Orban Optimod-PC 1101, Operating Manual

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2-44
INSTALLATION ORBAN MODEL 1101
band structure. When the loudness controller is on, both structures have
comparable loudness control.
If you chose an appropriate D
IALNORM
value for your transmission, the
1101’s limiting meters should rarely indicate any gain reduction.
The Direct Mixer
There are two Direct Mixers, one for each sound card. The Direct Mixers (see Figure
2-6 on page 2-32) determine the gain applied to input signals before these signals
are sent directly (without OPTIMOD-PC processing) to the output routing switcher. If
the output attenuator in the routing switcher is set to “0dB” and the analog input
and output reference levels are set identically (to +4dBu or –10dBv), then the Direct
Mixer faders will indicate the input/output gain directly in dB.
The default settings of “0dB” provide unity gain in and out of the OPTIMOD-PC card
for both the analog and the digital inputs. If you want to change a reference level
between a source and destination (for example, from –16dBfs to –18dBfs), you can
do so by adjusting the fader corresponding to the source (in our example, by setting
it to –2dB).
Note that you are limited by input headroom: if you set the D
IGITAL
1 fader to –2dB,
OPTIMOD-PC’s digital output level cannot exceed –2dBfs because this level corre-
sponds to 0dBfs at OPTIMOD-PC’s digital 1 input.
If you are using a digital input and an analog output, note that OPTIMOD-PC’s in-
ternal gain for both input and output is such that 0dBfs = +24dBu. OPTIMOD-PC’s
output line amplifiers can drive +24dBu into a
balanced load. However, the maxi-
mum analog output level they can drive into an unbalanced load is +18dBu. There-
fore, to match analog and digital clipping levels when driving an unbalanced load
with
A
NALOG
R
EFERENCE
L
EVEL
= +4dBu, set the A
NALOG
O
UTPUT
fader to –6dB.
The A
NALOG
O
UTPUT
fader is located in the O
UTPUT
L
EVELS
page.
If you are mixing more than one active input, be careful not to exceed the head-
room of OPTIMOD-PC’s mix bus, whose peak level is indicated by the
M
IXER
O
UTPUT
meters on both the
P
ROCESSOR MIXER
and
D
IRECT
M
IXER
pages. To prevent clipping,
do not permit the
“0” S
EGMENT
O
F
this meter to light.
Interfacing OPTIMOD-PC with WAVE Applications
Turning Off Windows Sounds
If OPTIMOD-PC is the Windows Preferred or Default Device, to prevent Windows’
OS-generated and application-generated sounds from going “on the air” or over
your stream you must turn them off.