MOTU 828es, Руководство пользователя

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H A R D W A R E I N S T A L L A T I O N
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AUDIO CONNECTIONS
Here are a few things to keep in mind as you are
making audio connections to your 828es interface.
Mic/line/instrument inputs with preamps
Connect a microphone, guitar or line-level analog
input to the front panel XLR/quarter-inch combo
jack with either a standard mic cable or a balanced
cable with a quarter-inch plug.
☛
Do not connect a +4 (line level) XLR cable to
the front-panel inputs (because of the preamps).
Use a quarter-inch input instead.
Phantom power
If you are connecting a condenser microphone or
another device that requires phantom power,
engage the corresponding front-panel phantom
power switch.
Preamp gain
The 828es preamps provides 63 dB of gain. Use the
front panel detented trim knobs to adjust gain as
needed for each input. The LCD provides visual
feedback as you turn the trim knob. Preamp gain
is digitally controlled, so you can make fine-tuned
adjustments in 1dB increments. You can also
adjust preamp gain in the web app. See “Device
tab” on page 12.
-20 dB pad
Each mic input (XLR jack) is equipped with a
-20 dB pad switch, to accommodate input signals
that could overdrive the input.
Combo jack summary
Use these guidelines for 48V phantom power, pad
and trim settings on the two combo input jacks:
TRS quarter-inch analog inputs and outputs
Quarter-inch analog inputs and outputs are
balanced (TRS) connectors that can also accept an
unbalanced plug. The outputs are DC-coupled, so
they can be used for CV control output.
☛
Quarter-inch analog outputs are not
cross-coupled. Therefore, when connecting them
to an unbalanced input, use a TRS plug with the
ring disconnected. Not floating the negative
terminal will short it to the sleeve ground and
cause distortion.
Main outs
Like all I/O on the 828es, the XLR main outputs
operate as an independent pair (they don’t share
signal with any other output pair). In a standard
studio configuration, the main outs are intended
for a pair of primary studio monitors, but they can
be used as regular outputs for any purpose. With
adjustable converter trim, they support a wide
range of industry-standard reference levels. Main
out volume is controlled by pressing the
A button
on the front panel (Figure 5-14) and then
adjusting volume with the MONITOR knob.
Figure 5-14: 828es front panel
Input
48V Pad Trim
Condenser mic On As needed As needed
Dynamic mic Off As needed As needed
Guitar Off n/a As needed
-10 dB Line level via TRS Off n/a As needed
-10 dB Line level via XLR Off -20 dB +12dB
+4 dB line level (TRS only) Off -20 dB Zero