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Optimod-FM 8500

Specifications

It is impossible to characterize the listening quality of even the simplest limiter or compressor based on specifications, because such specifications cannot adequately describe the crucial dynamic processes that occur under program conditions. Therefore, the only way to evaluate the sound of an audio processor meaningfully is by subjective listening tests.

Certain specifications are presented here to assure the engineer that they are reasonable, to help plan the installation, and make certain comparisons with other processing equipment.

Performance

Specifications apply for measurements from analog left/right input to stereo composite output and to FM analog left/right output.


Frequency Response (Bypass Mode; Analog Processing Chain): Follows standard 50µs or 75µs pre-emphasis curve ±0.10 dB, 2.0 Hz - 15 kHz. Analog left/right output and Digital output can be user configured for flat or pre-emphasized output.
Sample Rate: 64 kHz to 512 kHz, depending on processing being performed.
Noise: Output noise floor will depend upon how much gain the processor is set for (Limit Drive, AGC Drive, Two-Band Drive, and/or Multi-Band Drive), gating level, equalization, noise reduction, etc. It is primarily governed by the dynamic range of the A/D converter, which has a specified over-load-to-noise ratio of 110 dB. The dynamic range of the digital signal processing is 144 dB.
Total System Distortion (de-emphasized, 100% modulation): <0.01% THD, 20 Hz - 1 kHz, rising to <0.05% at 15 kHz. <0.02% SMPTE IM Distortion.
Total System Separation: >55 dB, 20 Hz - 15 kHz; 60 dB typical.
Polarity (Two-Band and Bypass Modes): Absolute polarity maintained. Positive-going signal on input will result in positive-going signal on output.

Installation

Delay

Defeatable Analog FM Processing delay: 16.2 seconds (maximum), adjustable in one-sample increments at 64 kHz sample rate to allow the delays of the analog and digital paths in the HD Radio system to be matched at the receiver output.
Minimum Processing Delay: Processing structure dependent. Typically 17 ms for normal latency 5-band, 13 ms for low-latency 5-band, 3 ms for ultra-low-latency 5-band, and 17 or 22 ms for 2-band, depending on crossover structure chosen.

Analog Audio Input

Configuration: Stereo.
Impedance: >10kΩ load impedance, electronically balanced .
Nominal Input Level: Software adjustable from -4.0 to +13.0 dBu (VU).
Maximum Input Level: +27 dBu.
No jumper selection available for 600Ω. Through-hole pads are available on I/O module for user-installed 600Ω termination.
Connectors: Two XLR-type, female, EMI-suppressed. Pin 1 chassis ground, Pins 2 (+) and 3 electronically balanced, floating and symmetrical.
A/D Conversion: 24 bit 128x oversampled delta sigma converter with linear-phase anti-aliasing filter.
Filtering: RFI filtered, with high-pass filter at 0.15 Hz.

Analog Audio Output

Configuration: Stereo. Flat or pre-emphasized (at 50 microseconds or 75 microseconds), software-selectable.
Source Impedance: 50Ω, electronically balanced and floating.
Load Impedance: 600Ω or greater, balanced or unbalanced. Termination not required, or recommended.
Output Level (100% peak modulation): Adjustable from -6 dBu to +24 dBu peak, into 600Ω or greater load, software-adjustable.
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, 88.1 kHz, and 96 kHz automatically selected.
Connector: XLR-type, female, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 transformer 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.

Digital Audio Outputs

Configuration: Two outputs, each stereo per the AES3 standard. The outputs can be independently set to emit the analog FM 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). Each output can apply J.17 pre-emphasis if desired.
Sample Rate: Internal free running at 32 kHz, 44.1 kHz, 48 kHz, 88.1 kHz, or 96 kHz, selected in software. Can also be synced to the AES3 SYNC input or the AES3 digital input at 32 kHz, 44.1 kHz, 48 kHz, 88.1 kHz, and 96 kHz, as configured in software.
Word Length: Software selected for 24, 20, 18, 16 or 14-bit resolution. Optionally, first-order highpass noise-shaped dither can be added; dither level is automatically adjusted appropriately for the word length.
Connector: XLR-type, male, EMI-suppressed. Pin 1 chassis ground, pins 2 and 3 transformer balanced and floating, 110Ω impedance.
Output Level (100% peak modulation): -20.0 to 0.0 dBFS software controlled.
Filtering: RFI filtered.

Digital Sync Input

Configuration: Used for synchronization of either or both AES3 signals to an external reference provided at this input.
Sampling Rate: 32 kHz, 44.1 kHz, 48 kHz, 88.1 kHz, and 96 kHz, automatically selected.
Connector: XLR-type, female, EMI-suppressed. Pin 1 chassis ground, Pins 2 and 3 transformer balanced and floating, 110Ω impedance.
Filtering: RFI filtered.

Composite Baseband Output

Configuration: Two outputs, each with an independent software-controlled output level control, output amplifier and connector.
Source Impedance: 0 voltage source or 75Ω, jumper-selectable. Single-ended, floating over chassis ground.
Load Impedance: 37Ω or greater. Termination not required or recommended.
Maximum Output Level: +12.0 dBu (8.72 Vpp).
Minimum Output Level: -12 dBu (0.55 Vpp) for 0.5 dB adjustment resolution.
Pilot Level: Adjustable from 6.0% to 12.0%, software controlled.
Pilot Stability: 19 kHz, ±0.5 Hz (10 degrees to 40 degrees C).
D/A Conversion: 24-bit
Signal-to-Noise Ratio: <= -85 dB (Bypass mode, de-emphasized, 20 Hz - 15 kHz bandwidth, referenced to 100% modulation, unweighted).
Distortion: <= 0.02% THD (Bypass mode, de-emphasized, 20 Hz - 15 kHz bandwidth, referenced to 100% modulation, unweighted).
Stereo Separation: At 100% modulation = 3.5Vpp, > 60 dB, 30 Hz - 15 kHz. At 100% modulation = 1.0 - 8.0 Vpp, > 55 dB, 30 Hz - 15 kHz.
Crosstalk-Linear: <= -80 dB, main channel to sub-channel or sub-channel to main channel (referenced to 100% modulation).
Crosstalk-Non-Linear: <= -80 dB, main channel to sub-channel or sub-channel to main channel (referenced to 100% modulation).
38 kHz Suppression: >= 70 dB (referenced to 100% modulation).
76 kHz & Sideband Suppression: >= 80 dB (referenced to 100% modulation).
Pilot Protection: -60 dB relative to 9% pilot injection, ±250 Hz (up to 2 dB composite limiting drive).
Subcarrier Protection (60-100 kHz): >= 70 dB (referenced to 100% modulation; with up to 2 dB composite limiting drive; measured with 800 line FFT analyzer using "maximum peak hold" display).
57 kHz (RDS/RBDS) Protection: -50 dB relative to 4% subcarrier injection, ±2.0 kHz (up to 2 dB composite processing drive).
Connectors: Two BNC, floating over chassis ground, EMI suppressed.
Maximum Load Capacitance: 0.047µF (0Ω source impedance). Maximum cable length of 100 feet / 30 meters
RG-58A/U.
Filtering: RFI filtered.

Subcarrier (SCA) Inputs

Configuration: Subcarrier inputs sum into composite baseband outputs before digitally controlled composite attenuator.
Impedance: >600Ω
SCA Sensitivity (Both Inputs): Variable from 220 mV pp to >10 V pp to produce 10% injection. Sensitivity is adjustable by an internal PC-board-mounted trim pot.
Connectors: Two BNC, unbalanced and floating over chassis ground, EMI suppressed.
19 kHz Pilot Reference: SCA2 input jack can be jumpered to provide a 19 kHz pilot reference output or to serve as a second SCA input.

Remote Computer Interface

Supported Computer and Operating System: IBM-compatible PC running Microsoft Windows® 2000 (SP3 or higher) or XP.
Configuration: TCP/IP protocol via direct cable connect, modem, or Ethernet interface. Suitable null modem cable for direct connect is supplied. Modem and other external equipment is not supplied.
Serial Connectors: RS-232 port (3) DB-9 male, EMI-suppressed. Serial Connector 1 uses PPP to provide for direct or modem connection to the 8500 PC Remote application. Serial Connector 2 supports communication to a computer or remote control system via simple ASCII commands for administration and recalling presets. Serial Connector 3 is reserved for future developments.
Ethernet Connector: Female RJ45 connector for 10-100 Mbps networks using CAT5 cabling. Native rate is 100 Mbps. Provides for connection to the 8500 PC Remote application through either a network, or, using a crossover Ethernet cable, directly to a computer.
Ethernet Networking Standard: TCP/IP.

Remote Control (GPI) Interface

Configuration: Eight (8) inputs, opto-isolated and floating.
Voltage: 6 - 15V AC or DC, momentary or continuous. 9VDC provided to facilitate use with contact closure.
Connector: DB-25 male, EMI-suppressed.
Control: User-programmable for any eight of user presets, factory presets, bypass, test tone, stereo or mono modes, analog input, digital input.
Filtering: RFI filtered.

Power

Voltage: 100-132 VAC or 200-264 VAC, switch-selected on the rear panel, 50-60 Hz, 50 VA.
Connector: IEC, EMI-suppressed. Detachable 3-wire power cord supplied.
Grounding: Circuit ground is independent of chassis ground' can be isolated or connected with a rear panel switch.
Safety Standards: ETL listed to UL standards, CE marked.

Environmental

Operating Temperature: 32 to 122 F / 0 to 50 C for all operating voltage ranges.
Humidity: 0-95% RH, non-condensing.
Dimensions (W x H x D): 19" x 1.75" x 14.25" / 48.3 cm x 4.4 cm x 36.2 cm. One rack unit high.
Humidity: 0-95% RH, non-condensing.
RFI / EMI: Tested according to Cenelec procedures. FCC Part 15 Class A device.
Shipping Weight: 19 lbs / 8.7 kg

Warranty

Two Years, Parts and Service: Subject to the limitations set forth in Orban's Standard Warranty Agreement.

Because engineering improvements are ongoing, specifications are subject to change without notice.

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