Magnetic Film Recording System

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THIS PRODUCT IS NO LONGER IN PRODUCTION

The Inovonics 390 is an audio electronics package specifically intended for motion picture sound recording on sprocketed magnetic film. It was engineered to meet the needs of top-quality original installations, and to retrofit existing recording systems for a substantial improvement in performance.

The Inovonics 990 is a companion Power Supply used with the 390 system. It can power a maximum of 8 channel modules in a single system, and in addition to regular DC voltages, also contains the bias pilot oscillator and LINEUP mode circuitry.

Features


  • Modular design with complete Erase, Bias, Record, Reproduce and "Recordist Monitor" functions

  • Automatic Bias, Level and EQ Swithcing

  • OLX™ (Oxide Linearity eXtension) predicts, cancels and eliminates THD and IM distortions.

  • HFX™ (High Frequency eXtension) program-adaptive biasing

  • Two sets of non-interactive IN/OUT timing adjustments

  • LINEUP mode with front panel "trim" adjustments for Bias, Record Level and Record EQ.

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Specifications


Overall Frequency Response

  • 35mm/ ± 1.5dB, 25Hz - 20kHz
  • 16mm/ ± 2dB, 20Hz - 12kHz

Signal-to-Noise Ratio

  • in dB, referred to a “peak” flux level of 370nW/m, or 6dB above Operation Level
  • 35mm/ OVERALL(u’wtd -67/A-wtd -75)
  • 35mm/ STANDBY(u’wtd -74/A-wtd -82)
  • 16mm/ OVERALL(u’wtd -63/A-wtd -70)
  • 16mm/ STANDBY(u’wtd -70/A-wtd -77)

Distortion

  • Oxide-induced distortion will reach aproximately 1% THD at a fluid level of 290W/m, or approximately 4dB above Operating Level. (This depends on an oxide formulation.)
  • Distortion in the electronics is >0.1% at any level up to signal clipping. The electronics internal clipping points are at least 20dB above typical operating levels.

Equalization

35u-sec for 35mm tests, 70u-sec for 16mm, and a “flat” low frequency characteristic per the SMPTE Specification. Equalization presets are automatically switched with jumpers in plug-in head assemblies.

Line Input

Transformerless, electronically-balanced/bridging; appears at the back panel “XLR” female connector. Differential input impedance >10k-ohms; accepts nominal program line levels between -5dBu and +15dBu, +4dBu nominal. (0dBu = 0.775V r.m.s.). Common Mode Rejection >40dB.

Line and Recordist Monitor Outputs

Transformerless, electronically-balanced; appear at 600-Ohm source impedance; clipping level +24dBm into 600-Ohm load.

Erase Frequency

125kHz

Erasure

<75dB erasure of 500Hz signal recorded at or below oxide saturation.

Bias Frequency

250kHz

IN/OUT Timing

Separate, non-interactive adjustments for 35mm and 16mm film speeds. IN and OUT timing delays are each independently variable between 40 and 500ms.

Head Requirements

  • Erase: 2mH, ±10%, with >90% magnetic efficiency at 125kHz; dual-gap construction.
  • Record: 5mH, ±20%, with >80% magnetic efficiency at 250kHz; recommended gap spacer, 200u-inches.
  • Reproduce: (Recordist Monitor) 5mH, ±20%; recommendedgap spacer 200u-inches.

Power Requirements

The Model 390 Channel Modules each require a preregulated bipolar supply of ±118vdc at 350ma, and a 500kHz Erase/Bias “pilot” signal of 15 volts p-p. The Inovonics Model 990 Power Supply, which satisfies these requirements for a system of 8 channels or less, operates fro 115/230-volt AC mains, 50/60Hz, and draws about 120 Watts fully-loaded

Line Output

Balanced, transformer-isolated, with provision for balanced, transformerless operation if desired. May be adjusted for nominal line levels between +4 and +10dBm. Clipping level, +28dBm into 600-ohm load; +30dBmV into bridging inputs.

Size and Weight

  • 390 Channel Modules: 7 x 4.3 x 8”: 4lbs.
  • 990 Power Supply: 3.5 x 19 x 10” (2U); 17 lbs.
  • 999 Rack Frame: 7 x 19 x 8” (4U); 3lbs.