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Preco launches OPTIMOD-FM 8600 digital audio processor into Britain

Orban Optimod-FM 8600 digital audio processor

Preco announces a major new addition to the Orban range of audio dynamics processors. Based on the established Optimod-FM 8500, the Optimod-FM 8600 is designed to optimise FM channel sound while delivering crisp, clean, CD-like audio to DAB and netcast audiences. Dramatically improved peak limiter technology decreases distortion while increasing transient punch and high-frequency power handling capacity.

FM and digital media processing paths split after the 8600's stereo enhancer and AGC. Dual equalisers, multiband compressors and peak limiters allow the analog FM and digital media processing to be optimised separately. A second-generation multiplex power controller yields the best possible coverage while complying fully with the ITU BS 412 standard. This can be adjusted to maximise loudness within the constraints of BS 412 or to produce less gain change at slightly lower loudness. New for the 8600 is the ability to apply MPX power gain reduction after the amplitude clippers.

The 8600 precisely controls the audio bandwidth of its analog FM processing to 16.5 kHz. This prevents significant overshoots in uncompressed digital links operating at a 44.1 kHz or high sample rate and prevents interference to the pilot tone and RDS (or RBDS) subcarrier. Bandwidth of the 8600's digital radio output is adjustable in 1 kHz increments between 15 and 20 kHz.

More than 20 format-specific factory presets are incorporated, including new 'MX' configurations designed by Bob Orban and Greg Ogonowski to exploit the exciting possibilities inherent in the 8600's new peak limiter technology. These can be customised with single-knob less/more adjustment or via more than 60 advanced controls. Custom presets for the OPTIMOD-FM 8500, 8400, 8300, 5500 or 5300 can be imported into the 8600.


Up to 16.2 seconds of delay can be applied independently to the analog output, digital outputs, and composite output, in any combination. All outputs configured for delay have the same amount of delay applied to them. Once set, this delay remains the same regardless of which processing preset is active.

The 8600 provides pre-emphasis limiting for the internationally used 50 and 75 microsecond pre-emphasis curves. Compared to its predecessor, the new clipping/pre-emphasis-control technology preserves 2.5 to 3 dB more frequency energy while significantly reducing audible clipping distortion at all frequencies. This produces a clean, open sound whose subjective brightness more closely matches the original programme.

Programmable contact-closure (GPI) control plus ASCII terminal control via the 8600's RS232 serial and Ethernet ports give freedom to interface the 8600 with a broadcast facility's remote control infrastructure. Supplied as standard is a PC application compatible with Microsoft Windows 2000 and higher, allowing remote control of multiple 8600 processors via TCP/IP.

The 8600's optional DSP-based stereo encoder and composite limiter deliver an FM analog signal that is clean and perfectly peak-limited, with full spectral protection of subcarriers and RDS/RBDS regardless of the amount of composite limiting.

For pure analog FM broadcasters, an 8600-FM model without digital radio processing is available at lower cost. Also available is an upgrade kit for existing 8500 and 8500-FM models. This is easily installed in the field by replacing the DSP board and CPU module, requiring no soldering or special tools.


About Preco

Founded in 1983, Preco (Broadcast Systems) Ltd is one of Britain's largest and most experienced suppliers of equipment to the television and radio broadcast industry. Preco is sole UK distributor for 25-Seven, 360 Systems, AVT, Chromatec, Cobalt, Cooltouch, D & R, Henry Engineering, Lawo, Logitek, O.C. White, Orban, Ross Video, Telos, Teranex, Tieline, Ward Beck and Yellowtec. Preco's customers include the BBC, BSkyB, Bauer Radio, Global Radio, ITN, Radio Investments, Wireless Group and a large number of independent radio stations. Preco also supplies the security, event management and teleconferencing markets.