Audio Precision APx555 User manual

APx555
audio analyzer
Installation Instructions
and Specifications
January, 2016
model APx555

Copyright © 2006–2016 Audio Precision, Inc.
All rights reserved.
Printed in the United States of America.
No part of this manual may be reproduced or transmitted
in any form or by any means, electronic or mechanical, in-
cluding photocopying, recording, or by any information
storage and retrieval system, without permission in writing
from the publisher.
AUDIOPRECISION,theAUDIOPRECISIONlogoandthe
AP logo are trademarks of Audio Precision and are regis-
tered in the U.S. Patent and Trademark Office and in other
countries. Windows™ is a trademark of Microsoft Corpora-
tion. Dolby and the double-D symbol are trademarks of
Dolby Laboratories, Inc. DTS is a trademark of DTS, Inc.
pn 8211.0335 rev 004 XVI0115111108
Audio Precision
5750 SW Arctic Drive
Beaverton, Oregon 97005
503-627-0832
800-231-7350
ap.com

Documentation and Support
This booklet contains safety information, installation instructions and full specifications
for theAudio Precision APx555 audio analyzer.
The APx500 User’s Manual
Detailed information on the operation of the APx555 is available from the embedded Help
installed with the APx500 measurement software, and in the APx500 User’s Manual, included
with the analyzer. The user’s manual is also available as a PDF on the APx500Application
Disc and on the Web at ap.com; additional copies can be ordered fromAudio Precision or
your local distributor.
Audio Test Discs
These discs are included with your analyzer system:
• APx-DVD1 is a playable video DVD with menu-driven linear and coded audio test sig-
nals for external source use with DVD players.
• APx-CD1 is a playable audio CD with linear audio test signals for external source use
with CD players.
ap.com
Visit the Audio Precision Web site at ap.com forAPx support information.APx resources
are available at ap.com/downloads/apx. You can also contact our Technical Support staff at
techsuppor[email protected], or by telephoning 503-627-0832 extension 4, or 800-231-7350 exten-
sion 4 (toll free in the U.S.A.).

APx555 Audio Analyzer: Table of Contents i
Table of Contents
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Abbreviations, Terms and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
APx555 analog I/O specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
ADIO specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
DSIO specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
HDMI+ARC specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Bluetooth specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
PDM specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
AMC specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
General and Environmental specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Chapter 1: Table of Contents
ii APx555 Audio Analyzer: Table of Contents

APx555 Audio Analyzer: Safety Information iii
Safety
Safety Information
Do NOT service or repair this equipment unless properly
qualified. Servicing should be performed only by a quali-
fied technician or an authorized Audio Precision distributor.
Do NOT defeat the safety ground connection. This equip-
ment is designed to operate only with an approved three-
conductor power cord and safety grounding. Loss of the
protective grounding connection can result in electrical
shock hazard from the accessible conductive surfaces of this
equipment.
Do NOT exceed mains voltage ratings. This equipment is
designed to operate only from a 50–60 Hz ac mains power
source at 100–240 Vac nominal voltage. The mains supply
voltage is not to exceed ±10 % of nominal (90–264 Vac).
For continued fire hazard protection, fuses should be
replaced ONLY with the exact value and type indicated on
the rear panel of the instrument and discussed on page 3 of
this manual.
The International Electrotechnical Commission
(IEC 1010-1) requires that measuring circuit terminals used
for voltage or current measurement be marked to indicate
their Measurement Category. The Measurement Category is
based on the amplitude of transient or impulse voltage that
can be expected from the AC power distribution network.
This product is classified as Measurement Category I,
abbreviated “CAT I” on the instrument front panel. This
product should not be used within Categories II, III, or IV.
The 2-channel input module measurement terminals are
rated for a maximum voltage of 230 Vpk to ground, and a
signal input of 160 Vrms unbalanced, 300 Vrms balanced;
the 8-channel input module measurement terminals are
1

Chapter 1: Safety
iv APx555 Audio Analyzer: Safety Information
rated for a maximum input of 160 Vpk to ground, and a sig-
nal input of 115 Vrms, balanced or unbalanced. These ter-
minals are intended to be used for the measurement of audio
signals only.
Do NOT substitute parts or make any modifications with-
out the written approval of Audio Precision. Doing so may
create safety hazards. Using this product in a manner not
specified by Audio Precision can result in a safety hazard.
This product is for indoor use—Installation Category II,
Measurement Category I, pollution degree 2.
Safety Symbols
The following symbols may be marked on the panels or
covers of equipment or modules, and are used in this man-
ual:
WARNING!—This symbol alerts you to a potentially haz-
ardous condition, such as the presence of dangerous volt-
age that could pose a risk of electrical shock. Refer to the
accompanying Warning Label or Tag, and exercise extreme
caution.
ATTENTION!—This symbol alerts you to important oper-
ating considerations or a potential operating condition that
could damage equipment. If you see this marked on equip-
ment, refer to the Operator’s Manual or User’s Manual for
precautionary instructions.
FUNCTIONAL EARTH TERMINAL—A terminal marked
with this symbol is electrically connected to a reference
point of a measuring circuit or output and is intended to be
earthed for any functional purpose other than safety.
PROTECTIVE EARTH TERMINAL—A terminal marked
with this symbol is bonded to conductive parts of the instru-
ment and is intended to be connected to an external protec-
tive earthing system.
Disclaimer
Audio Precision cautions against using their products in a
manner not specified by the manufacturer. To do otherwise
may void any warranties, damage equipment, or pose a
safety risk to personnel.

Chapter 1: Safety
APx555 Audio Analyzer: Safety Information v

APx555 Audio Analyzer: Installation

APx555 Audio Analyzer: Installation 1
2
Installation
Software
All APx systems use the same award-winning measure-
ment software, APx500.
PC system requirements
The APx500 measurement software version 4.1 and later
can be very demanding of the personal computer (PC) run-
ning the APx software.
Moderate measurement demands
Moderate measurement demands (measurement band-
widths under 90 kHz, channel counts of 2 or 1) will per-
form adequately using a PC with these minimum
specifications:
• Operating system: Microsoft Windows 8,Windows 7 or
Windows Vista.
• A multi-core processor (at least dual-core) running at a
clock speed of at least 2 GHz. Most current processors
from Intel and AMD meet these requirements.
Note: the Intel Atom processor does not meet our
minimum specification.
• At least 2 GB of RAM.
• At least 300 MB of free hard disk space.
• A CD-ROM optical disc drive.
• A USB 2.0 port; two are required for optional switcher
or DCX-127 use.
• A color monitor and a video card with at least VGA
capabilities. Video resolution of 1024 x 768 or greater
is recommended.

Chapter 2: Installation
2APx555 Audio Analyzer: Installation
High measurement demands
High measurement demands (measurement bandwidths
above 90 kHz, channel counts over 2) will perform much
better with a superior PC; in some cases, very high mea-
surement demands can slow or stop measurements.
The APx555, in particular, can place very high demands on
the PC system when used in high bandwidth testing.
Please view the current APx PC Minimum System Solu-
tions document on our Web site at www.ap.com/display/
file/764. This information will help you to determine the
adequacy of a particular PC for high-bandwidth, high-chan-
nel count measurement.
Installation
To install the measurement software, insert theAPx500 CD-
ROM into the optical drive on the PC and follow the
instructions in the installation dialog.
NOTE: You must have local administrator rights
to install APx500 software. Go to User Accounts
in the Windows Control Panel, or check with your
network administrator.
Running the software without instrument hard-
ware attached
You can launch the APx500 software without instrument
hardware attached. When no hardware is detected, APx500
will present you with the following dialog box:
Select “Demo Mode.”APx500 will run in demo mode,
which allows you to explore the user interface but does not
enable any measurement functions. Input data shown in
Demo Mode is false data, generated for display only.
From the Instrument Type menu, select an instrument to be
emulated in Demo Mode.
Running the software with instrument hardware
attached
NOTE: You must have standard user rights or
administrator rights to operate APx500 software.
Guest users are not supported.
Connecting the instrument to your PC
Before connecting your APx instrument to your PC, install
the APx500 measurement software as described above.
Connecting the instrument prior to software installation
may cause Windows to select an incorrect USB driver for
the instrument.
USB driver selection
The measurement software communicates with the instru-
ment using a USB 2.0 interconnection. Once the software is
successfully installed, connect one end of the USB cable to
a USB 2.0 port on the PC, and the other end to the PC
INTERFACE port on the rear of the instrument. We
strongly recommend that you use the USB cable included
with your instrument (AP order number CAB-APSI). We
have tested other USB cables that perform poorly.
Note: Some PCs have optional USB ports on the
front of the PC, or on extension brackets on the
rear. In many cases these convenience ports
have compromised performance due to the extra
cable length within the PC. We recommend using

Chapter 2: Installation
APx555 Audio Analyzer: Installation 3
USB ports directly connected to the PC mother-
board, typically at the rear of the PC.
Connect the instrument mains power cord to the instrument
and to a source of ac mains power. See Connecting your
instrument to the electrical mains supply below for more
information about mains connections.
Turn the instrument ON by pressing the pushbutton on the
front of the instrument. Microsoft Windows will detect the
presence of the instrument on the USB and will open the
Hardware Update Wizard to search for the correct software
driver. Select “Install the software automatically.” Win-
dows will find the Audio Precision driver software installed
with APx500 and connect to the instrument.
Launch APx500 by double-clicking on the installed short-
cut. With the instrument connected, you may be asked to
update the instrument firmware during the first launch of
the measurement software. APx500 will start, and in a short
time you will be presented with the opening screen. Refer to
the APx500 User’s Manual for more information about
making measurements.
A copy of the APx500 User’s Manual is included
with your instrument. The manual is also avail-
able as a PDF on the APx500 Application Disc
and online at ap.com.
Connecting your instrument to the electrical
mains supply
The APx500 series instrument must be connected to a 50–
60 Hz alternating current (ac) electrical mains supply. The
minimum voltage is 90 Vac; maximum voltage is 264 Vac.
The instrument is fitted with a universal power supply that
does not require voltage configuration or change of fuse
type to accept mains voltages within the specified range.
For all rated voltages, use two mains fuses of type 2A T/SB
(5 x20 mm) 250 V.
Removing and installing mains fuses
To remove the mains fuse carrier module, refer to the fig-
ures below and proceed as follows:
Power entry module Fuse carrier removal
Remove the mains power supply cord from the connector
on the power entry module, located on the instrument rear
panel. The mains fuse carrier module is part of the power
entry module, to the right of the power cord connector.
Insert a small screwdriver into the power cord connector
area, reaching into the slot on the mains fuse carrier mod-
ule. Pry the module out slightly, until you can grasp the
module firmly with your fingers. Pull the fuse carrier mod-
ule out of the power entry module. The two mains fuses are
loosely mounted within the fuse carrier module; take care
not to let them fall.
Replace the fuses if necessary, using fuses as described
below. Carefully reinsert the fuse carrier module into the
power entry module, and press it firmly into place.
Connect the power cord from a mains power outlet to the
power cord connector on the instrument rear panel.

Chapter 2: Installation
4APx555 Audio Analyzer: Installation

Abbreviations, Terms and Symbols 5
Abbreviations, Terms and Symbols
used in the following specifications
ADC or A/D . . . . . . . .Analog to Digital converter or conversion.
BW . . . . . . . . . . . . . . .Bandwidth or Measurement Bandwidth, nominally at –3 dB; a single number
indicates only the upper limit.
DAC or D/A . . . . . . . .Digital toAnalog converter or conversion.
DSP . . . . . . . . . . . . . . .Digital Signal Processing or Digital Signal Processor.
DUT . . . . . . . . . . . . . .Device Under Test, the device to which the generator or analyzer is connected.
EMC . . . . . . . . . . . . . .Electro-Magnetic Compatibility, usually refers to both emissions (radiated and
conducted viaAC mains) and susceptibility.
ENBW . . . . . . . . . . . . .Equivalent Noise Bandwidth,the frequency of an ideal filter having the same rms
response to white noise.
FFT . . . . . . . . . . . . . . .Fast Fourier Transform, a mathematical process converting a signal in the time
domain to the frequency domain.
IMD . . . . . . . . . . . . . . .Inter-Modulation Distortion, a measure of non-linearity using a test signal with
two or more components.
RMS or rms . . . . . . . . .Root Mean Square, an equivalent-power expression of signal amplitude.
SR . . . . . . . . . . . . . . . .Sample Rate, usually as it applies to the conversion rate ofA/D and D/Aconvert-
ers or digital audio formats.
THD . . . . . . . . . . . . . .Total Harmonic Distortion, rms summation of d2 to d9 (may be bandwidth lim-
ited), usually derived from an FFT.
THD+N . . . . . . . . . . . .Rms measurement ofALL harmonics, spurious signals, and noise within a speci-
fied bandwidth.
Typical or Typ . . . . . . .Acharacteristic that is not guaranteed, usually due to a practical limitation in
testing or metrology.
UI. . . . . . . . . . . . . . . . .Unit Interval, a measure of time is it applies to digital audio formats.
1 UI= 1/(128 • SR)
[ ] . . . . . . . . . . . . . . . . Indicates a specification in an equivalent unit, for example: 0.030 dB [0.35%] or
10.61 Vrms [30.00 Vpp].
≈. . . . . . . . . . . . . . . . .Indicates an approximate or nominal value, or range of values; not guaranteed.

6Abbreviations, Terms and Symbols

APx555 Audio Analyzer: Analog I/O Specifications 7
555
Analog I/O specifications
APx555 audio analyzer
with APx500 v4.2 or higher measurement software
October 2015 NP0020.00022 r002
This illustration shows an APx555 in its standard configuration, with an ADIO module installed.
These specifications cover the analog input and output functions of the Audio Precision
APx555.
Specifications for theADIO interface and other available interface modules including DSIO,
HDMI, PDM, Bluetooth and AMC, are found in other sections of this document, as are Gen-
eral and Environmental specifications for the entire APx family.
Analog specifications begin on the next page.

Characteristic Specifications Supplemental Information
8 APx555 Audio Analyzer: Analog I/O Specifications
555
ANALOG GENERATOR
Number of Channels 2, independent amplitude control
Waveforms Sine, sine split frequency, sine split
phase, sine+DC offset, continuously
swept-sine, square-wave, noise, IMD
signals, multi-tone, wave file playback
DC offset capability applies to all DAC
waveforms. Projects created with the Hi-
Perf Sine will load as Sine in other APx
analyzers.
High Performance Sine
Generation Technique Exceptionally stable RC oscillator
Frequency Range (Fs) 5 Hz to 204.75 kHz
Frequency Setting Resolution
5.0 Hz to 204.75 Hz 0.025 Hz
205.0 Hz to 2.0475 kHz 0.25 Hz
2.050 kHz to 20.475 kHz 2.5 Hz
20.50 kHz to 204.75 kHz 25 Hz
Frequency Accuracy
10 Hz to 100 kHz ±0.35% Typically <25 ppm/°C
5 Hz to 204 kHz ±0.5%
Amplitude Range 1
10 Hz to 100 kHz
0-26.66 Vrms [75.4 Vpp] bal;
0-13.33 Vrms [37.7 Vpp] unbal & CMT
Will drive 600 balanced load to at
least +30.0 dBm when Rs = 40 
5 Hz to 204 kHz
0-21.22 Vrms [60.0 Vpp] bal;
0-10.61 Vrms [30.0 Vpp] unbal & CMT
Amplitude Setting Resolution Typically <0.001 dB or 0.05 µVrms
Amplitude Accuracy, 1 kHz
+15°C to +30°C ±0.030 dB [±0.35%]
0°C to +45°C ±0.040 dB [±0.46%]
Flatness, 1 kHz ref
5 Hz to 20 kHz ±0.008 dB Typically <0.003 dB
20 kHz to 50 kHz ±0.015 dB
50 kHz to 100 kHz ±0.060 dB
100 kHz to 204 kHz ±0.15 dB
Settling Time Typically <(40 cycles + 100 ms) to within
0.001 dB of final value