User-Friendly Interface

• An LCD and full-time LED meters make setup, adjustment and programming of OPTIMOD-FM easy—you can always see the metering while you’re adjusting the processor. Navigation is by dedicated buttons, soft buttons (whose function is context-sensitive), and a large rotary knob. The LEDs show all metering functions of the processing structure (Two-Band or Five-Band) in use.

Absolute Control of Peak Modulation

• The 8300 provides universal transmitter protection and audio processing for FM broadcast. It can be configured to interface ideally with any commonly found transmission system in the world.

• The 8300 provides pre-emphasis limiting for the two standard pre-emphasis curves of 50µs and 75µs. Its pre-emphasis control is seldom audibly apparent, producing a clean, open sound with subjective brightness matching the original program.

• The 8300 achieves extremely tight peak control at all its outputs—analog left/right, AES/EBU left/right, and composite baseband.

• By integrating the stereo encoder with the audio processing, the 8300 eliminates the overshoot problems that waste valuable modulation in traditional external encoders. The stereo encoder has two outputs with independent level controls, each capable of driving 75 ohms in parallel with 47,000pF, (100ft/30m of RG-59 coaxial cable).

• The 8300 prevents aliasing distortion in subsequent stereo encoders or transmission links by providing bandwidth-limiting and overshoot-compensated 15 kHz low-pass filters ahead of the 8300’s audio outputs and stereo encoder.

• Anti-aliased clippers running at 256 kHz sample rate prevent any trace of “digital clipper” sound.

Flexible Configuration

• The 8300 includes analog and AES/EBU digital inputs and outputs. Both digital input and digital output are equipped with sample-rate converters and can operate at 32 kHz, 44.1 kHz, 48, 88.2, and 96 kHz sample rates. The pre-emphasis status and output levels are separately adjustable for the analog and digital outputs.

• The 8300 has an internal, DSP-based stereo encoder (with a patented “half-cosine interpolation” composite limiter operating at 512 kHz sample rate) to generate the pilot tone stereo baseband signal and control its peak level. The composite limiter is a unique, “you can only do this in DSP” process that beats composite clippers by preserving stereo imaging while fully protecting the stereo pilot tone, RDS/RBDS, and subcarriers.

• The analog inputs are transformerless, balanced 10k ohm instrumentation-amplifier circuits, and the analog outputs are transformerless balanced, and floating to ensure highest transparency and accurate pulse response.

• The 8300 has two independent composite baseband outputs with digitally programmable output levels. Robust line drivers enable them to drive 100 feet of RG-59 coaxial cable without audible performance degradation.

• The 8300 has two subcarrier inputs that are mixed with the output of OPTIMOD-FM’s stereo encoder before application to the composite output connectors. One input can be re-jumpered to provide a 19 kHz pilot reference output. The other input has an internal level trim to accommodate subcarrier generators with output levels as low as 220 mV.

• The 8300 precisely controls the audio bandwidth to 15 kHz. This prevents overshoots in uncompressed digital links operating at a 32 kHz sample rate and prevents interference to the pilot tone and RDS (or RBDS) subcarrier.

• The 8300 has a defeatable multiplex power limiter that controls the multiplex power to ITU-R BS412 standards. An adjustable threshold allows a station to achieve maximum legal multiplex power even if the downstream transmission system introduces peak overshoots into the 8300-processed signal. Because this limiter closes a feedback loop around the audio processing, it allows the user to adjust the processor’s subjective setup controls freely without violating BS412 limits, regardless of program material. The multiplex power limiter acts on all outputs (not just the composite output) and works by adjusting the thresholds in the multiband compressor instead of adding another wideband gain control stage. The limiter is thus entirely multiband, which minimizes spectral gain intermodulation. It reduces clipper drive when it reduces power, simultaneously reducing clipping distortion.

• All input, output, and power connections are rigorously RFI-suppressed to Orban’s traditional exacting standards, ensuring trouble-free installation.

• The 8300 is designed and certified to meet all applicable international safety and emissions standards.

• The 8300 is HD FM Radio ready. A future software upgrade will allow you to route processing optimized for netcasts and HD FM Radio to the AES/EBU output, while the analog and composite outputs continue to supply processing optimized for the FM analog channel. All 8300 hardware already supports this extra functionality, which will be particularly useful for broadcasters who simulcast netcasts with their on-air program stream and who want to maximize netcast quality at any bit-rate. [HD FM™ is a trademark of iBiquity Corp.]

Adaptability through Multiple Audio Processing Structures

• A processing structure is a program that operates as a complete audio processing system. Only one processing structure can be on-air at a time. OPTIMOD-FM realizes its processing structures as a series of high-speed mathematical computations made by Digital Signal Processing (DSP) chips.

• The 8300 features three processing structures: Optimum Five-Band (or “Multiband”; 15 ms delay) for a consistent, “processed” sound, free from undesirable side effects, Low-Latency Five-Band (5 ms delay) for environments where talent monitors live off-air and they object to the delay of Optimum Five-Band, and Two-Band for a transparent sound that preserves the frequency balance of the original program material. A special Two-Band preset creates a no-compromise “Protect” function that is functionally similar to the “Protect” structures in earlier Orban digital processors. The Optimum Five-Band and the Two-Band structures can be switched via a mute-free crossfade; the Low Latency Five-Band structure causes a very brief audio mute when activated.

• The 8300 can increase the density and loudness of the program material by multiband compression, limiting, and clipping. This improves the consistency of the station’s sound and increasing loudness and definition remarkably, without producing unpleasant side effects.

• The 8300 rides gain over an adjustable range of up to 25dB, compressing dynamic range and compensating for both operator gain-riding errors and gain inconsistencies in automated systems.

• The 8300’s Two-Band processing structure is phase-linear to maximize audible transparency.

• The 8300 can import and run any 8400 “LL” (Low-Latency) preset via the 8300 PC Remote application. This means that you can use an 8400 to develop presets for 8300, provided you do not use 8400 features not supported by the 8300. (If you try to import an 8400 preset that uses features unsupported by 8300, the 8300 will interpret that preset as best it can by using the available 8300 features—see the 8300 Operating Manual for details.)

Controllable

• The 8300 can be remote-controlled by 5-12V pulses applied to eight programmable, optically isolated “general-purpose interface” (GPI) ports.

• 8300 PC Remote software is a highly graphical application that runs under Windows 2000 and XP. It communicates with a given 8300 via TCP/IP over modem, direct serial, and Ethernet connections. You can configure PC Remote to switch between many 8300s via a convenient organizer that supports giving any 8300 an alias and grouping multiple 8300s into folders. Clicking an 8300’s icon causes PC Remote to connect to that 8300 through an Ethernet network, or initiates a Windows Dial-Up or Direct Cable Connection if appropriate. The PC Remote software allows the user to access all 8300 features and allows the user to archive and restore presets, automation lists, and system setups (containing I/O levels, digital word lengths, GPI functional assignments, etc.).

• A Bypass Test Mode can be invoked locally or by remote control to permit broadcast system test and alignment or “proof of performance” tests.

• The 8300 contains a versatile real-time clock, which allows automation of various events (including recalling presets) at pre-programmed times.

• The 8300 contains a built-in line-up tone generator, facilitating quick and accurate level setting in any system.

• The 8300 software can be upgraded remotely through its serial port (connected to an external modem), or Ethernet port, or locally (by connecting a Windows^® computer to its serial port through the supplied null modem cable) and running Orban-supplied downloadable upgrade software.