SHURE FP23
Owner's Manual

Model FP23 User Guide Microphone Preamplifier
General Description
The Shure FP23 is a portable, battery-powered microphone preamplifier with phantom power. Designed for high bandwidth 96k/24 digital production, this studio-quality mic preamp is ideal for critical radio, television, and film production applications. With its rugged mechanical and electrical construction, compact size, and high-quality components, the FP23 is extremely durable and easy to use. This highly reliable mic preamp will provide years of superb audio performance under the most punishing field conditions.

Specifications
Gain 0 dB to 66 dB input to output, switch selectable Gain Accuracy +0.6, �0.1 dB with reference to front panel gain markings (150 � source, 100k � load impedances) Frequency Response (see graph below) 20 Hz � 22 kHz, +0.1, �0.5 dB �1 dB at 50 kHz (relative to 1 kHz level with 150 � source) Equivalent Input Noise �126 dBu (�128 dBV) maximum (150 � source, flat weighting, 22 Hz � 22 kHz bandwidth for gain settings of 36 dB or greater) Output Clipping Level +22 dBu minimum with 100 k� load +20 dBu minimum with 600 � load Input Clipping Level +4 dBu minimum at the 0 or +18 dB gain setting Dynamic Range 122 dB minimum at the +18 dB gain setting THD + Noise 0.05% maximum (from 50 Hz to 22 kHz @ +4 dBu output level, 22 Hz � 22 kHz filter bandwidth, +46 dB gain setting) Common Mode Rejection Ratio: 100 dB minimum at 80 Hz 60 dB minimum at 10 kHz Input Transformer-balanced, 2000 � input impedance Output Transformer-balanced, 130 � output impedance Low Cut 80 Hz or 160 Hz (switch selectable), 6 dB per octave Phantom Power 12V or 48V (switch selectable) per DIN 45 596 Limiter Limits to +17 dBu output level 10:1 limiting ratio 5 ms attack time, 100 ms release time Amber/Red LED indicates limiting/clipping Internal Voltage Rails +15 V and �15 V, regulated Power 2 AA batteries, 24 hours life typical with +4 dBu signal into 600 �, no phantom power Power LED Green indicates power and good battery. Red indicates power and low battery. LED turns red when approximately 4 hours of battery life remain. Polarity Mic input to line output is non-inverting Operating Temperature Range �18 to 57 degrees C 0 to 135 degrees F

Features
Audio performance
� Maximum of 66 dB of gain, adjustable in eleven discrete steps for accurate, repeatable gain settings. � Dynamic range exceeding 120 dB. � 20 Hz to 50 kHz audio bandwidth. � High immunity to RF interference due to transformers, RF filtering, and all-metal construction. � High current line output driver capable of driving very long cable runs.

Transformer balanced
� Premium-quality input transformer provides superior sonic quality and freedom from interference problems. � Custom-designed output transformer provides line driving ability with freedom from interference problems.

Limiter
� Extended range peak limiter uses dual opto-isolators, making the unit virtually �unclippable.�

Battery power
� Internal battery power (two AA) for convenient, low cost power. � Battery life greater than 24 hours.

Durable mechanical construction
� High strength extruded aluminum chassis with protective metal end rails to withstand punishing field conditions. � Easy access battery compartment for quick battery changes.

Phantom power
� Selectable 48-volt and 12-volt phantom power for condenser microphones.

High pass filter
� Two corner frequency settings.

©2000, Shure Incorporated 27A8726 (Rev. 1)

Printed in U.S.A.