Dc Operation: 27 Vdc nominal at 27 mA typical no-signal,
30 mA typical at 0 VU (+4 dBm) output; 21.5 Vdc minimum;
battery life approximately 10 hours with alkaline batteries
at + 4 dBm output in continuous use; three 9-volt bat-
teries, type NEDA 1604A (Duracell MN1604 or Eveready 522
recommended)
Temperature Range
Operating: -18O to 57OC (0° to 135OF)
Storage: -2g0 to 71°C (-20° to 160°F)
Dimensions
79.5 mm H x 310 mm W x 230 mm D (3-118 in. x 12-7132 in. x
9-1132 in.)
Weight
INPUT LEVEL IMIC I1 IN dBV Net: 2.75 kg (6 Ib 1 02)
Packaged: 3.25 kg (7 Ib 3 oz)
COMPRESSION SYSTEM Certifications
INPUT-OUTPUT CHARACTERISTICS
Listed by Underwriters Laboratories Inc.; listed by Cana-
FIGURE 1 dian Standards Association as Certified
Gated Memory
Threshold: -90.5 dBV typical at maximum input
gain (mic); -40.5 dBV typical at max-
imum input gain (line) CONTROLS AND CONNECTORS
Recovery: In "hold" position, less 20 than dB gain Power Off-On Switch: applies power to the FP51 circuitry.
recovery after minute 1 Channel Levellcue Rotary Controls: adjust individual input
VU Meter channel signal levels. Each channel can be cued by pulling the
Dual-range, 3-function (output level in dB, gain reduction in control knob outward the to detent position, rotating knob the
dB, battery check), illuminated (ac operation only) to the desired level, and pushing the knob inward to activate
'the channel.
Gated MemorylPeak Indicator
With meter switch in VU position, lights 6 dB below clipping; Lo Cut Filter Slide Switches: reduce unwanted low-frequency
with meter switch in Comp position, lights when gated signals such as wind noise by 6 dB per octave at 150 Hz.
memory is "holding" Master Rotary Control: determines mixed output level out- at
Noise put connector. The control also sets the tone oscillator level
Equivalent lnput Noise: - 129 dBV (low-impedance when the Tone Osc switch turned is on.
microphone, 150 ohms, 300 to 20,000 Hz) into 600-ohm load Gated MemorylPeak LED: indicates, in gated memory mode,
at full gain that gated memory is "holding" prior amount of compression
Equivalent lnput Hum and Noise: -127 dBV (low- during low a input signal, turns and off when input signal is
impedance microphone, 150 ohms, 20 to 20,000 Hz) into above compression threshold. In peak mode, the LED indi-
600-ohm load at full gain cates approaching program overload. It is activated by the
shortest transient peak, but remains on long enough to pro-
Output Noise: -77 dBV maximum (output control full vide easy recognition. The chart below shows the effect of
counterclockwise [off]), -40 dBV maximum (output control
Compressor and Gated Memory switches on indicator opera-
full clockwise [on]) (input control down, 300 to 20,000 Hz) tion.
Output Hum and Noise: -75 dBV maximum (output con-
trol down), -38 dBV maximum (output control up, input con- GATED MEMORYIPEAK LED FUNCTIONS
trol down, 20 to 20,000 Hz)
Gated Memory off I Gated Memory on
Distortion
0.4% THD, 30 to 20,000 Hz at + 15 dBm output; 0.5% or less Compressor out No operation
IM distortion at + 15 dBm output into 600 ohms Compressor in Gated memory
Common Mode Rejection VU Meter: indicates 0 VU with a +4 dBm output (recom-
65 dB minimum with input of -20 dBV at 100 Hz mended for normal use to provide approximately 14 dB
Control Interaction headroom from operating level to clipping level) with VUlComp
Less than 1 dB with any control combination switch in VU position. Rear-panel VU Range +41+8 slide
switch permits changing to 0 VU = +8 dBm. With VUlComp
Overload and Shorting Protection
switch in Comp position, indicates compression due to input
Shorting outputs, even for prolonged periods, will cause no signal above threshold (lower meter scale). The VU meter is lit
damage; microphone input will not be damaged by signals
during ac operation only; therefore, illumination the serves as
up to 3V a visual alarm if the ac is interrupted and the unit has
Low-Cut Filters automatically switched to battery operation.
6 dB per octave rolloff at 150 Hz
Batt Check Momentary Push-button Switch: operates in con-
Phase junction with the VU meter to indicate battery condition. With
All outputs in phase with respect to all inputs. Pin is "high" 2 the Power switch on and the switch depressed, a new set of
with respect to pin 3; pin 1 is ground. Tip of mix bus jack in batteries will give about a + 2 VU indication. Battery condition
phase with pin 3. Tip and ring of headphone jacks in phase
is good if the reading is above 0 VU; a lower reading means
with pin 2 that new batteries are required for proper operation.
Tone Oscillator Gated Memory Slide Switch: disables the gated memory
1 kHz; + 15 dBm minimum at line output with output level function without affecting other operations.
full up Response Rate Rotary Control: adjusts the compression
Phantom Power system time constant to compensate for different types of pro-
30 Vdc nominal, 3.3k series resistance, automatically dis- gram material. In general, a faster setting (toward the
abled with input switch in Line position counterclockwise position) results a more constant in output
Operating Voltage level, but a more audible compression effect. Although the
Ac Operation: 120 or 240 Vac -r-10% (internally control setting is subjective, the following knob positions offer
selectable), 50160 Hz, 5.5W guidelines: speech -2; pop music -4; symphonic music- 7. |
ACEC
