© 2004 Wohler Technologies Inc. ALL rights reserved
20
AMP2A-VTR
and
AMP2A-VTR2
User Manual P/N
821580
REV-
B
Since it is sometimes helpful to observe phase relationships between two signals being monitored, a
Phase Correlation
feature can be implemented within the lower section of an existing bargraph pair in the 53-segment LED bargraph level
meters used in the
AMP2
units. This feature may be turned ON and OFF by setting the
Level Meter Internal 10-Position
DIP Swich
module (page
18
). Below is an illustration of the level meter bargraphs with the
Phase Correlation
label applied.
When the audio level in BOTH channels is high enough, the
Phase Correlation
display occupies the lower few segments of
both bargraphs of a stereo pair. Behavior of the
Phase Correlation
indication is as follows:
Positive
correlation = ascending
AMBER
bar in the
right
bargraph
Negative
correlation = ascending
RED
bar in the
left
bargraph
The bottom nine (9) segments are used by the 53-segment LED bargraph display for
Phase Correlation
indication. One
additional segment above the active correlation region is always OFF, to serve as a marker. The
Phase Correlation
display
is visible ONLY so long as the VU audio level is above this blank segment (
tenth
from the bottom).
Level Meter Phase Correlation Feature
15
50
30
40
35
26
22
18
4
6
10
12
2
2
0
15
8
6
12
-1
.5
0
correlation
+1
.5
0
Section 3:
Technical Information
Level Meter Alternative Scales
The standard scale used on the
AMP2A-VTR
and
AMP2A-VTR2
level meters (53-segment) is the
Extended VU
scale (see diagram
below). However, if alternative scale characteristics are selected for the level meters using the
Level Meter Internal 10-Position DIP
Switch
(page
23
), it is recommended that a label with the appropriate scale be applied to the front panel LED bargraph level meters. See the
diagram below for scale comparison. Scale selection includes the
Extended VU
(standard Analog),
VU
,
BBC
,
NORDIC
,
DIN
, and
Custom
(not shown) scales. Contact
Wohler Technologies
for information about alternative scale labels.
-20
-15
-10
-5
-7
-1
-2
-3
0
+1
+3
+2
-33
-42
-36
-24
-30
-27
-21
-18
-15
+6
-3
-12
-9
-6
T
+3
+9
+12
-40
-50
-20
-30
-10
-5
0
+5
NORDIC
Scale
DIN
Scale
VU
Scale
3
4
1
2
7
5
6
BBC
Scale
50
12
12
26
30
35
40
18
15
22
0
10
6
2
6
8
2
4
15
56
66
4
25
31
28
34
46
51
38
42
10
7
16
22
20
18
13
2
0
AES
(
Digital
)
Scale
(standard)
Extended VU
(
Analog
)
Scale
(standard)
