Manual-1
DA 26S
DISTRIBUTION AMPLIFIER
Operators Manual
WEAR PARTS:
This product contains no wear parts.
Quick Start
Are you in a hurry? For optimum system performance, we recommend reading the detailed
Setup & Operation
below and on page
Manual-4. For those who can’t wait, at least be aware of these points:
• There are two inputs:
PRIORITY
and
LINE
. The
PRIORITY Input
accepts MIC or LINE level.
• The
PRIORITY Input
sums with an output when assigned by the
PRIORITY ASSIGN Port
, and
PRIORITY DETECT
is ac-
tive.
• The level of the
PRIORITY Input
is unaffected by the
AGC
,
Output Level
controls or
Remote Level
controls.
• The
AGC
only operates when the signal is within 26 dB of the
Target Level
. If the Line Input level is out of
AGC
range, the
0 dB
indicator on the
AGC GAIN
meter is off.
• With the
RATIO
set to
∞:1
, the
AGC GAIN
meter should indicate about
0 dB
for nominal Line Input levels.
• The
AGC SLOW / FAST
switch only affects the gain reduction time constant. The gain increase time constant is fixed.
• Only the
LINE Input
is processed by the
AGC
,
CROSSOVER
,
Output Level
and
Remote level
controls.
• The three
Crossover Outputs
(full-range, high-pass and low-pass) may be selected by any of the six Outputs.
• Set the initial Output levels using the
Output Level
controls on the front panel.
•
Remote Level
controls allow end user adjustment of Output level.
• Any combination of
Remote Ports
may be controlled by a single Remote device.
•
Remote Level
controls provide automatic loudness compensation for low-pass Outputs. Loudness compensation is not provided for
full range Outputs.
• The optional
VR 1 Remote Level control
provides audio taper control over a range of 0 dB to –80 dB.
Setup & Operation
The outline below is detailed in the following procedure.
1. Set Line Input level
2. Set AGC (Automatic Gain Control) Target Level and Ratio
3. Set Crossover frequency
4. Select Source for each Output (Full-range, High-pass or Low-pass)
5. Set Output Level controls
6. Connect Output Remote Level controls
7. Connect the Priority Input for the intended source
8. Set the Priority Input automatic Detect threshold
9. Set Ducking depth for the application
10. Priority Assign selection
1. Connect a balanced line level source to the Line Input. The
Line Input accepts an unbalanced Input connected to (+) and
(GND). We do not recommend unbalanced operation unless
the distance to the source is less than 3 feet [one meter].
2. The Line Input signal is processed by the AGC circuit. The
AGC GAIN meter 0 dB indicator lights when the Line Input
signal is within 26 dB of the set TARGET LEVEL. For Line
Input levels more than 26 dB
below
the Target Level, the 0 dB
indicator is
off
and AGC returns to unity. The AGC GAIN
indicates the amount of attenuation used to make the Line
Input level equal the set TARGET LEVEL. For best results,
the AGC GAIN meter should indicate about 0 dB for nomi
-
nal Line Input signals.
The best resolution for this adjustment is
achieved with the AGC RATIO set to
∞:1.
The TARGET LEVEL is set in one of two ways:
a) If you have a source output level control, set the TARGET
LEVEL to the desired setting and adjust the Line Input
level so that the AGC GAIN meter indicates 0 dB for
nominal signal levels.
b) If a source output level control is not available, adjust the
TARGET LEVEL so the AGC GAIN meter indicates 0 dB
for nominal Line Input levels. The difference between the
resulting AGC Target Level and the desired Target Level is
compensated with the OUTPUT trims. With Input level
and TARGET LEVEL correctly set, adjust the AGC RA
-
TIO to the desired value. We recommended values between
2:1 and ∞:1 as marked by the gray band. The soft-knee-
response of the AGC results in a natural sounding response
with AGC Ratios as high as ∞:1.
3. The CROSSOVER splits the Line Input signal into three
separate Outputs: Full-Range, High-pass and Low-pass, each
selectable for each of the six Outputs. Select the desired FRE
-
QUENCY (80, 110,150 or 200 Hz).
continued on page Manual-4...
dBu
dB
+4
ON
MIN MAX
-12
-80
0
+12
1:1
:1
dBu
-12
+12
-12
+12
-12
+12
-12
+12
-12
+12
-12
+12
-12 -6 -3
0
3
6 12
DA 26S
DISTRIBUTION
PROCESSOR
DETECT
PRIORITY
GAIN
DUCKER
AGC
1
CROSSOVER
OUTPUTS
POWER
OL
SLOW
ACTIVE
LEVEL
RATIO
FAST
GAIN
TARGET
HIGH
FULL
LOW
3
HIGH
FULL
LOW
2
HIGH
FULL
LOW
4
HIGH
FULL
LOW
5
HIGH
FULL
LOW
6
HIGH
FULL
LOW
FREQUENCY
150
110
80
200
