Shure FP24 User Manual

Model FP24 User Guide

Microphone Mixer

General Description

The Shure FP24 is a studio-quality two-channel, portable, stereo
microphone mixer. With assignable L-C-R inputs, built-in slate mi­crophone, 1 kHz tone oscillator , and headphone monitor, the FP24
is extremely flexible. Its impressive audio performance and com­prehensive features make it suitable for the front end of any studio
or field production system. Radio, television, and film production
engineers will especially value its compact size, sunlight-readable
LEDs, and rugged mechanical and electrical construction that
make it able to withstand extremes in the field.

Features

High Performance Microphone Inputs

• Maximum of 66 dB of gain (each input).

• Premium Lundahl input transformers provide superior audio

quality and freedom from interference problems.

• Sealed, conductive plastic potentiometers for long life and
reliable gain adjustment.

• Phantom power, selectable between 48 volts and 15 volts.

• Switchable low-cut filters with 80 and 160 Hz corner

frequencies, 6 dB per octave. Filters are inserted prior to
any active circuitry to maximize headroom.

• Inputs assignable to Left, Center (both left and right) or
Right

Audio Performance

• Dynamic range exceeding 1 10 dB.

• 10 Hz to 50 kHz audio bandwidth.

• Exceptionally low distortion characteristics.

• Discrete, 6-transistor, balanced output drivers provide signal

integrity over long cable runs.

Headphone Monitoring

• Switchable between program audio or external (stereo) tape
returns.

• High current headphone output has level control and peak
indicator.

Level Metering

• Dual-color LEDs indicate clipping and limiter activity for
each channel.

• Sunlight-readable, seven segment GaN LED output meters.

• 3-position LED brightness switch (intensity selector).

Audio Limiters

• “Unclippable” input peak limiters with adjustable limiter
threshold (each input).

• Dual mono or linked stereo limiter operation.

Flexible Powering

• Internal power from two AA batteries with easy access
battery compartment.

• Chassis-isolated 5 to 14 VDC input for easy external DC
powering.

• Power LED indicates low battery power.

Trouble-Free Design

• High-strength, extruded aluminum chassis with protective
metal end panels withstands punishing field conditions.

• All-metal connectors mount directly to the chassis for
durability and RF immunity .

• Free from “Pin 1” grounding problems.

• RF filtering on all inputs and outputs.

2005, Shure Incorporated

27A8727 (Rev. 1)

Printed in U.S.A.

Specifications

Gain:

Mic Input to Output, per channel, continuously variable

Output Gain Range

LINE –∞ – 66 dB

TAPE –∞ – 56 dB

Frequency Response:

20 Hz – 30 kHz, +0.2, –0.5 dB; –1 dB at 5 Hz, 50 kHz

(relative to 1 kHz level with 150 ohm source, gain controls set
at 50%)

Equivalent Input Noise:

–126 dBu (–128 dBV) minimum

(150 ohm source, flat weighting, 22 Hz – 22 kHz bandwidth,
gain control set at 50% or higher, phantom power off)

Input Clipping Level:

–10 dBu minimum

Output Clipping Level:

Line: +22 dBu minimum with 100k ohm load

+20 dBu minimum with 600 ohm load

Tape: +11 dBu (2.75 V RMS) minimum with 100k ohm load

Dynamic Range:

110 dB minimum

THD + Noise:

0.05% maximum
(from 50 Hz t o 2 2 kHz @ +4 dBu output level, 22 Hz – 22 kHz

filter bandwidth, gain control at 50%, phantom off)

Common Mode Rejection Ratio:

100 dB minimum at 80 Hz
60 dB minimum at 10 kHz

Channel Separation:

Greater than 80 dB at 1 kHz (gain controls set to 50%)

Inputs:

Transformer-balanced, 2k ohm input impedance

Outputs:

XLR: Active, impedance-balanced, 120 ohm output impedance
Tape (3.5 mm (

ground, 2.4k ohm output impedance

High Pass Filters:

80 Hz or 160 Hz (switch selectable), 6 dB per octave

Phantom Power:

15 V through 680 ohm resistors or 48 V through 6.8k resistors
(switch selectable)

1

/8 in.)): Unbalanced, tip–left, ring–right, sleeve–

Limiter:

Thresholds independently adjustable from
+6 dBu to +18 dBu

10:1 limiting ratio
5 ms attack time, 100 ms release time
Amber/Red LED indicates limiting/clipping
Dual mono or stereo linked

Internal Voltage Rails:

+15 V and –15 V, regulated

Metering:

7 segment GaN (Gallium Nitride) meter with 3 intensities
Peak responding

Power:

Internal: 2 AA batteries
External: 5 – 14 VDC via threaded coaxial connector* (5.5 mm

outer diameter , 2.1 mm inner diameter); Pin positive, sleeve neg­ative; V oltages above 14 VDC cause no damage to unit, but will
open an internal poly fuse that will reset when voltage is re­moved.

*Threaded coaxial connector provided for use with power sup­plies not equipped. For instructions on how to solder this connec­tor to a Shure PS20, see Figure 5.

Power LED:

Dual-color LED indicates following:
Green—external DC power or good battery.
Red—less than 1 hour of battery life remaining (with phantom

power off).

Polarity:

All inputs to all outputs, non-inverting.
Pin 2 of XLRs “hot” (to unbalanced inputs and outputs).

Operating Temperature Range:

0 to 70 degrees C (32 to 160 degrees F)

Dimensions:

43 mm x 94 mm x 140 mm (H x W x D) (1.7” x 3.7” x 5.5”)

Weight (FP24 only):

0.8 kg (1.8 lbs.)

Weight (packaged):

1.2 kg (2.6 lbs.)

EMC Certifications:

Meets FCC Part 15 Class B Emissions; Eligible to bear CE mark
(see conformance statement)

Optional Accesories

Balanced line-level-to-microphone-level

in-line adapter A15LA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

FP33/FP24 Interconnection Kit A33LK. . . . . . . . . . . . . . . . . . . .

Inline Polarity Inverter A15PRS. . . . . . . . . . . . . . . . . . . . . . . . . . .

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