© 2002 Wohler Technologies Inc. ALL rights reserved
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AMP2-AM Series User Manual P/N 821540 Rev-A
Please refer to Figure-2a on the following page to familiarize yourself with the front panel features of the AMP2-AM Series unit.
The following sections describe these features and are referenced, by number, to Figure-2a.
Front Panel Features
Section 2: Operation
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3
4
(Continued)
1
6
7
Speaker System
The AMP2-AM series internal
Speaker System
is comprised of two mid-range tweeter speakers (left and right) and one
woofer speaker (center). The two side channel speakers reproduce, in stereo, only the mid and high frequencies. Note that
the woofer speaker (center) is not a dedicated Center nor LFE speaker.
Power Indication LED
This LED glows green to indicate the AMP2-AM Series unit is connected to mains power and an operation voltage is present.
Audio Level Meters (VU or PPM)
Audio levels for the left and right analog sources are visually displayed via these two mechanical level meters. The AMP2-
AMVU model uses meters exhibiting VU ballistic characteristics. The AMP2-AMPPM model uses meters exhibiting PPM
ballistic characteristics. The left and right meters correlate to the left and right analog signals entering the unit..
For information about setting the Threshold Level adjustment and settings for the VU and PPM type of meter see page 17.
Headphone Jack
When headphones are plugged into this jack, the internal speakers will mute. This jack accepts a standard 1/4” phone type
stereo plug.
Volume Control Pot
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 offer instant verification of phase (polarity) conditions in the pair of channels being monitored in the Left/
Right channel speakers. There are three LEDs; the two smaller LEDs labeled "
FAST IN
and
"FAST OUT"
show instantaneous
phase relationships in the signal, while the larger LED, labeled "
AVG
", will indicate the
average
phase condition. The small
"
FAST IN
" LED on the left glows (or blinks) green when signals are
in-phase
. The small "
FAST OUT
" LED on the right
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.
Balance Control Pot
This pans the volume balance between the left and right speakers. If the balance is adjusted hard left or hard right, a slight left/
right channel mix is retained (only in low bass frequencies) so that phase discrepancies can be discerned.
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