Wohler AMP2-SDA/AVU User Manual page 8

AMP2-SDA/AVU and AMP2-SDA/APP User Manual P/N 821576 Rev-A
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.
1
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.
2
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.
3
Power LED
This LED glows GREEN to indicate the unit is connected to mains power and an operation voltage is present.
4
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).
5
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
6
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.
7
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.
8
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.
9
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.
8
Front Panel Features
(Continued)
© 2004 Wohler Technologies Inc. ALL rights reserved
Section 2: Operation