User`s manual

Page 6
the VOLUME knob always controls only the headphone level; the rear-panel
output level is not adjustable.
3.1.3 Input Level Controls
The center section of the front panel contains INPUT LEVELS controls for the
input signals. The four LEDs above each knob provide level bargraphs for each
of the input signals. The red LED in each bargraph indicates that the audio is
overdriving. In general, it is a good idea to make your input signals fairly loud but
without overdriving. Ideally, your input signals will light the yellow “-6dB” LED at
their loudest parts, but never the red “OL” LED.
Also, note that each of the four inputs has an associated ACTIVE LED, in order
to indicate whether that particular input is in use in the selected filtering mode,
and what it is being used for. GREEN illumination indicates the input is being
used as a primary input for the multi-channel adaptive filter, while RED
illumination indicates the input is being used as a reference. When the LED is not
illuminated, the input is not in use in the selected mode.
For the ANALOG INPUTS, the level adjustment is applied to the analog signal
using the analog amplifier, with a range of +/- 30 dB. For the digital inputs, the
level adjustment is applied digitally, with exactly the same adjustment range.
3.1.4 Filter Controls
The right-hand section of the front panel contains FILTER CONTROLS used to
change the behavior of the filtering applied by the MicroDAC 5. The individual
controls are described in more detail below.
3.1.4.1 Channel Selection Controls
There are two controls on the front panel that can be used to define the input
audio channels. The MONO/STEREO select is used to specify whether there
are one or two primary channels. The nCH selection is used to specify the
number of reference signals, and which inputs those references are found on.
Choose 1CH for no reference cancellation, 2CH for a single reference, 3CH for
two references, and 4CH for three references (available only when the primary is
MONO). Together, these two controls allow a total of 9 channel modes, shown in
the table below: