output. 
Changing the audio input selection does not unmute the program audio output.
Changing the program audio control knob unmutes the program audio output.
NOTE:  Program audio mute does not mute the microphone input. 
1
MODE
2
SINGLE
1
SEPARATE
2
COMBINE DVI/HDMI
1 21 2 3
MUTE
MPS 409
DIGITAL MEDIA PRESENTATION SWITCHER
MUTE
VIDEO INPUTSHDMI INPUTS
MIC
PROGRAM AUDIO
DVI INPUTSVGA/YUV INPUTS
CONFIG
EXEC
MODE
MPS 409 • Operation 15










