Specifications
Performance
Frequency Response (PROOF mode): Strapped for preemphasized output, follows standard 75us (or 50us) preemphasis curve ±0.75dB, 50-15,000Hz. Strapped for flat output, ±0.75dB, 50-15,000Hz.
Noise: -75dB referenced to 100% modulation, 50-15,000Hz; -81dB typical.
Total system distortion (PROOF mode, deemphasized, 100% modulation): <0.25% THD, 50-15,000Hz; 0.02% typical. <0.1% SMPTE Intermodulation Distortion.
System separation: >50dB, 50-15,000Hz; 60dB typical.
Installation
Audio Input
Configuration: Left and Right.
Impedance: >10k ohm load impedance, electronically balanced by true instrumentation amplifier. Requires balanced source £600 ohms. Common mode rejection >60dB @50-60Hz. Sensitivity: -30dBm to + 10dBm to produce 10dB "Master Band" gain reduction @ 1kHz.
Audio Output
Configuration: Left and right or sum and difference, selectable with internal jumpers; preemphasized or flat, selectable with internal jumpers. Impedance: 370 ohm source impedance, independent of OUTPUT ATTEN setting, balanced. Recommended load impedance 600 ohms ±20%. Peak Output Level: Adjustable from -infinity.dBm to >+20dBm with 15-turn OUTPUT ATTEN controls. Output clipping level + 26dBm/600 ohms.
Connector: Barrier strip (#5 screw), EMI suppressed.
Remote Control
Function: Selects loudness Controller ON/OFF.
Voltage: 6 to 24V AC or DC, momentary or continuous, optically isolated.
Connector: Barrier strip (#5 screw).
Remote Gain Reduction
Meter Output
Configuration: Negative DC voltage proportional to total master gain reduction. Scale approximately -0.33V/dB, source impedance 8.87k ohms.
Connector: Barrier strip (#5 screw).
Power:115/230 VAC (switch selectable), ±15%, 50-60Hz; 31VA. IEC mains connector with detachable 3-wire "U-Ground" power cord supplied. Leakage to chassis <0.5mA. AC is EMI suppressed.
Ground: Circuit ground is independent of chassis ground; both appear on terminal strip on rear panel for strapping as required.
Dimensions: 19" (48.3cm) W, 7" (17.8 cm) H, 12.5" (31.2cm) D. 4 rack units.
Environmental: Operating temperature range 0-50 degrees Celsius (32-122 degrees F). Humidity 0-95% RH, non-condensing.
Circuitry
Input Conditioning
Highpass filter: Third-order Chebychev with 30Hz cutoff and 0.5dB passband ripple; -0.5dB @ 30Hz, -10.5dB @ 20Hz, -31.5dB @ 10Hz.
Phase Scrambler: Allpass network makes peaks more symmetrical to best utilize the symmetrical peak overload characteristics of the FM medium.
Crossover
(US Patent No. 4,249,042)
Control: 6dB/octave, 200Hz.
Program: 12dB/octave, 200Hz, in unique "distributed crossover" configuration.
"Master Band" Compressor
Attack Time: Approximately 1 ms.
Release Time: Program controlled; varies according to program dynamics and amount of gain reduction. Process can be scaled fast or slow with continuously variable RELEASE TIME control. Employs delayed release for distortion reduction.
Threshold of compression: Controlled by left and right input attenuators.
Operation: Gains of left and right channels track to avoid stereo perspective shift.
Total harmonic distortion (at VCA output, OPERATE mode, RELEASE TIME control centered): <0.1%, 200-15,000Hz, +10 to -15dB gain reduction.
Available gain reduction: 25dB.
"Bass Band" Compressor
Attack Time: Program controlled.
Release Time: Program controlled. Employs delayed release for distortion reduction.
Operation: Gains of left and right channels track to avoid stereo perspective shift.
Total Harmonic Distortion (At VCA output, OPERATE mode): <0.1%, 50-200Hz, +10 to -20dB gain reduction.
Available Gain Reduction: 30dB.
Bass Coupling (US Patent No. 4,249,042): Enables gains of "Bass Band" to track gain of "Master Band" to any degree, from identical tracking to fully independent operation. Adjustable with BASS COUPLING control.
High Frequency Limiter
Attack time: Approximately 5ms.
Release time: Approximately 20ms. Employs delayed release for distortion reduction.
Threshold of HF limiting: User-adjustable over 3dB range to meet user requirements.
Operation: Left and right channels operate independently to prevent high frequencies in one channel from causing audible timbre modulation in opposite channel.
Hilbert-Transform Clipper
(US Patent No. 4,495,643)
Bandwidth: 15.4kHz.
Distortion Characteristics:<2.5% THD produced by individual frequencies 30-4,000Hz when driving Hilbert-Transform clipper to 6dB beyond threshold of limiting. Further distortion cancellation assures that, for any input including program material, distortion components in the frequency range 0 to 2,200Hz are canceled better than 30dB below overshoot compensator threshold. With drive frequencies above 4,000Hz, characteristics revert to those of a "hard" clipper.
Amount of Clipping: User-adjustable over 6dB range.
Frequency-Contoured Side-Chain (FCS) Overshoot Compensator
(US Patent No. 4,460,871)
Operation: The FCS circuit is best thought of as a "bandlimited safety clipper." It operates like a hard clipper, but without producing out-of-band frequency components. It is followed by a safety clipper, aligned so that it is almost never active, fully preserving the bandlimiting provided by the FCS circuit.
Peak Modulation Control: Within ±2% on typical program material; ±3.5% worst-case.
Sinewave modulation ability: 93% modulation (0.6dB below maximum overshoot level) at all frequencies.
"Proof" Test Mode
Compressor: Defeats "Master" and "Bass" gain reduction control; switches "gate" ON to force unit into 10dB gain reduction (0dB on GR meter).
Limiter: Defeats HF limiter, Hilbert-Transform Clipper, FCS Overshoot Compensator, and safety clipper.
Warranty
One year, parts and labor. Subject to limitations set forth in Orban's Standard Warranty Agreement.
Specifications subject to change without notice.