Shure Stereo Microphone Mixer Model FP42 - Manual (Page 3)

3
is recommended for normal use to provide approximately 14 dB of
headroom from operating level to clipping level.
The VU meters are illuminated by a single cartridge-type, 6.3V in-
candescent lamp, operating well under its normal rating for a life ex-
pectancy of greater than 10,000 hours. The lamp is only lit for ac
operation. Consequently, the illumination serves as a visual alarm if
the ac is interrupted and the unit has switched to battery operation.
The VU meters are connected on the primary side of the output
transformer to assure protection from any dc level on a telephone
line.
Telephone interconnection
When using the FP42 connected directly to a telephone line, check
to see whether the telephone company requires an interface cou-
pler between the FP42 and the telephone line. If a coupler is re-
quired, make certain the coupler selected and the wiring arrange-
ment are in compliance with local telephone company regulations.
Connect the telephone line to the left or right Output connector and
turn the Pan controls so that the entire output signal is on the tele-
phone-connected output, or switch to mono operation.
Telephone Line Surge Protection
When using the FP42 connected directly to a telephone line subject
to lightning-induced voltage surges, the following part (commer-
cially available) can be installed across the output terminals to pro-
vide additional protection for output circuit components: Metal Ox-
ide Varistor, General Electric Co., Type No. V22ZA1.
SPECIFICATIONS
Frequency Response (ref 1 kHz)
30 to 20,000 Hz, +1, –3 dB
Voltage Gain (at 1 kHz)
OUTPUT
INPUT
LINE MICROPHONE MIX BUS PHONES PHONES (CUE)
Mic 90 dB 40 dB 25 dB 100 dB 85 dB
Line 40 dB –10 dB –25 dB 50 dB 35 dB
Mix Bus 55 dB 5 dB – 62 dB –
Inputs
IMPEDANCE (at 1 kHz) INPUT CLIPPING LEVEL
INPUT
FOR USE WITH ACTUAL
INPUT CLIPPING LEVEL
(at 1 kHz)
Mic 19–600 ohms 1k –40 to –5 dBV*
Line Less than 10k 66k +10 to +45 dBV*
Mix Bus 3.5k 3.5k 0 dBV
*Dependent on input control setting.
Outputs
IMPEDANCE (at 1 kHz)
OUTPUT CLIPPING LEVEL
OUTPUT
FOR USE WITH ACTUAL
OUTPUT CLIPPING LEVEL
(at 1 kHz)
Mic 150 ohms <1 ohm
–33 dBV min. across150
ohms
Line 600 ohms 185 ohms
+18 dBm min. across 600
ohms
Mix Bus 3.5k 3.5k –15 dBV min. across 3.5k
Headphones 8–2000 ohms 100 ohms +6 dBV min. across 200 ohms
Noise
Equivalent Input Noise: –129 dBV (low-impedance micro-
phone, 150 ohms, 300 to 20,000 Hz) into 600-ohm load at full
gain
Equivalent Input Hum and Noise: –127 dBV (low-impedance
microphone, 150 ohms, 20 to 20,000 Hz) into 600-ohm load at
full gain
Output Noise: –70 dBV maximum (output control full counter-
clockwise [off]), –55 dBV maximum (output control full clockwise
[on]) (input control down, 300 to 20,000 Hz)
Output Hum and Noise: –62 dBV maximum (output control
down), – 53 dBV max. (output control up, input control down, 20
to 20,000 Hz)
Distortion
0.4% or less THD, 30 to 20,000 Hz at + 15 dBm output; 0.5% or
less IM distortion at +15 dBm output into 600 ohms
Common Mode Rejection
65 dB minimum with input of – 20 dBV at 100 Hz
Control Interaction
Less than 1 dB with any control combination
Overload and Shorting Protection
Shorting outputs, even for prolonged periods, will cause no dam-
age; microphone input will not be damaged by signals up to 3V
Separation (left and right outputs)
40 dB minimum at 10 kHz; 50 dB minimum at 1 kHz
Low-Cut Filters
6 dB per octave rolloff at 150 Hz
Limiter
Threshold: Adjustable, +8 to +14 dBm
Attack Time: 3 msec typical
Recovery Time: 500 msec typical
Peak/Limiter Indicators
Limiter out: lights 6 dB below clipping
Limiter in: lights at onset of limiter action
Phase
All outputs in phase with all inputs. Pin 2 is “high” with respect to
pin 3; pin 1 is ground. Tip of mix bus jack in phase with pin 3. Tip
and ring of headphone jacks in phase with pin 2 of left and right
outputs, respectively.
Tone Oscillator
1 kHz; +18 dBm maximum at both outputs with Master level full
up
Phantom Power
30 Vdc nominal, 3.3k series resistance, automatically disabled
with input switch in Line position
Operating Voltage
Ac Operation: 120 or 240 Vac
±
10% (internally selectable),
50/60 Hz, 6W
Dc Operation: 27 Vdc nominal at 30 mA typical no-signal, 32 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 batteries, type NEDA 1604A
Temperature Range
Operating: –18
°
to 57
°
C (0
°
to 135
°
F)
Storage: –29 ° to 71 ° C (–20 ° to 160 ° F)
Dimensions
79.5 mm H x 310 mm W x 230 mm D
(3–1/8 in. x 12–7/32 in. x 9–1/16 in.)
Weight
Net: 2.95 kg (6 lb 8 oz)
Packaged: 3.45 kg (7 lb 10 oz)
Certifications
Listed by Underwriters Laboratories, Inc.; listed by Canadian
Standards Association as Certified
ACCESSORIES
The Model A16R Rack Panel Kit consists of a 19 in. x 3–1/2 in.
(483 mm x 89 mm) precut rack panel and necessary hardware for
rack-mounting the FP42 with its cover in place and end caps re-
moved in a standard 19” (483 mm) rack panel.