Circuit Description; Specifications - Shure VP88 User Manual

CIRCUIT DESCRIPTION

A block diagram of the VP88 is shown in Figure 5.

SPECIFICATIONS

Type
Single-point stereo (MS configuration) condenser
Frequency Response (See Figures 6 and 7)
40 to 20,000 Hz
Polar Pattern (See Figures 8 and 9)
Mid Cartridge: Cardioid (unidirectional)
Side Cartridge: Bidirectional
Output Impedance
Rated at 150 (100 Ω actual). Recommended minimum load im-
pedance: 800 Ω (may be used with loads as low as 150 Ω with
reduced clipping level)
Sensitivity (1 kHz, MS mode)
Open Circuit Voltage: –66 dB (0.5 mV) Mid. (Side level 1.6 dB
higher than Mid level) (0 dB=1 V/Pa)
Side Level (Stereo mode; relative to Mid level)
Low: –6.0 dB; Medium: –1.9 dB; High: +1.6 dB
Clipping Level (1 kHz)
800 Ω Load (less than 1% THD)
–12 dBV (0.25 V)(Mid output, 1% THD)
–10 dBV (0.30 V)(Side output, 1% THD)
150 Ω Load (less than 3% THD)
–25 dBV (0.06 V)(Mid output)
–19 dBV (0.11 V)(Side output)
Maximum SPL
800 Ω Load: 129 dB
150 Ω Load: 119 dB
Hum Pickup
–4 dB equivalent SPL in 1 millioersted field (60 Hz)
Self Noise (Mid, Side, Left and Right outputs; equivalent sound
pressure levels)
24 dB typical, A-weighted
28 dB typical, weighted per DIN 45405
Dynamic Range
105 dB (maximum SPL to A-weighted noise level)
Signal–to–Noise Ratio*
70 dB (IEC 651) at 94 dB SPL
*S/N ratio: difference between microphone output at 94 dB SPL and microphone self–noise A–
weighted.
VP88 CIRCUIT BLOCK DIAGRAM
FIGURE 5
Overvoltage Protection
Maximum External Voltage applied to Pins 2 through 5 with re-
spect to Pin 1:
Polarity
Positive pressure applied from any direction to the Mid cartridge or
from the left to the Side cartridge in the MS mode, or applied from
the front in the Stereo mode produces positive voltage on pin 2 rel-
ative to pin 3 (Mid/Left) and pin 4 relative to pin 5 (Side/Right).
Power
Phantom
Supply Voltage: 9 to 52 Vdc
Current Drain: 1.3 mA/output; 2.6 mA total
Battery
Type: 6 V cylindrical*
Life: 70 hours**
Current Drain: 2.4 mA total
*Silver oxide (NEDA 1406SOP), lithium (NEDA 5005L), alkaline (NEDA 1414A)
**Fresh silver oxide or lithium battery; 40 hours with alkaline
Environmental Conditions
Operating: –18
(Relative Humidity <90%)
Storage: –29
(Relative Humidity <80%)
Cables (see Figure 10)
Y-Splitter Cable (supplied): 0.76 m (30 in.) vinyl-jacketed, dual–
shielded, 2-conductor with 5-pin female XLR connector on mi-
crophone end and two 3-pin male XLR connectors on equip-
ment ends.
Microphone Extension Cable (Model C110; optional): 7.6 m
(25 ft.) vinyl-jacketed, shielded, 4-conductor with 5-pin male
XLR connector on one end and 5-pin female XLR connector on
other end.
Case
Brass and nickel-plated aluminum construction with stainless
steel grille. Finished in satin black vinyl enamel
Dimensions
See Figure 11
Net Weight
417 grams (14.7 oz) less battery and cable
4
±
75 Vdc
° ° ° °
to 57 C (0 to 135 F)
° ° ° °
to 74 C (–20 to 165 F)