Orban OPTIMOD-FM 8500S Operating Manual page 285

OPTIMOD-FM DIGITAL
Digital Audio Input
Configuration: Stereo per AES3 standard, 24 bit resolution, software selection of stereo,
mono from left, mono from right or mono from sum.
Sampling Rate: 32, 44.1, 48, 88.2, or 96 kHz, automatically selected.
Connector: XLR-type, female, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 trans-
former balanced and floating, 110Ω impedance.
Input Reference Level: Variable within the range of –30 dBFS to –10 dBFS.
J.17 De-emphasis: Software-selectable.
Filtering: RFI filtered.
Digital Audio Outputs
Configuration: Two outputs, each stereo per the AES3 standard. The outputs can be inde-
pendently set to emit the analog FM processed signal, the digital radio processed signal,
or the low-delay monitor signal. The FM processed signal can be configured in software
as flat or pre-emphasized to the chosen processing pre-emphasis (50µs or 75µs). The
digital radio processing chain receives the output of the multiband limiter and processes
it through a look-ahead peak limiter that operates in parallel with the main FM peak limit-
ing system. The DR and FM signals are always simultaneously available. Each output
can apply J.17 pre-emphasis if desired.
Sample Rate: Internal free running at 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, or 96 kHz, se-
lected in software. (Use 44.1 kHz or higher for best peak control.) Can also be synced to
the AES3 SYNC input or the AES3 digital input at 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz,
and 96 kHz, as configured in software.
Word Length: Software selected for 24, 20, 18, 16 or 14-bit resolution. First-order highpass
noise-shaped dither can be optionally added, dither level automatically adjusted appro-
priately for the word length.
Connector: XLR-type, male, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 trans-
former balanced and floating, 110Ω impedance.
Output Level (100% peak modulation): –20.0 to 0.0 dBFS software controlled.
Filtering: RFI filtered.
Frequency Response (Digital Audio Output (from Digital Radio Processing Chain)):
For output sample rates of 44.1 kHz and above, the frequency response from input to
DR-configured output is ±0.10 dB, 2.0 Hz - 20 kHz; flat or with J.17 pre-emphasis ap-
plied. The user may specify lowpass filtering to constrain the bandwidth to 15, 16, 17,
18, or 19 kHz.
Relative Time Delay between FM and HD Outputs: Depends on setting of analog proc-
essing channel diversity delay. Once set, this delay is constant regardless of processing
preset in use.
Wordclock/10 MHz Sync Reference
Configuration: Accepts 1x wordclock or 10 MHz reference signals, automatically selected.
The DSP master clock can be phase-locked to these signals, which in turn phase-locks
the 19 kHz pilot tone frequency, facilitating singe-frequency network operation. The digi-
tal output sample frequency can also be locked to these signals.
Level: Unit will lock to 1x wordclock and 10 MHz squarewaves and sinewaves having a
peak value of 0.5 V to 5.0 V.
Connector: BNC female, grounded to chassis, non-terminating to allow reference signals to
be looped through via an external BNC "tee" connector (not supplied).
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TECHNICAL DATA