Shure ILP1 User Guide

GENERAL

The ILP-1 is a high-clipping level, low-noise preampli­fier 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 micro­phone inputs providing 11 to 52 Vdc phantom power. Two
switches on the ILP-1 allow you to set low-frequency re­sponse (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

Rolloff

(6 dB/octave rolloff below 30 Hz)

(12 dB/octave rolloff below 80 Hz)

30 Hz to 20 kHz

80 Hz to 20 kHz

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 (Vin, grounded, no load)

–123 dBV rms typical, A-weighted

Model ILP-1 User Guide

Output Clipping Level

LOAD

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.)

DIMENSIONS

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%

GAIN SWITCH

0 +10

(13/16 IN.)

FIGURE 1

20 mm

E2002, Shure Incorporated
27A8494 (Rev. 1)

Printed in U.S.A.

DISASSEMBLY

1. At the XLR-3 end of the preamplifier, turn the

slotted-head setscrew fully inward (counterclock­wise), and use a long-nose pliers to withdraw the

4. Re-install the four Phillips screws.

5. Resolder the three lead wires to the back of the
XLR-3 board as shown in Figure 2.

connector from the case.

2. Unsolder the three lead wires from the XLR-3 board.

3. Remove all four Phillips-head screws from the ILP-1
case (three on the switch side, one on the back).

4. Grasp the end cap and withdraw the cap assembly,
pc board assembly, and connecting wires and jacks
from the case.

REASSEMBLY

1. Make sure the pc board is seated in the slot of the

6. Replace the XLR-3 board-connector assembly in the

end cap and that no wires are pinched.

2. With the XLR-3 connecting wires foremost, feed the
end-cap-board assembly into the case. Take care
not to pinch the wires connecting the board to the
end cap.

7. Insert the connector into the case until the slotted

3. Rotate the assembly until the four holes for the Phil­lips screws line up with the holes in the case.

Reference Part Number Description Commercial Alternate

A1 90B4220 ILP-1 Preamplifier Assembly None
A2 90HZ2600 PC Board Assembly None
MP1 66A264 Preamp Switch Cover None
MP2 80A476 Mounting Clamp All States 3/4-HNB
P1 95A8077 Plug Assembly, Male, Mini TB3M
P2 90HV2600 XLR-3M Connector and PC Board Assembly None

XLR-3 PC BOARD TERMINAL WIRING

FIGURE 2

case, lining up the key in the connector with the slot
in the case. Take care not to engage the butterfly­shaped ground contact in the key slot, as this pre­vents the connector from seating properly.

setscrew can be seen through the case hole; then
tighten the setscrew by turning it clockwise.

NOTES:

1. All resistors 1/10 Watt, 1%, 0805
unless otherwise specified.

2. Electrolytic and Tantalum
capacitors shown in µF, tolerance
10% and 50 V or more unless
otherwise specified.

SHURE Incorporated Web Address: http://www.shure.com
5800 W. Touhy Avenue, Niles, IL 60714-4608, U.S.A.
In U.S.A., Phone: [phone] Fax: [phone]
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International Fax: [phone]