© 2005 Wohler Technologies Inc. ALL rights reserved
8
VM SDI Digital Series
User Manual P/N
821625
Rev-
A
1
2
3
4
5
6
7
8
9
10
Please refer to
Figure-2a
on the facing page to familiarize yourself with the front panel features of the
VM SDI Digital Series
units. The following sections describe these features and are referenced, by number, to
Figure-2a
. Note that even though only the
VMMDA-1
front panel is shown, features and operation are identicle for the
VMSDA-1
.
Front Panel Features
Section 2:
Operation
Speakers (Left, Right, and Woofer)
The
VM SDI Digital Series
audio monitors feature two mid-range speakers (left and right) and one woofer speaker. See
page
12
for a description and diagram of the audio amplifier and speaker configuration.
Volume Control
This adjusts the loudness of the audio reproduced by the internal speaker channels or connected headphone.
Audio Level Meter Bargraphs (Left and Right)
Audio levels for the selected source channels (left and right) are displayed via these two 10-segment LED bargraph audio
level meters. Meters have a dynamic range of 23 dB and levels are displayed using both VU and PPM dynamics.
SDI Lock Status LED
This LED indicates the lock status of the
SDI
source signal. It glows GREEN to indicate a
locked
SDI
signal and is unlit to
indicate an
unlocked
SDI
signal (or that no
SDI
source is connected). This LED indicates
SDI
lock status continuosly
regardless of any other selection settings.
SDI Group Channel Select Switch
This 8-position rotary switch selects one of the eight channel pairs (from
SDI Groups 1-4
) that will be monitored from the
connected
SDI
source. Note that in order to audibly monitor the selected
SDI
channel pair, the
Source Select Switch
(
Item 10
) must be set to
SDI
.
Headphone Jack
This jack accepts the 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.
Power Indication LED
This LED glows GREEN to indicate the unit is connected to mains power and an operation voltage is present.
Balance Control
This control adjusts the volume balance between the left and right speaker channels. See page
12
for a description of the
balance control characteristics within the amplifier and speaker configuration.
Phase Indication LEDs
These three LEDs indicate the instantaneous and average phase (polarity) conditions between the two signals in the channel
pair 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.
Source Select Switch
This 3-position toggle switch selects the source to be monitored through the unit (
SDI
,
AES
, or
analog
).
