AMP1-DA
User Manual P/N
821530
Rev-
C
© 2006 Wohler Technologies Inc. ALL rights reserved
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Please refer to
Figure-2a
on the following page to familiarize yourself with the front panel features of the
AMP1-DA
unit. The following
sections describe these functions and are referenced, by number, to
Figure-2a
.
Section 2: Operation
Front Panel Features
Speakers
The
AMP1-DA
internal speaker system is comprised of two mid-range tweeter speakers (left and right) and two woofer speakers
(left and right). The two mid-range speakers reproduce, in stereo, only the mid and high frequencies, while the two woofer speakers
monorally reproduce the low frequencies. See page
14
for more information about the speaker configuration of the
AMP1 Series
.
Volume Control
This controls the loudness of the audio reproduced by the internal speakers or connected headphone. Clock-wise rotation of this
control increases the loudness of the monitored audio.
Headphone Jack
Select the headphone audio sources as you would for the internal speakers. When you plug in headphones, the internal speakers will
mute. This jack accepts a standard "mini" stereo (ring/tip/sleeve) plug.
Power Indication LED
This LED glows green to indicate the unit is connected to operational mains power.
Phase Indication LEDs
These three LEDs offer instant visual verification of phase (polarity) conditions in the pair of channels selected for monitoring in the
Left/Right channel speakers. The two
smaller
LEDs, labeled
Φ
Φ
Φ
Φ
Φ
+
and
Φ
Φ
Φ
Φ
Φ
-
(above and below), show
instantaneous
phase relationships
in the signal, while the
larger
center LED, labeled
AVG
, indicates the
average
phase condition.
The small top
Φ
Φ
Φ
Φ
Φ
+
LED glows (or blinks) GREEN when signals are
in-phase
. The small bottom
Φ
Φ
Φ
Φ
Φ
-
LED glows (or blinks) AMBER
for
out-of-phase
signals. The larger
AVG
LED indicates the
average
phase condition by glowing GREEN for
in-phase
conditions,
or RED for
out-of-phase
conditions.
In general, it is sufficient to regard the
AVG
LED (average phase condition) as adequate for proper phase monitoring. While it is
normal for stereo signals to contain some intermittant instantaneous out-of-phase and in-phase conditions (small LEDs), a steady
red glow of the larger LED almost always indicates an out-of-phase alarm condition.
Audio Level Meters
Audio levels for the selected input sources are displayed via these two 26-segment tri-color (GREEN, AMBER, RED) LED
bargraph display level meters.
These two bargraph displays feature an
Auto-Calibration
feature and are user adjustable for
Display Mode
and
Reference Level
via a rear panel DIP module (
Item F
, page
12
).
Peak Hold
,
PPM Ballistics
, and
Alternative Scales
can be set via an
internal
DIP module. See pages
18
and
19
for more information regarding these DIP switch module locations and settings.
AES/EBU Signal Status Indication LED
This LED indicates the
status
of the currently selected
AES
digital signal (
AES1
or
AES2
) regardless of any other monitor
selection settings.
This LED glows GREEN as long as a valid
AES
digital datastream is being received. It will glow RED to indicate errors in the
reception of the
AES
signal. There are two DIP switch selectable modes of fault detection that will create a RED LED error
indication. Please see
Item B
, page
10
for more information about this setting.
An additional feature of the
AES
signal error detection is the ability to mute the audio when errors are detected in the
AES
signal. To
enable this feature, a jumper is placed at
H12
of the
919117
PCB. See page
21
for location of
H12
on the
919117
PCB.
Digital Source Select Switch
This switch selects between the two
AES/EBU IN
(
IN1
or
IN2
)
source inputs (
Item C
, page
10
). Note that for the selected
AES
source to be monitored, the
Analog/Digital Source Select Switch
(
Item 9
) must be set to
DIGITAL
.
Analog/Digital Source Select Switch
When this toggle switch is set to
ANALOG
, the unit will monitor the
analog
input signals from the
ANALOG IN
XLR connectors
on the rear panel (
Item G
, page
14
). When this toggle switch is set to
DIGITAL
, the unit will monitor the selected
AES/EBU IN
input (
IN1
or
IN2
) on the rear panel (
Item C
, page
10
).
Balance Control
This pans the volume balance between the left and right speakers. See page
14
for more information about the balance control
characteristrics of the
AMP1 Series
.
Bargraph Brightness Adjust
This control is recessed into the front panel and can be accessed using a small flathead screwdriver. Turning the trim pot clockwise
will simultaneously increase the relative brightness of the LED segments in both bargraphs.