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INSTALLATION ORBAN Model 8400
D) Calibrate with an Orban 464A Co-Operator:
[Skip this step if you are calibrating in another manner.]
The 464A does not have a built-in 100% tone. The easiest way to set the
8400 input peak clipping level is to temporarily re-adjust the 464A to pro-
duce clipped waveforms on program material to give a clear indication of
peak clipping level.
a)
Record the normal operating settings of the 464A.
b) Set both channels of the 464A controls as follows:
METER CAL 0
HF LIMIT PRE-EMPHASIS set to pre-emphasis of your STL;
if no pre-emphasis, set to 25μs
OUTPUT ATTEN 0
INPUT ATTEN 10
GATE THRESH 0
RELEASE TIME 0
REL SHAPE SOFT
LEVEL OFF
COMPR OFF
HF LIMIT OPERATE
SYSTEM OPERATE
POWER ON
MODE DUAL
c)
Play program material from your studio.
d) Adjust the 464A’s METER CAL controls so that the 0 dB segment on the 464A’s
PEAK OUTPUT LEVEL meter just illuminates on program peaks.
e) Adjust the 464A’s OUTPUT ATTEN controls to drive the STL to 100%
modulation.
f) Adjust the 8400’s Clip Level so that the program peaks indicate approximately
–2 dB on the meter on the screen.
g) Return the 464A to the normal settings.
4. Adjust Reference Level.
[−4 dBu to +13 dBu (VU), or +4 to +21 dBu (PPM)] in 0.5 dB steps
The Reference Level VU and PPM (Peak) settings track each other with an
offset of 8 dB. This compensates for the typical indications with program
material of a VU meter versus the higher indications on a PPM.
This step sets the center of the 8400’s gain reduction range to the level to
which your studio operators peak their program material on the studio me-
ters. This ensures that the 8400’s processing presets will operate in their pre-
ferred range.
You may adjust this level with a standard reference/line-up level tone from
your studio or with program material.
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