Orban OPTIMOD 8400 Operating Manual page 67

OPTIMOD-FM
Control at the studio (such as an Orban 8200ST OPTIMOD-Studio or 464A
Co-Operator), the AGC in the 8400 should be defeated. This is so that the two
AGCs do not "fight" each other, and so they do not simultaneously increase
gain resulting in increased noise.
If you are using an Orban 4000 Transmission Limiter, set field to
the AGC function in the 8400 continues to work). The Orban 4000 is a trans-
mission system overload protection device; it is normally operated below
threshold. It is not designed to perform an AGC or gain-riding function, and it
cannot substitute for the AGC function in the 8400.
7. Set Input Levels.
A) Adjust Input Reference Level.
Feed normal Program material to the 8400.
a)
Play program material from your studio, peaking at normal program levels
(typically 0VU if your console uses VU meters).
to the Reference Levels screen (System Setup: Quick Setup 5).
b) Locate
The Reference Level screen allows you to match the 8400 to the normal op-
erating level to be expected at the 8400, so the 8400's AGC can operate in
the range for which it was designed. There are separate settings for the ana-
log and digital inputs. If you provide both analog and digital inputs to the
8400, optimum adjustment is achieved when the desired amount of process-
ing is indicated for either analog or digital inputs. This will allow you to
switch between analog and digital inputs without sudden level changes.
c) Set the input to
[Skip this step if you are not using the analog input.]
d) Adjust the
gain reduction.
[−9 dBu to +13 dBu (VU), or –1 to +21 dBu (PPM)] in 0.5 dB steps
The
Analog Reference Level VU
offset of 8 dB. This compensates for the typical indications with program
material of a VU meter versus the higher indications on a PPM.
If you know the reference VU or PPM level that will be presented to the
8400, set the
the steps shown directly below.
If the
(higher on the meter), re-adjust the
If the
meter), re-adjust the
This control has no effect on the AES/EBU digital input.
Set the input to
e)
[Skip this step if you are not using the digital input.]
Analog and adjust
Analog Reference Level
Analog Reference Level
gain reduction meter averages less than 10 dB gain reduction
AGC
gain reduction meter averages more gain reduction (lower on the
AGC
Analog Reference Level
and adjust
Digital
Analog Reference Level
so that the meter reads an average of 10 dB
and settings track each other with an
PPM
to this level, but please verify it with
Analog Reference Level
to a higher level.
Digital Reference Level
INSTALLATION
(so that
No
.
to a lower level.
.
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