Orban OPTIMOD-FM 8700, Operating Manual

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2-14
INSTALLATION ORBAN MODEL 8700i

The Control Knob is the large blue knob on the front panel. Turning the knob
scrolls through displayed lists (like the Preset screen list) or changes a setting
that is highlighted onscreen (e.g., the setting last selected by the
Locate
joystick).
Pushing the knob in, towards the front panel, displays the pop-up Menu over
the previous screen.

Screen Display supplies control setting information and screen help and displays
the gain reduction and level meters (described directly below).
The 8700i’s screen displays the following meters and indicators:

I
N METERS
show the peak input level applied to the 8700i’s analog or digital
inputs with reference to 0 dB = digital full-scale.

AGC
METERS
show the gain reduction of the slow AGC processing that pre-
cedes the multiband compressor. Full-scale is 25 dB gain reduction.
Because the AGC is a two-band unit with Orban’s patented bass coupling
system, the two meters indicate the gain reduction of the AGC Master
and Bass bands.

G
ATE INDICATORS
show gate activity. They light up when the input audio
falls below the threshold set by the gate threshold controls. (There are two
gating circuits—one for the AGC and one for the multiband limiter—each
with its own Gate Thresh control.) When gating occurs, the AGC and com-
pressor’s recovery times are slowed drastically to prevent noise rush-up dur-
ing low-level passages.

M
ULTIBAND GAIN REDUCTION METERS
show the gain reduction in the multiband
compressor. Full-scale is 25 dB gain reduction. The MB GR M
ETER
switch (in
I
NPUT
/O
UTPUT
> U
TILITIES
) determines what signals the 2-Band and 5-Band
Compressor gain reduction meters indicate. The switch can be set to FM , HD ,
or
S
PLIT
. In
S
PLIT
mode, the 8700i’s front panel display shows the gain reduc-
tion of the FM analog multiband compressors on the left side of the split
meters and the gain reduction of the digital radio compressors on the right.
If the left and right channel gain reductions are not identical in a given
band, its meter displays the larger of the left or right channel gain reduc-
tions.

2B HF meters display the gain reductions in dB of the independent left and
right channel high frequency limiters in the 8700i’s Two-Band structure.
These meters appear only when the 8700i is in Two-Band mode.

O
UT METERS
display 8700i’s instantaneous peak output level.

C
OMP METER
displays the stereo encoder’s output level before the
C
OMP
1
or
C
OMP
2
attenuators, in percent scale over a 125 to 0 range.

HD
METERS
display the gain reduction of the left and right look-ahead lim-
iters that feed the HD outputs.