Orban OPTIMOD-FM 8700, Operating Manual

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OPTIMOD-FM DIGITAL TECHNICAL DATA
6-3
Signal-to-Noise: > = 90 dB unweighted (Bypass mode, de-emphasized, 20 Hz - 15 kHz
bandwidth, referenced to 100% modulation).
Crosstalk: <=
–70 dB, 20 Hz - 15 kHz.
Distortion: <= 0.01% THD (Bypass mode, de-emphasized) 20 Hz - 15 kHz bandwidth.
Connectors: Two XLR-type, male, EMI-suppressed. Pin 1 chassis ground, Pins 2 (+) and 3
electronically balanced, floating and symmetrical.
D/A Conversion: 24 bit 128x oversampled.
Filtering: RFI filtered.
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 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, and 96 kHz automatically selected.
Connector: XLR-type, female, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 trans-
former balanced and floating, 110

impedance.
Input Reference Level : Variable within the range of
–30 dBFS to –10 dBFS.
J.17 De-emphasis: Software-selectable.
Filtering: RFI filtered.
Hardwire Bypass: Removing power from the Optimod will connect the Digital Audio
Input to Digital Output #1 via a relay.
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 preemphasis (50
µ
s or 75
µ
s). 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 preemphasis 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, 110

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 preemphasis 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 pro-
cessing channel diversity delay. Once set, this delay is constant regardless of pro-
cessing preset in use.