Connections and Controls
REAR PANEL
USB Connector #1 - Data / Signal / Bus Power Input
Asynchronous USB 2 interface for bit perfect, zero interface induced jitter DAC operation.
Accommodates 44.1kHz to 384kHz PCM and 64X - 128X DSD. Driverless operation with MAC OS.
USB Class 2 operation with Windows up to 384kHz with free driver download from Grace Design.
When nothing is connected to the USB connector #2, the m9XX is bus powered through this
interface and operates in Low Power mode.
USB Connector #2 - High Power Input
Use this power connection to operate the m9XX in High Power mode. This connector carries only
DC power and no USB data. Once the included low noise 2A USB power supply is plugged into this
input, the m9XX will enter High Power mode (indicated by “HP” on the 7-segment display).
TOSLINK Optical Input
Accepts up to 96kHz, 24 bit PCM digital audio signal. Automatic de-emphasis equalization. The
m9XX setup menu contains an input select option that toggles between the USB input or the
TOSLINK input. See the Setup Menu section in this manual for more setup information.
Line Outputs
Unbalanced, level controlled line outputs via a pair of gold plated RCA phono jacks. These outputs
are designed to connect to a power amp, powered speakers, preamps, or headphone amps. When
headphones are connected to the right hand jack, the line output signal is muted.
FRONT PANEL
Headphone Outputs
Parallel headphone outputs wired to high quality TRS jacks. When headphones are connected to
the right hand jack, the line output signal is muted.
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