GENERAL
The ILP-1 is a high-clipping level, low-noise preampli-
fier designed exclusively for use with Shure Models
SM90A, SM91A, SM98A, SM102B and SM102W, or for
use as a replacement preamplifier for older Models SM90,
SM91, and SM98. The ILP-1 connects to balanced micro-
phone inputs providing 11 to 52 Vdc phantom power. Two
switches on the ILP-1 allow you to set low-frequency re-
sponse (flat or rolloff at 12 dB/octave) and gain (0 or +10
dB). The low cut switch minimizes ambient low-frequency
noise from sources such as heating or air conditioner
fans.
The supplied mounting clamps hold the preamplifier in
place for permanent installations. Use either one or two
clamps depending on location and application.
SPECIFICATIONS
Frequency Response
Switch Setting
Gain (dB)
Flat
30 Hz to 20 kHz
(6 dB/octave rolloff below 30 Hz)
Rolloff
80 Hz to 20 kHz
(12 dB/octave rolloff below 80 Hz)
Gain (at 1 kHz, no load)
Switch Setting
Gain (dB)
0
–6.0 (
±
0.5 dB)
+10
+4.0 (+1.0, –1.5 dB)
Output Impedance
Rated at 150
Ω
(90
Ω
actual)
Output Noise (V
in
, grounded, no load)
–123 dBV rms typical, A-weighted
Output Clipping Level
GAIN SWITCH
LOAD
0
+10
150
Ω
0.0 dBV
–7.0 dBV
800
Ω
–13.0 dBV
–21.0 dBV
Electromagnetic Hum Sensitivity
–146 dBV equivalent in 1 millioersted field
Electrostatic Hum Pickup
–97 dBV typical, measured in 12 kV field
Polarity
Positive voltage on pin 3 relative to pin 1 of the input
connector produces positive voltage on pin 2 relative to
pin 3 of the output connector
Power Requirement
Phantom power: 11 to 52 Vdc at pins 2 and 3 relative
to pin 1
Dimensions
See Figure 1.
138 mm
(5 7/16 IN.)
20 mm
(13/16 IN.)
DIMENSIONS
FIGURE 1
Weight
170 grams (6.0 ounces)
Connectors
Input: mini 3-pin male (TB3M)
Output: 3-pin (male) XLR-type
Switches
Two recessed slide switches
(low frequency rolloff and 0/+10 gain)
Case
Steel, matte black enamel finished
Environmental Conditions
Operating Temperature: –19 to 57
°
C (–20 to 13
°
F)
Storage Temperature: –29 to 74
°
C (–20 to 168
°
F)
Relative Humidity: 0 to 95%
Model ILP-1 User Guide
27A8494 (Rev. 1)
E
2002, Shure Incorporated
Printed in U.S.A.
