© 2004 Wohler Technologies Inc. ALL rights reserved
8
AMP2-SDA/AVU
and
AMP2-SDA/APP
User Manual P/N
821576
Rev-
A
4
1
2
3
6
7
8
5
9
Please refer to
Figure-2a
on the facing page to familiarize yourself with the front panel features of the
AMP2-SDA/AVU
and
AMP2-SDA/APP
units. The following sections describe these features and are referenced, by number, to
Figure-2a
.
Front Panel Features
Section 2:
Operation
(Continued)
Speakers
The monitor features two mid-range speakers (left and right) and
one
woofer speaker. Two amplifier/driver combinations
handle midrange and high frequency information in the left and right (stereo) speaker channels, while the third channel
reproduces and sums the left and right channel information below the 500 Hz crossover point in the woofer (bass) speaker(s).
Note that the woofer channel is NOT a dedicated
LFE
(subwoofer) or
Center
channel. See page
16
for more information
concerning the
AMP2 Series
audio amplifier/speaker configuration.
Audio Level Meters - Mechanical
Audio levels for the left and right sources selected for monitoring are respectively displayed in the left and right mechanical
level meters. The
AMP2-SDA/AVU
model uses meters exhibiting
VU
ballistic characteristics. The
AMP2-SDA/APP
model uses meters exhibiting
PPM
ballistic characteristics. See page
21
for specifications and settings for the
VU
and
PPM
type of mechanical meter.
Power LED
This LED glows GREEN to indicate the unit is connected to mains power and an operation voltage is present.
Analog/Digital Source Select Switch
This two position toggle switch allows the operator to choose between two primary input sources;
ANALOG
or
DIGITAL
.
When this toggle switch is set to
ANALOG
, the unit will monitor the signals as input on the rear panel
ANALOG IN
XLR
connectors (
Item H
, page
14
). When this toggle switch is set to
DIGITAL
, the unit will monitor the digital source (
AES
or
SDI
) as selected by the
AES/SDI Source Select Switch
(
Item 6
).
SDI Subgroup Select Switch (1 or 2)
This 2-position toggle switch allows the operator to choose whether the unit will monitor
Subgroup 1
or
Subgroup 2
of
the
SDI
data stream when the
AES/SDI Source Select Switch
(
Item 6
) is set to
SDI
.
Subgroup selections
1
and
2
are derived from
Group I.D. #1
as follows:
•
Subgroup 1
= Channels
1
and
2
•
Subgroup 2
= Channels
3
and
4
AES/SDI Source Select Switch
This two position toggle switch allows the operator to choose between the two types of digital input sources provided for
on the rear panel;
AES
or
SDI
. It should be noted that in order for the unit to actually monitor the selected digital source,
the
Analog/Digital Source Select Switch
(
Item 4
) must be set to
DIGITAL
.
Headphone Jack
This jack accepts a standard 1/4” phone type stereo plug. Select the headphone audio sources as you would for the internal
speakers. When you plug in headphones, the speakers will mute.
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.
Phase Indication LEDs
These three LEDs indicate the instantaneous and average phase (polarity) conditions between the two signals in the channel
pair (or downmix) assigned to the left and right speaker channels. The two smaller LEDs labeled
FAST
show
instantaneous
phase relationships in the signal. The larger LED labeled
AVG
will indicate the
average
phase condition. Indication is as
follows:
•
The
left
FAST
LED glows (or blinks) GREEN for
in-phase
signals.
•
The
right
FAST
LED glows (or blinks) AMBER for
out-of-phase
signals.
•
The large
AVG
LED indicates the
average
phase condition by glowing GREEN for
in-phase
signals, or RED for
out-of-phase
signals.
In general, observing the
AVG
LED alone is sufficient for proper phase monitoring. While it is normal for stereo signals to
contain some intermittant instantaneous
out-of-phase
and
in-phase
conditions (
FAST
LEDs), a steady RED glow of the
AVG
LED indicates an
out-of-phase
alarm condition.
