EAW UXA4403 User manual

UXA4403
User Manual

Technical and Safety Notices
Please read the following important technical, safety
and environmental notices before installing and using
your amplier.
Technical Notices
All reasonable design and engineering steps have been taken
to ensure that these ampliers always perform satisfactorily
in their intended application and environment and will provide
appropriate levels of support to ensure that all reasonable
customer needs and expectations are met. Such support
however is contingent on the following provisions.
1. These ampliers are Class-I products and should be installed
with a mains cable including the required earth connection to
comply with the Safety Class-I.
2. These ampliers should always be installed by competent
and qualied personnel. Amplier damage or failure caused
by installation or operational errors may invalidate support,
warranty or guarantees of performance.
3. These ampliers are not suitable for use in locations where
they may be accessible to minors.
4. These ampliers are intended to be used specically for the
amplication of audio signals and for connection to moving-coil
loudspeaker systems. Use of these ampliers for amplication
of signals outside the audio band (20Hz to 20kHz) or to
drive transducers other than moving-coil loudspeakers may
invalidate support, warranty or guarantees of performance.
5. These ampliers should only be used within professionally
installed and congured audio systems comprising input
and output ancillary equipments that is known to be of an
appropriate level of performance and in good operating
condition. Any damage to, or unsatisfactory performance from,
these ampliers caused by inadequate or failed input or output
ancillaries may invalidate support, warranty or guarantees of
performance.
6. These ampliers are intended to be installed and operated
indoor in a controlled environment (pollution degree, PD2)
within an ambient temperature range of 0°C to 40°C. These
ampliers are not intended for use above 2000 meters above
sea level. Ampliers installed or operated in environments
outside these limits may invalidate support, warranty or
guarantees of performance.
7. Specic warranty terms are the responsibility of the amplier
re-seller.
Safety and Environmental Notices
Note: The intent of the lightning ash with arrowhead symbol
in a triangle is to alert the user to the presence of uninsulated
“dangerous” voltage within the product’s enclosure that may be of
sufcient magnitude to constitute a risk of electric shock to humans.
Note: The intent of the exclamation point within an equilateral
triangle is to alert the user to the presence of important safety, and
operating and maintenance instructions in this manual.
WARNING! TO PREVENT FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR
MOISTURE.
Ambient Temperature Note: If this equipment is
operated in a conned or multiple rack installation, the
internal ambient operating temperature may exceed
the external ambient temperature.
It is important to ensure in these
circumstances that the published
maximum operating temperature for the
equipment is not exceeded.
Reduced Air Flow: Ensure that rack or
other closed installation does not restrict
the cooling airow required for safe and
reliable operation of the equipment.

Technical and Safety Notices
Important Safety Instructions
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Do not submerge the equipment in water or liquids.
7. Do not use any aerosol spray, cleaner, disinfectant or
fumigant on, near or into the equipment.
8. Clean only with a dry cloth.
9. Do not block any ventilation opening. Install in accordance
with the manufacturer’s instructions.
10. Do not install near any heat sources such as radiators, heat
registers, stoves, or other apparatus (including ampliers)
that produce heat.
11. To reduce the risk of electrical shock, the power cord shall
be connected to a mains socket outlet with a protective
earthing connection.
12. Do not defeat the safety purpose of the polarized or
grounding type plug. A polarized plug has two blades with
one wider than the other. A grounding type plug has two
blades and a third grounding prong. The wide blade or the
third prong are provided for your safety. If the provided
plug does not t into your outlet, consult an electrician for
replacement of the obsolete outlet.
13. Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the
point where they exit from the apparatus.
14. Do not unplug the unit by pulling on the cord, use the plug.
15. Only use attachments/accessories specied by the
manufacturer.
16. Unplug this apparatus during lightning storms or when
unused for long periods of time.
17. Refer all servicing to qualied service personnel. Servicing
is required when the apparatus has been damaged in any
way, such as power supply cord or plug is damaged, liquid
has been spilled or objects have fallen into the apparatus,
the apparatus has been exposed to rain or moisture, does
not operate normally, or has been dropped.
18. The appliance coupler, or the AC Mains plug, is the AC
mains disconnect device and shall remain readily accessible
after installation.
19. Adhere to all applicable, local codes.
20. Consult a licensed, professional engineer when any
doubt or questions arise regarding a physical equipment
installation.
Environmental Statement
This product complies with international
directives, including but not limited to the
Restriction of Hazardous Substances (RoHS)
in electrical and electronic equipment, the
Registration, Evaluation, Authorization and
restriction of Chemicals (REACH) and the
disposal of Waste Electrical and Electronic Equipment (WEEE).
Consult your local waste disposal authority for guidance on
how properly to recycle or dispose of this product.

Introduction and Overview
1. Introduction
UXA4403 power ampliers have been designed to provide
congurable, consistent and reliable high performance
audio power amplication for residential, commercial and
entertainment applications.
This manual covers the features, installation and functions
of the UXA4403. Please read the manual fully before
installing and using an amplier. If you have any questions
regarding amplier conguration, installation or operation
please contact the appropriate customer support portal.
Following this introduction, the manual is divided into sections
covering the following topics:
• 2. Overview
• 3. Carton Contents
• 4. Installation
• 5. Conguration
• 6. Connections
• 7. Operation
• 8. Specications
2. Amplier Overview
UXA4403 ampliers are a full rack width, 2U format power
ampliers that can drive both conventional low impedance (Lo-Z,
4Ω to 16Ω) loudspeakers and high impedance (Hi-Z, 70V/100V)
transformer coupled loudspeakers. They provide four analog
inputs, one stereo S/PDIF digital input, and either two or four
outputs (Lo-Z mode), or one or two outputs (Hi-Z or Lo-Z BTL
mode). UXA4403 amplier model output channel counts and
power outputs are as follows:
[Mode Channels Max Rated Output per Channel
Lo-Z Four 750 Watts
Lo-Z (BTL) Two 1500 Watts
Hi-Z Two 1500 Watts
Note: In Lo-Z BTL (bridge-tied load) mode, two amplier output
channels are combined to create a single, double power output
channel. BTL mode can be engaged via the amplier Output
Mode conguration setup menu described in Section 5 of this
manual.

Introduction and Overview
2.1 Connections and Power Switching
UXA4403 signal input and output connections are accomplished
via RCA Phono and Euroblock style connectors. A GPIO (General
Purpose In/Out) Euroblock connector enables some amplier
functions to be controlled externally, and wireless or RJ45 socket
Ethernet network connection options are also provided. Cable
connectors and connections are described and illustrated in
Section 6 of this manual
UXA4403 ampliers incorporate a front panel mounted power
button. Press the button once to switch the amplier on or o.
Amplier power management behaviour can be congured via
the Control web app Settings Menu described in Section 5 of this
manual.
2.2 Network Features
UXA4403 ampliers are TCP/IP network connected devices that
require a wired or wireless network connection to access their
conguration menus. The conguration menus are accessed via
the Control Web App interface and cover Input, Zone, Output and
General Settings functions. The Control web app conguration
menus are described in Section 5 of this manual.
2.3 Firmware
This manual describes the features, functions and user interface of
UXA4403 ampliers running Firmware Version 1.2.0.
It is strongly recommended that the rmware version installed in
the amplier in use is checked initially, and regularly thereafter.
If updated rmware is available, the amplier should be
updated as a priority.
The rmware installed in the amplier can be identied and
updated by selecting the Device option in the Control web app
Settings Menu.
3. Carton Contents
UXA4403 ampliers are shipped in a cardboard carton containing
the amplier unit, a mains cable appropriate for the sales territory,
an accessory pack, and a document pack. The full contents is listed
below.
• Amplier unit
• Rack mount ears (tted)
• Mains power cable
• Input connector x 2
• GPIO socket connector
• Output connector x 1 or 2
• Adhesive rubber feet x 4
• Document pack

Installation
Diagram 1a
[AMP NAME] amplier dimensions.
(Shaded area denes ventilation space.)
440 mm
17.3 in
332 mm
13.1 in
4. Installation
4.1 Amplier Location
UXA4403 ampliers are shipped with rack“ears” attached and
are primarily intended for standard (19 inch)equipment rack
installation. If not to be installed in an equipment rack, UXA4403
ampliers can be placed free-standing on a at surface. Adhesive
rubber feet are supplied for this purpose.
It is important that any installation provides space for airow
through the ventilation apertures at the front and rear of the
amplier. This is illustrated in Diagram 1a.
88 mm
3.5 in

Conguration
5. Conguration
Before making input, output and GPIO connections,
an initial UXA4403 amplier conguration should
be established. It is particularly important that the
amplier output format is congured appropriately for
the speakers that are to be connected.
Conguration requires that UXA4403 ampliers are
connected to mains power and network services. These
connections are described in the following two sections.
5.1 Mains Power Connection
UXA4403 ampliers incorporate a power factor corrected power
supply and can be used with mains input voltage from 100V AC to
240V AC, 50/60Hz. Use the mains cable supplied with the amplier
and connect it to a switched mains supply.
UXA4403ampliers have no mains power switch and are
operational as soon as mains power is connected.
5.2 Network Services
UXA4403 ampliers are congured via a web page
interface. Before the conguration menus can be
accessed, UXA4403 ampliers must be connected to the
same TCP/IP network as the computer or mobile device
that is to be used for conguration access.
5.2.1 Wired (Ethernet) Network Connection
To connect a UXA4403 amplier to a TCP/IP network using a wired
connection (Ethernet) follow the steps below.
1. Use an Ethernet cable to connect the UXA4403 amplier rear
panel Network Control socket to a free socket on a network router
or switch, or directly to an Ethernet equipped laptop or desktop
computer.
2. Connect the UXA4403 amplier to mains power using the
supplied mains cable. Wait for the front panel Network indicator
to illuminate green to indicate that the amplier has network
connectivity.
3. The UXA4403 amplier default LAN IP address is 192.168.64.100.
Congure the laptop or desktop computer for a xed IP address
in the same IP range; eg. 192.168.64.10, with Subnet mask of
255.255.255.0 (or prex 24) and set the Gateway to 192.168.64.1.
4. Open a laptop or desktop web browser and enter the address
http://192.168.64.100. The UXA4403 Control Web App interface
will open to enable amplier conguration as required.
Note: UXA4403 ampliers can be congured to use DHCP for network
connection if required. However, if a UXA4403 amplier using DHCP is
power cycled, it is possible that the TCP/IP network router will assign
it a dierent IP address, leaving its conguration page inaccessible via
the previous address. If this occurs, a network scanning app can be
used to identify the new IP address. DHCP and Fixed IP address option
settings can be found in the Settings Tab menu described in Section
5.3.
5.2.2 Wireless (WiFi) Network Connection
To connect a UXA4403 amplier to a TCP/IP network using a
wireless connection (WiFi) follow the steps below.
1. With the UXA4403 amplier connected to mains power, wait for
the front panel WiFi indicator to illuminate green.
2. Use a mobile, laptop or desktop device to search for available
WiFi networks. Connect to, UXA4403 (product serial number)’
using the password, ‘password’. The amplier serial number can
be found on its rear panel.
3. Open a computer or mobile device web browser and enter the
IP address: 192.168.4.1. The UXA4403 Control Web App interface
will open to enable amplier conguration as required.
4. Select the Web App Settings Tab followed by WiFi > WiFi Mode
> Client to congure the amplier to connect to the required WiFI
network. The WiFi network name and password will be required.
It is strongly recommended that the UXA4403 amplier
Access Point WiFi password is changed following initial
wireless connection.

Conguration
5.3.1 Input Tab
The Input Tab provides naming, mono/stereo selection,
sensitivity, and gain trim for each amplier input channel. An
internal pink noise source, provided for system testing and set up,
can also enabled or disabled, and adjusted for gain via the Input
Tab. Diagram 4b illustrates the Input Tab.
Diagram 4a
Conguration Dashboard display
(two output amplier model shown)
Diagram 4b
Input Tab display
(two inputs only shown)
Note: When adjusting input gain, the input level display should
remain green. If it displays red, the input gain should be reduced.
5.3 Conguration Menus
Opening a web browser that is network connected to a UXA4403
amplier initially displays the UXA4403 Control Web App
Dashboard illustrated in Diagram 4a. The Dashboard is the ‘home’
page from which all other conguration options can be accessed.
The Dashboard displays the amplier status, output zones and the
conguration menu tabs. It also enables immediate access to zone
volume control The functions available under each conguration
menu tab are described in the following sections.

Conguration
5.3.2 Zone Tab
The Zone Tab enables installation zones to be dened and
named, and provides access to further sub-menus. Zones might
be bar or restaurant areas for example, or dierent rooms in
a home. For all Zone Tab menus, the installation zone under
conguration is selected by highlighting one of the zone
identiers (A, B, C or D) at the top of the page. Diagram 4c
illustrates the Zone Tab.
• The Source menu option enables inputs to be assigned to
zones.
• The GPIO Volume Control (Diagram 4d) option enables
external volume control to be applied to individual zones. The
GPIO conguration menu can be found under the Settings
Tab.
• The Compressor (Diagram 4e) option enables default or
custom signal compression to be applied to individual
installation zones.
Note:: Compression can be useful to reduce the volume dierence
between loud and quiet audio material. The lower the compression
threshold is set, the more the dierence between loud and soft will be
reduced. The overall zone volume may need to be increased
Diagram 4c
Zone Tab display
Diagram 4e
Zone Tab display
Diagram 4d
Zone Tab display

Conguration
5.3.3 Output Tab
The Output Tab enables amplier outputs to be named and
provides access to further sub-menus. For all Output Tab
menus, the amplier output under conguration is selected by
highlighting one of the output identiers (1, 2, 3 or 4) at the top
of the display. The Output Tab also enables Speaker Preset
congurations to be created, exported, imported or cleared.
Note:: The number of individual outputs available for conguration
will depend on the UXA4403 amplier model and the input, zone and
output mode conguration.
• The Routing menu (Diagram 4f) enables zones to be assigned
to amplier outputs.
Note: Routing for zones specied as stereo will automatically oer
three output options: left channel, right channel or summed mono.
The summed mono signal can potentially be used to drive a mono
subwoofer.
• The Delay menu (Diagram 4g) enables delay to be applied to
individual amplier outputs.
• The Equalizer menu (Diagram 4h) enables parametric
equalization to be applied to individual amplier outputs.
Equalizer settings congured for one amplier output can be
copied and applied to other outputs.
Diagram 4f
Diagram 4g
Diagram 4h

Conguration
• The Speaker Preset menu enables a set of speaker
parameters to be adjusted, and preset congurations to be
created.
• Speaker Presets can be simply applied to the selected
amplier output or imported, chosen from a library, exported
or cleared. The preset congurations can include any or all of
the parameters described in Section 5.3.4 and can be locked
to prevent inadvertent modication. Diagrams 4i to 4k
illustrate the application of speaker presets.
Speaker Preset data provided by third parties for use with
specic speakers can be imported and applied to amplier
outputs. To import speaker preset parameters follow the steps
described below and illustrated in the diagrams.
1. Select either the IMPORT PRESET FROM FILE or
SELECT PRESET FROM LIBRARY option from the
Speaker Preset menu. If no import option is visible,
select CLEAR to delete any existing speaker preset
data.
Note: The SELECT PRESET FROM LIBRARY option will be unavailable if
no speaker preset libraries have been created. Speaker preset library
creation and management is described in Section 5.3.5.
2. Select the appropriate ‘.zcp’format speaker preset
data le to import from either a Library or a computer
folder. The preset data will be applied to the selected
amplier output as soon as the le import is complete.
3. If the Speaker Preset data requires modication it can
be customized by selecting the CUSTOMIZE PRESET
option.
Note: If an imported Speaker Preset data le includes locked
parameters, they will be unavailable for modication.
5.3.4 Speaker Preset Menu Parameters
• The Crossover & Gain preset menu enables high or low-
pass crossover lters and gain adjustment to be applied to
individual amplier outputs.
• The Speaker EQ preset menu enables parametric equalization
to be applied to individual amplier outputs.
• The FIR preset menu enables FIR (Finite Impulse Response)
based equalization lter coecients generated by external
speaker measurement software to be imported and applied to
individual amplier outputs.
Note: FIR coecient les in either .csv or .txt format can be imported.
• The Driver Alignment preset menu enables delay to be
applied to individual amplier outputs.
Diagram 4i
Speaker Preset Parameters
Diagram 4j
Speaker Preset import le selection

Conguration
Diagram 4k
Speaker Preset applied
• The Crossover & Gain in the preset menu allows for
conguring a Low Pass and High Pass Filter, as well as
adjusting global gain (Diagram 4l).
Diagram 4l
Preset Crossover & Gain
• The Speaker EQ in the preset menu allows for conguring
customized parametric EQ on the output level. (Diagram 4m).
Diagram 4m
Preset Speaker EQ
• FIR in the preset menu provides a way to load a le with
determined FIR lters and parameters (Diagram 4n).
Diagram 4n
Preset FIR

Conguration
• The Output Mode preset menu enables individual amplier
outputs to be switched o or congured for Lo-Z or Hi-Z
modes. In Hi-Z modes, a high-pass lter can also be congured
and applied to the output. The number of outputs available
will depend on the amplier model, input setup and zone
setup. For example, a two output amplier will have two
outputs available if Lo-Z mode is selected but only one output
available if Hi-Z mode is selected (Diagram 4r).
Note:: Use of a high-pass lter with Hi-Z mode loudspeakers is useful
to avoid the possibility of distortion caused by low frequency line
transformer saturation. Begin with the default lter setting of 70Hz. If
low frequency distortion is still audible, increase the frequency setting
one step at a time until the distortion is no longer audible.
• Driver Alignment in the preset menu will allow for delay to
be set between driver passbands (Diagram 4o).
Diagram 4o
Preset Driver Alignment
• The Polarity preset menu enables the polarity of individual
amplier outputs to be reversed (Diagram 4p).
Diagram 4p
Preset Polarity
• The Limiter preset menu enables signal limiting to be
applied to individual amplier outputs. Clip limiting, peak
limiting and RMS limiting can be individually or collectively
engaged. The Peak limiter can be set to either automatic
or custom parameter values. The RMS limiter has default
parameter values that can be adjusted but has no automatic
option (Diagram 4q).
Note: In automatic mode, the peak limiter parameters adjust
automatically in response to Crossover & Gain high-pass lter
settings.
Diagram 4q
Preset Limiter
Diagram 4r
Preset Limiter

Conguration
Diagram 4s
Settings Tab menu
Diagram 4t
Speaker Library Creation and Management
Library name - type to edit
Library version - type to edit
Import preset data (.zcp) to library
Creat new library
Rename library
Edit or delete library
5.3.5 Settings Tab
The Settings Tab enables miscellaneous amplier settings to be
congured and installation data to be recorded. The Settings Tab
provides access to further sub-menus. Diagram 4s illustrates the
Settings Tab.
• The System Information menu provides text elds for the
recording of installation data.
• The Device menu records amplier specic information
such as the model number and rmware version. A rmware
update routine and identier button can also be found under
the Device menu.
• The Backup & Restore menu enables amplier conguration
data to be downloaded to an external archive, and enables
previously saved conguration les to be uploaded and
adopted by the currently connected amplier.
• The Speaker Library menu enables management of speaker
preset libraries. Existing libraries of speaker preset les (.zcl)
can be created or imported, and existing libraries edited
or fully deleted. Diagram 4t illustrates the creation and
management of speaker preset libraries.
• The Power Management menu enables various automatic
switch-on options to be engaged. The Power Management
menu also oers timed Standby and Mute functions.
• The GPIO menu enables conguration of the multi-purpose
GPIO interface pins.
• The LAN menu enables conguration and reset of the wired
network options and parameters.
• The WiFi menu enables conguration and reset of the wireless
network options and parameters.

Conguration
Diagram 4u
Signal Flow Schematic
(four output amplier)
Analog 3
Output
Matrix
Zones A - D
Outputs 1 - 4
Analog 2
Input
Sensitivity
Analog 1
Input
Gain
Input
Sensitivity
Input
Gain
Input
Sensitivity
Input
Gain
Analog 4
SPDIF (stereo)
SPDIF Out (stereo). Zones A (left) and B (right)
Pink Noise Gain
Delay
Level
Adjustment
Level
Adjustment
Level
Adjustment
Level
Adjustment
Compressor Compressor Compressor Compressor
Delay Delay Delay
EQ EQ EQ EQ
EQ EQ EQ EQ
FIR FIR FIR FIR
Polarity Polarity Polarity Polarity
Limiter
BTL
Amplifier
2 x Low-Z
1 x Hi-Z
BTL
Amplifier
2 x Low-Z
1 x Hi-Z
Limiter Limiter Limiter
Driver
Alignment
Driver
Alignment
Driver
Alignment
Driver
Alignment
Crossover Crossover Crossover Crossover
Gain Trim Gain Trim Gain Trim Gain Trim
Input
Sensitivity
Input
Gain
Input
Gain
Input
Selection
Input Setup
Zone Setup & Routing
Output Setup
Output 1 Output 2 Output 3 Output 4
Zone Adjustment Parameters Speaker Preset Parameters
5.4 Setup and Signal Routing
Thanks to their network based conguration features, UXA4403
ampliers oer considerable versatility in terms of sources, signal
routing, installation zones and output modes. Inputs can be freely
assigned to installation zones, and those zones assigned freely to
the availabl e amplier outputs in either Lo-Z or Hi-Z modes.
This versatility enables, for example, one amplier simultaneously
to drive both Lo-Z and Hi-Z speakers, or for dierent inputs to be
routed to dierent output zones.
The following paragraphs describe and illustrate the
recommended procedure for conguring input, zone and output
routing. A general signal ow schematic is also illustrated in
Diagram 4u.
5.4.1 Input Setup

Conguration
Open the conguration Dashboard and select the Input Tab. The
Input Tab is shown in Diagram 4b.
• To edit default input names simply select and type in the Input
Name eld.
• Dene a mono or stereo input by selecting the appropriate
option. Dening a stereo input will reduce the total number of
discrete inputs available.
• Select an input sensitivity option from the drop-down menu:
+14dB, +4dB, -10dB and‘microphone’ options are available.
Generally, the +14dB or +4dB options are appropriate for
‘professional audio’source hardware with balanced outputs,
while the -10dB option is more appropriate for ‘consumer
audio’ source hardware with unbalanced outputs. The
‘microphone’ option provides the signicantly greater
sensitivity required for microphones.
Note:: Only dynamic microphones are suitable for connection.
Phantom power for condenser microphones is not provided.
• If necessary, adjust the input gain using the slider or up/down
icons. Gain adjustment is intended to be used for ne output
level adjustment following initial use.
5.4.2 Zone Setup & Routing
Open the conguration Dashboard and select the Zone Tab. The
Zone Tab is shown in Diagram 4c.
• Select the zone to be congured. The number of zones
available and their channel format (stereo or mono) will
depend on the amplier model, input setup and output mode
(Lo-Z or Hi-Z). For example, a two output amplier can have
the following zone congurations:
• 1 x stereo Lo-Z zone
• 2 x mono Lo-Z zones
• 1 x mono Hi-Z zone
• A four output amplier can have the following zones
congured:
• 2 x stereo Lo-Z zones
• 4 x mono Lo-Z zones
• 2 x mono Hi-Z zone
• 1 x mono Hi-Z zone + 1 x stereo Lo-Z zone
• 1 x mono Hi-Z zone + 2 x mono Lo-Z zones
Note: When congured in Hi-Z mode UXA4403 ampliers operate in
‘bridged’ mode where the output of two channels is combined. This
means that the number of output channels available in Hi-Z mode is
half that available in Lo-Z mode .
Note: Mono signals might be mono at source, created though
combining the left and right channels of a stereo signal (summed
mono) or treating the left and right channels of a stereo signal
independently (split mono).
• Name zones by typing in the Zone Name eld.
• Adjust the zone volume if required by using the slider.
• Dene a mono or stereo zone by selecting the appropriate
option. Dening a stereo zone will reduce the total number of
further zones available.
• Specify an input for the zone by selecting from the drop-
down menu. Selecting a stereo input for a mono zone will
automatically sum the stereo channels to mono.

Conguration
5.5 GPIO Setup and Connection
UXA4403 ampliers provide a GPIO socket that enables
remote control of volume, standby, mute and trigger functions.
The GPIO connector pin functions are described in the GPIO
Settings menu illustrated in Diagram 4v. The connection of
GPIO based remote volume control and standby/mute are
illustrated in Diagram 4w and Diagram 4y respectively.
Note: The GPIO connector must not be used for any unintended
purpose. Amplier damage may result from incorrect use of
GPIO.
Note: Shielded cable must be used when connecting standby
switches and potentiometers via GPIO.
Note: GPIO Pin 8 has a low output impedance and is able to
supply a maximum current of 10mA.
Note: GPIO Pin 1 and Pin 3 both offer ground connections:
Pin 1 is connected directly to the amplier chassis.
Pin 3 is connected to the chassis via a 220 Ohm resistor.
The ‘soft ground’ connection of Pin 3 is potentially useful for
managing ground loops that may cause audible hum.
Diagram 4v
GPIO Settings Menu
Diagram 4w
Potentiometer connections for remote vol-
ume control via GPIO.
Note: Diagram 6c illustrates
use of the GPIO connector.
Diagram 4y
Connections for remote
standby/mute switch via GPIO.
Note: Diagram 6c illustrates
use of the GPIO connector.
Ground
+3V3
Ground
Standby/Mute
Potentiometer
(>10kΩ)
Connect Wiper to
Pin 4, 5, 6 or 7. Switch open or closed
toggles Standby or Mute
depending on options
selected in the GPIO
Settings Menu

Connections
6. Connections
UXA4403 amplier rear panel connections are
illustrated in Diagrams 5a.
6.1 Mains Power Connection
UXA4403 ampliers incorporate a power factor corrected
universal power supply and can be used with mains input
voltage from 100V AC to 240V AC, 50/60Hz. Use the mains
cable supplied with the amplier.
UXA4403 ampliers have no mains power switch and are
operational as soon as mains power is connected. Ensure that
all signal, GPIO and output connections are made before
connecting the amplier to mains power.
6.2 Input Connection
All UXA4403 amplier models provide four balanced or
unbalanced analog audio inputs and a stereo S/PDIF digital
audio input. Any input channel can be routed to any output
channel. Input routing options can be congured via the
amplier network interface. See Section 5 of this manual.
Analog Inputs
UXA4403 analog inputs are of line level format with a default
input sensitivity of +4dBu (full output voltage swing/sensitivity)
in all output modes. Input signal levels up to +24dBu can be
handled without input clipping. Input sensitivity options can
be set via the amplier network interface. See Section 5 of this
manual.
Balanced input connections to the ampliers are made via male
‘Euro Block’ connectors. Connecting cables to the supplied
female input connectors is illustrated in Diagram 5b.
Unbalanced input connections to the ampliers are made via
RCA phono sockets connected in parallel with the balanced
inputs.
Diagram 5a
UXA4403rear panel connections.
Note: Two output amplier model connection sockets differ only in
the deletion of channel 3 and channel 4 output connectors.
Digital Inputs
UXA4403 amplier S/PDIF stereo digital audio input
connections are made via a single RCA Phono socket. The S/
PDIF input is connected by default to amplier installation
Zones A (left) and B (right).
Digital Outputs
UXA4403 amplier S/PDIF stereo digital audio output
connections are made via a single RCA Phono socket. The S/
PDIF output signal by default reects the input to amplier
installation Zones A and B and is intended to be used for daisy-
chaining UXA4403 amplier.
Note: 75Ω RCA Phono cables specically intended for digital audio
should always be used for S/PDIF connections. Standard Phono
cables can be used but may not result in optimal performance.
Note: The S/PDIF output level is by default set at -10dB to reduce
the possibility of downstream input clipping.
6.3 Output Connections
Output connections from the ampliers are achieved via male
‘Euro Block’ connectors. Ensure that speaker connection
polarity is correct throughout the installation:
In the case of Lo-Z speaker connections, positive (+) amplier
terminals should always be connected to positive speaker
terminals and negative (–) amplier terminals always connected
to negative speaker terminals.
In the case of Hi-Z speaker connections, the two speaker cable
conductors should be connected between the positive (+)
terminal of Output 1 and the negative terminal (-) of Output 2,
and likewise for Outputs 3 and 4.
Output mode options (Lo-Z or Hi-Z) can be congured via the
amplier network interface. See Section 5 of this manual.
Connecting cables to the supplied female output connector is
illustrated in Diagram 5c.

Connections
6.5 Speaker Cable Gauge
UXA4403 speaker connection cable gauge should be
chosen appropriately to reect the type of installation.
The adjacent tables specify the appropriate cable gauge
for less than 0.5dB cable loss with different installation
types and cable lengths.
6.5 GPIO Connections
If any UXA4403 GPIO functionality is required, cables will
need to be connected to the supplied GPIO connector.
Connecting cables to the GPIO connector is illustrated in
Diagrams 5d.
6.6 Network Connections
UXA4403 ampliers are TCP/IP network connected
devices that are congured via a web page based
interface. Wired (Ethernet) and wireless (WiFi)
connection options are available. Connecting UXA4403
ampliers to a TCP/IP network is described in Section 5
of this manual
Cable Gauge Table
Lo-Z installations, 0.5dB attenuation. 4 Ω & 8 Ω loads
Cable Gauge Table
70V Hi-Z installations, 1.0dB attenuation
20 speakers evenly distributed
Cable Gauge Table
100V Hi-Z installations, 1.0dB attenuation
20 speakers evenly distributed
Cable Cross
Section
(mm2)
Cable Gauge
(AWG)
Max Cable
Length
(Metres, 4 Ω
load)
Max Cable
Length
(Metres, 8 Ω
load)
0.75 ≈18 5 10
1.5 ≈16 10 20
2.5 ≈14 17 35
4.0 ≈12 28 55
Cable Cross
Section
(mm2)
Cable Gauge
(AWG)
Max Cable Length
(Metres),
(125 W/channel)
Max Cable Length
(Metres),
(250 W/channel)
0.75 ≈18 90 45
1.5 ≈16 180 90
2.0 ≈14 <250 150
3.5 ≈12 <250 <250
Cable Cross
Section
(mm2)
Cable Gauge
(AWG)
Max Cable Length
(Metres),
(125 W/channel)
Max Cable Length
(Metres),
(250 W/channel)
0.75 ≈18 190 90
1.5 ≈16 <250 180
2.0 ≈14 <250 <250
3.5 ≈12 <250 <250
Note: Cable lengths should not exceed 250m.
Note: Cable lengths should not exceed 250m.

5 mm
Connections
Diagram 5b
Balanced analog input
cable connections.
Diagram 5c
Output cable connections.
Low-Z Mode
Hi-Z/BTL
Modes
5 mm
5 mm