Audio international PA-475-A User manual

7300 Industry Drive, North Little Rock, AR 72117
Phone: [phone] Fax: [phone]
www.audiointl.com
Installation Manual
Model #: PA-475-A (-B) (-C)
Audio Amplifier
Document #540021

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 2 of 12
Document Revision History
Rev. Level Date Description
IR 11/1997 Initial Release
A 11/1998 ECN #3004
B 3/1999 ECN #3427
C 4/2000 ECN #4675
Reference Documents
Document # Drawing # Description
N/A 521450 PA-475-A (-B) (-C) Outline Drawing
Service Bulletin List
Service
Bulletin # Subject Manual Revision Revision Date
Table of Illustrations
Illustration # Description Page #
1 Block Diagram – Typical Application 5
2 Reference Drawings 12
PROPRIETARY INFORMATION NOTICE: Despite any other copyright notice, this document and
information disclosed herein contains confidential, proprietary designs owned by Audio International, Inc.
Neither this document nor the data contained herein shall be reproduced, used or disclosed to anyone
without the written authorization of Audio International, Inc.

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 3 of 12
Table of Contents
Section Description Page
1.0 General Information ……………………………………………. 4
1.1 Introduction ……………………………………………………….. 4
1.2 Purpose of the Equipment ………………………………………. 4
1.3 Operational Features …………………………………………….. 4
1.4 Optional Equipment ……………………………………………… 4
2.0 Application ……………………………………………………….. 5
2.1 Introduction ……………………………………………………….. 5
2.2 Block Diagram –Typical Application …………………………… 5
3.0 Installation ……………………………………………………….. 6
3.1 Prior to Installation ……………………………………………….. 6
3.2 Unpacking and Inspection ………………………………………. 6
3.3 Cautions & Warnings …………………………………………….. 7
3.4 Wiring Requirements …………………………………………….. 7
3.5 Physical Characteristics………………………………………….. 8
3.6 Electrical Characteristics…………………………………………. 8
3.7 Mating Connector Information ……………..……………………. 9
3.8 Pinout Assignment Descriptions ………………………………... 9
3.9 Post-Installation Test …………………………………………….. 10
4.0 Troubleshooting Guide………………………………………… 10
5.0 Specifications …………………………………………………… 11
6.0 Reference Drawings ……………………………………………. 12

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 4 of 12
MODEL # PA-475-A (-B) (-C)
Audio Amplifier
1.0 General Information
1.1 Introduction
This manual contains information for the proper installation and operation
of the Audio International, Inc. (AI) Audio Amplifiers, Models # PA-475-A,
PA-475-B, and PA-475-C. Also included are physical and electrical
characteristics of the unit.
1.2 Purpose of the Equipment
The PA-475-A, PA-475-B, and PA-475-C are Class “D”stereo, audio
amplifiers that deliver high performance, excellent frequency response,
and clear sound quality. The units have small footprints and generate little
heat yet can produce dual output, high-power, high fidelity sound.
1.3 Operational Features
Listed below are key features of the PA-475-A, PA-475-B, and PA-475-C:
q Solid state circuitry
q Small footprint
q Minimal heat generation
q Dual output, high-power, high fidelity sound
q Automatic speaker turn ‘ON’and PA audio level setting when PA
interface is activated
q Lightweight, compact
q Specially designed to meet aircraft standards
1.4 Optional Equipment
Audio International, Inc. offers a complete line of speaker systems to
enhance any aircraft entertainment system. As an industry leader in
aviation entertainment systems, Audio International, Inc. can offer the
perfect combination for the quietest listening and the highest quality in
personal audio entertainment.
Contact your AI representative for details.

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 5 of 12
2.0 Application
2.1 Introduction
The PA-475-A, PA-475-B, and PA-475-C are audio amplifiers that will
produce stereo audio output for the entertainment system and monaural
audio for page / chime. Up to four (4) midrange / tweeter and four (4)
subwoofers can be connected to an amplifier.
Each amplifier is designed to interface with AI’s proprietary RS485 serial
data bus allowing all entertainment switch panels to communicate with the
audio amplifier.
The differences between the units is as follows:
½ The PA-475-A has the capability of producing four (4) channels,
75 watts RMS peak output, 150 maximum per channel output
power. Output impedance 4-ohms per channel. Electric
crossover low range 20 –135 Hz, high range 135 –20 kHz.
½ The PA-475-B has the capability of producing four (4) channels,
50 watts RMS peak output, 100 maximum per channel output
power. Output impedance 4-ohms per channel. Electric
crossover low range 20 –135 Hz, high range 135 –20 kHz.
½ The PA-475-C has the capability of producing four (4) channels,
50 watts RMS peak output, 100 maximum per channel output
power. Output impedance 4-ohms per channel. Electric
crossover low range 20 –300 Hz, high range 300 –2 kHz
2.2 Block Diagram –Typical Application

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 6 of 12
3.0 Installation
3.1 Prior to Installation
Prior to installation, the following items should be considered:
3.1.1 During the design and layout of the aircraft cabin, careful
consideration of the location of this module is necessary. Some of
the items to be considered include:
• Space
• Available power supply
• Environmental conditions (temperature, humidity, etc.)
• Length of cable runs
3.1.2 The PA-475-A (-B) (-C) shall be installed to conform to the
standards designated by the customer, installing agency, and
existing conditions as to the unit location and type of installation.
3.1.3 Mounting screws are required to secure the unit. Refer to Section
6.0, Reference Drawings, for mounting hole diameters and
configuration.
3.1.4 The purpose of the audio amplifier is to compensate for low level
audio signals and “amplify”them to a high level. The amplifier will
be most effective when the interior is thoroughly furnished and all
pieces of furniture are in place.
3.1.5 The unit generates minimal heat. Allow a minimum of ½inch air
space around the amplifier due to heat generation.
3.2 Unpacking and Inspection
Carefully open the packaging and remove the unit. Verify that all
components have been included in the package per the packing list.
Inspect the unit for damage. Retain the packing materials and packing
list.
If damage has occurred during shipping, a claim must be filed with AI
within 24 hours and a “Return Request Authorization Number”must be
obtained from AI. Refer to the front cover of this manual for address and
telephone number of Audio International. Repackage the unit in its
original packaging materials and return it to AI following instructions given
by the AI representative. If no return is necessary, retain the packing
materials for storage or reshipment if necessary.

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 7 of 12
3.3 Cautions and Warnings
3.3.1 It is important to do a pin-to-pin power and ground check on all
connectors. Ensure that power and ground are applied only where
specified. Damage to the unit may result if power or ground is
applied to the wrong points.
3.3.2 DO NOT connect or disconnect the module while power is applied.
3.3.3 DO NOT remove any factory-installed screws. Damage to the units
may result and void any warranties.
3.3.4 ESD (Electro Static Discharge) guidelines shall be followed.
3.4 Wiring Requirements
3.4.1 Introduction
The installing agency shall supply and fabricate all external cables
and mating connectors. The length and routing of external cables
must be carefully studied and planned before attempting installation
of the equipment. Allow adequate space for installation of cable
and connectors. Avoid sharp bends and placing cables near
aircraft control cables. Maintain a minimum clearance of three (3)
inches from any control cable. If wiring is run parallel to
combustible fluid or oxygen lines, maintain a separation of six (6)
inches between the lines.
3.4.2 Power Wires
All power and ground wires shall be 18 AWG (minimum). Power
ground wires shall be grounded within twelve (12) inches of the
unit. All wires shall be in accordance with MIL-W-22759 or
equivalent. Protect power wires with circuit breakers or fuses
located close to the electrical power source bus.
3.4.3 Input Cables
All input cables are 22 AWG (minimum) twisted shielded pair with
the cable shields properly grounded. Twisted shielded cable shall
be in accordance with MIL-W-27500 or equivalent.
3.4.4 Output Cables
All output cables are 20 AWG (minimum), 16 –18 AWG preferred.
Output cables require twisted, shielded pair with the cable shields
properly grounded. Twisted shielded cable shall be in accordance
with MIL-W-27500 or equivalent.

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 8 of 12
3.4.5 Data Bus Lines
All data bus connections require twisted shielded cable with the
cable shields properly grounded. Twisted shielded cable must be
in accordance with MIL-W-27500 or equivalent. The wire size for
the conductors in this cable is to be 22 AWG (minimum). The
shield is to be connected wherever a shield pin is provided. Shield
terminations are to be made as close to the connector pin as
possible. In the event shield pins are not provided, the data bus
shield must be terminated per AI’s proprietary RS485 specification.
All equipment on the RS485 data bus shall be connected in a
“daisy-chain”configuration. AI’s proprietary RS485 serial data bus
specification is available upon request.
3.5 Physical Characteristics
3.5.1 Refer to Section 5.0 for unit dimensions.
3.5.2 Refer to Section 6.0 for attachment points.
3.5.3 When mounting the unit, allow sufficient space for mating
connectors.
3.6 Electrical Characteristics
3.6.1 Refer to Section 5.0 for electrical specifications.
3.6.2 P1 is an 11-pin connector. The signals interfaced through P1 are
left / right speaker, +28 VDC emergency power and woofer outputs.
The emergency +28 VDC power input is required for cabin page
and chime functions in case of power failure.
3.6.3 P2 is a 15-pin connector. The signals interfaced through P2 are the
entertainment inputs of left / right audio input, PA/Chime, data ID,
and RS485 data bus.
The device ID pins are used to provide a unique address on the
RS485 data bus. These are binary ID pins and will allow up to four
modules to be installed on the aircraft RS485 data bus.
3.6.4 P3 is a 3-pin connector. The signal interfaced through P3 is 115
VAC power.

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 9 of 12
3.7 Mating Connector Information
All wiring harnesses to the unit are supplied and fabricated by the
installing agency.
Pin # Part Number Description
P1 MS3126F-18-11S Mating Connector
P2 RD15F10HVL0 Mating Connector
P3 MS3126F-10-6S Mating Connector
3.8 Pinout Assignment Descriptions
P1 P2
Pin # Description Pin # Description
A Left Speaker HI 1 Left Audio +
B Left Speaker LO 2 Left Audio -
C Right Speaker HI 3 Ground
D Right Speaker LO 4 Right Audio +
E Woofer 1 HI 5 Right Audio -
F Woofer 1 LO 6 Ground
G Woofer 2 HI 7 Ground
H Woofer 2 LO 8 Data ID (1)
J Emergency +28 VDC 9 Data ID (2)
K Ground 10 PA Audio +
L Ground 11 PA Audio -
12 Ground
13 PA Key Ground In
14 CMS Data Bus A
15 CMS Data Bus B
P3
Pin # Description
A 115V ACH 400 Hz
B 115V ACN 400 Hz
C Ground
D N/C
E N/C
F N/C

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 10 of 12
3.9 Post-Installation Test
With the aircraft power “ON”, test the audio amplifier. Any unit connected
to the RS485 data bus may be used to test proper operation of the unit.
While an entertainment audio unit is sending audio signals through the
amplifier, key and speak into a microphone to ensure that the page /
chime overrides the entertainment audio. Ensure all microphones are
tested. Verify that the briefer audio can be heard through the speakers.
Remove power from the amplifier and verify that the +28 VDC emergency
power is supplied to the amplifier. Verify that the subwoofers are disabled
while emergency power is applied. Ensure that PA audio can be heard in
the speaker system from all respective microphones.
4.0 Troubleshooting Guide
General Troubleshooting Procedures
Many problems can be isolated with the following general techniques:
• To verify power to the unit, recheck 115 VAC and +28 VDC is applied
to the proper pins on the unit. Use a voltmeter to verify correct level.
• Reset by removing power from the unit for at least one minute and
reapply power. Verify the problem still exists.
• Recheck all connections to the unit for security. Check all harness
runs for possible pinching. Recheck all pinouts for application
accuracy.
Should difficulties arise in the installation or operation of the unit, contact Audio
International, Inc. product support.

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 11 of 12
5.0 Specifications
Unit Specifications
Physical Specifications
Housing Aluminum
Dimensions
(L x W x H) 9.3”x 4.9”x 4.0” 23.6cm x 12.5cm x 10.2cm
Weight PA-475-A 5.1 lbs / 2.31 kg
PA-475-B (-C) 5.3 lbs / 2.40 kg
Electrical Specifications
Power 2.5 A nominal, 5A maximum @ 115 VAC
60-400Hz
Emergency Power +28 VDC Page / Chime
Data Bus Type AI Proprietary RS485
Electric Crossover /
Channel Output PA-475-A
PA-475-B
PA-475-C
Low Range: 20 –135 Hz
High Range: 135 –20 kHz
4-channel, 75 watts RMS peak
output, 150 maximum per channel
Low Range: 20 –135 Hz
High Range: 135 –20 kHz
4-channel, 50 watts RMS peak
output, 100 maximum per channel
Low Range: 20 –300 Hz
High Range: 300 –20 kHz
4-channel, 50 watts RMS peak
output, 100 maximum per channel
Output Impedance 4-ohms per channel

Audio International, Inc. PA-475-A(-B)(-C) Installation
Document #540021, Rev. C, 4/2000 Page 12 of 12
6.0 Reference Drawings
The following diagrams show the unit dimensions and connector locations for the
PA-475-A (-B) (-C). All dimensions are shown in inches.