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into the 4 vacant threaded holes in each corner of the underside of the m903.
For rack mount installation, the m903 chassis has a #10-32 threaded insert mounting hole on the bottom towards the back. Two
m903’s can be mounted side by side in a standard 1U rack tray. Use a #10-32 x 1/2” or a #10-32 x 3/8” machine screw. Do not use a
screw longer than 1/2”.
Powering up the m903
PoWer ConneCtionS
The disconnect device for the m903 system is the mains plug or the appliance coupler on the power supply cord.
The disconnect device must remain accessible and operable. The power supply cord supplied with the m903 must
be connected to a mains outlet with a protective earthing connection.
CHeCk line VoltaGe SettinGS
The iec power entry module has been set from the factory to operate at the voltage required for your part of the world. However,
it’s important to double-check this in order to ensure no damage will come to the unit if power is applied and the setting is incor-
rect.
line VoltaGe SeleCtor
To change the line voltage, remove the AC power chord from the power inlet then use a small screwdriver to pry the fuse carrier
out. Remove both fuses from the fuse carrier and replace with the proper value fuse from the fuse chart below. Carefully remove
the grey colored fuse holder and re-insert it into the fuse carrier with the proper line voltage showing through the small window.
Note that time delay or “slow blow” fuses are required.
Voltage and Fuse information
CAM SETTING
LINE VOLTAGE
FUSE VALUE
110V~
100-120V~
250V~ T 250mA L
220V~
220-240V~
250V~ T 125mA L
aC PoWer CorD
Connect the supplied AC cord to the iec power entry module on the rear panel of the m903. For safety, it is recommended that
the cable be connected to a grounded outlet.
loW VoltaGe DeteCtion
The m903 will automatically detect a low line voltage condition. In the event that line voltage drops below 85 VAC (for 100 -120
vac) or 170 VAC (200 – 220 vac), the m903 will switch into low voltage detection mode. In this mode both headphone and line
outputs are muted, and the 7 segment led will begin to flash. The m903 will automatically store the states of any current output
mutes and return to those states when power is restored.
Power-Up Sequence
The m903’s headphone outputs are protected from any popping when the unit is turned on or off. However, if you are using the
line outputs, observing proper power sequencing is recommended to avoid any potential popping in your speakers. Before pow-
ering up your m903, make sure your monitor speakers or power amps connected to your monitors are turned OFF. Once the m903
and the rest of your audio system are powered up, then turn on the power to your speakers or amplifiers. When powering down,
first power OFF your speaker system and / or power amps and then power down the m903.
Turn power amps on last, turn them off
first!
