power will be drawn from the computer port. If running in High Power mode and the power supply
is disconnected, the m9XX will reboot.
Below is a summary of all of the powering and signal input configurations:
1.
Low Power, USB input:
One USB cable from the computer to the m9XX #1 USB input.
m9XX receives power and audio from the computer.
2.
High Power, USB input:
One USB cable from the computer to the m9XX #1 USB input and
one USB cable from the external 2A DC power supply to the m9XX #2 high power DC input
connector. The m9XX receives audio from the computer and receives power from the
external DC supply.
3.
Low Power, TOSLINK input:
One USB cable from a standard USB power source (computer
or 0.5A USB power supply) connected to the m9XX #1 USB input. TOSLINK optical cable
connected to the TOSLINK input. (This would be an unusual setup where you don't have
access to a high power DC power supply.)
4.
High Power, TOSLINK input:
One USB cable from the 2A DC power supply to the m9XX #2
high power DC input connector. TOSLINK optical cable connected to the TOSLINK input.
m9XX receives audio from TOSLINK and power from the external DC supply.
5.
Self Powered Mode:
This mode is for connecting your mobile device (iOS, android) to the
m9XX. Mobile devices generally cannot provide any power. In this mode the m9XX will
report that it is self powered. To enter self powered mode, first connect the USB cable from
the external 2A DC power supply to the m9XX #2 high power DC input connector, then
connect your device to the m9XX #1 USB input. For iOS, you will need the 'Apple Lightning
to USB Camera Adapter', for supported Android devices you will need an 'On The Go' USB
cable.
Connecting Headphones
There are 2 ¼” headphone output jacks on the front, which are wired in parallel. The second jack on
the right is a switched type. If you have the line outputs connected to a power amp or powered
monitors, connecting headphones to this jack will automatically mute the line outputs, allowing
you to effectively ‘toggle’ between the headphone and speaker outputs.
IMPORTANT NOTE:
The m9XX has very low output impedance, measuring around 0.08 Ohms.
Ohm's law states that as the load impedance approaches 0 Ohms, even a small voltage will result in
high current flow. When a headphone plug is inserted in to the headphone jack of any headphone
amplifier, there is a brief moment when the output of the amplifier gets shorted to ground. If there
is music playing when this happens, there will be high current flow which will likely cause the
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