XTA ULTRAFIDE U500DC User manual

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www.ultradeaudio.co.uk
U500DC
Ultra Fidelity Audiophile
Power Amplier.
Operators Manual

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Thank you for choosing an ULTRAFIDE/MC² product for
your application, it really is appreciated.
Please spend a little time reading through this manual,
so that you obtain the best possible performance
from the unit and become familiar with its operating
requirements.
All ULTRAFIDE/MC² products are carefully designed and
engineered for world-class performance and reliability.
If you would like further information about this or any
other product, please contact us:
hello@ultra deaudio.co.uk
We wish you many years of enjoyment from your new
ampli er and look forward to hearing from you in the
near future.
Scan the QR code or visit our website
www.ultra deaudio.co.uk to  nd out
more about us.
www.ultra deaudio.co.uk

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Contents
Declaration of Conformity .............................................................................................. 4
Introduction ..................................................................................................................... 5
Safety............................................................................................................................... 6
Installing .......................................................................................................................... 7
Basic Connections Set-up | AC mains power................................................................ 8
XLR/RCA connectors...................................................................................................... 9
Binding posts | Cable types required ...........................................................................10
Front and rear diagram .................................................................................................11
Other controls | Internal gain | Internal mains calibration ..........................................12
Operation and maintenance.........................................................................................13
Warranty information....................................................................................................13
Technical Specications...............................................................................................14
Quick start guide...........................................................................................................15

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DECLARATION OF CONFORMITY
We, the manufacturer:
XTA Electronics Ltd
(TRADING AS MC2 Audio, Ultrafide)
Units 6-7 Kingsgate
Heathpark Industrial Estate
Honiton, Devon
England
EX14 1YG
acknowledge our responsibility and self-certify the following products:
Kind of equipment: Audio amplifier
Commodity Code: 8518400090
Type Designation: U500DC
and all OEM/variants of this model
are manufactured in accordance with EMC Directive 2014/30/EU (CE and UKCA), in compliance with the
following norm(s) or document(s):
Technical Regulations: EN55032:2015 (Emissions)
EN55032:2017 (Immunity)
and in accordance with the: Low Voltage Directive 2014/35/EU (CE and UKCA)
in compliance with the following norm(s) or document(s):
Technical Regulations: EN/IEC62368-1:2020 (Audio, Video & Communication Safety)
and in accordance with the Directive 2011/65/EU on the restricted use of certain Hazardous
Substances in Electrical and Electronic Equipment (RoHS2). We certify that the above-mentioned products are
deemed compliant according to the details given in the directive.
Signed:
Name: Alex Cooper
Position: Research and Development Manager
Date: May 2022

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DECLARATION OF CONFORMITY
We, the manufacturer:
XTA Electronics Ltd
(TRADING AS MC2 Audio, Ultrafide)
Units 6-7 Kingsgate
Heathpark Industrial Estate
Honiton, Devon
England
EX14 1YG
acknowledge our responsibility and self-certify the following products:
Kind of equipment: Audio amplifier
Commodity Code: 8518400090
Type Designation: U500DC
and all OEM/variants of this model
are manufactured in accordance with EMC Directive 2014/30/EU (CE and UKCA), in compliance with the
following norm(s) or document(s):
Technical Regulations: EN55032:2015 (Emissions)
EN55032:2017 (Immunity)
and in accordance with the: Low Voltage Directive 2014/35/EU (CE and UKCA)
in compliance with the following norm(s) or document(s):
Technical Regulations: EN/IEC62368-1:2020 (Audio, Video & Communication Safety)
and in accordance with the Directive 2011/65/EU on the restricted use of certain Hazardous
Substances in Electrical and Electronic Equipment (RoHS2). We certify that the above-mentioned products are
deemed compliant according to the details given in the directive.
Signed:
Name: Alex Cooper
Position: Research and Development Manager
Date: May 2022
Introduction
The Ultrade U500DC is a high-end
dual channel power amplier with two
integral power supplies and single mains
connection, it is suitable for the most
discerning stereo Hi Fi, or can be used in
multiples for bi-amplied stereo or home
theatre applications.
Designed from the ground up for the most
demanding home listening environments
the U500DC eciently provides crystal
clear dynamic response with what feels
like endless power, grace, and ease.
The U500DC utilises two of our very
latest high speed push pull output stage
(“Sigma”) ampliers combined with
separate dual power supplies fed from
the mains via a single gold plated 10
Amp connection and a massive bespoke
shielded toroidal transformer that
provides total safety isolation.
The amplier provides dual binding posts
for each output allowing independent
wiring for tweeters and woofers plus dual
inputs; unbalanced RCA and balanced
XLR.

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IMPORTANT SAFETY INSTRUCTIONS
WARNING: Apparatus with CLASS I construction shall be connected to a MAINS socket outlet with a protective earthing connection.
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) Clean only with a dry cloth.
7) Do not block any ventilation openings, install in accordance with the manufacturer’s instructions.
8) Do not install near any heat sources, such as radiators, heat registers, stoves or other apparatus that produce heat.
9) Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles and the point where they exit from the apparatus.
10) The mains circuit breaker shall remain readily accessible.
11) Only use attachments/accessories specified by the manufacturer.
12) Use only with the cart, tripod, bracket or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus
combination to avoid injury from a tip over.
13) Disconnect this apparatus during lightning storms or when unused for a long period of time.
14) Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as if the 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.
15) Do not expose this equipment to dripping or splashing and ensure that no objects filled with liquids, such as vases, are placed on the equipment.
16) To completely disconnect this equipment from the AC mains, disconnect the power cord from the mains circuit breaker.
17) Where the amplifier is mounted in a rack and permanently connected to the mains, then the rack should be installed with a readily accessible connector or an ALL POLE
circuit breaker with 3mm breaking distances.
18) This unit is fitted with a C13 Mains IEC inlet. For safety reasons, THE EARTH LEAD SHOULD NOT BE DISCONNECTED IN ANY CIRCUMSTANCE.
INSTRUCTIONS DE SECURITE IMPORTANTES
1) Lisez ces instructions.
2) Conservez ces instructions.
3) Tenez compte de tous les avertissements.
4) Suivez toutes les instructions.
5) N'utilisez pas cet appareil près de l'eau.
6) Nettoyez uniquement avec un chiffon sec.
7) Ne pas bloquer les ouvertures de ventilation, installer conformément aux instructions du fabricant.
8) Ne pas installer à proximité de sources de chaleur telles que radiateurs, registres de chaleur, poêles ou autres appareils produisant de la chaleur.
9) Protégez le cordon d'alimentation contre les piétinements ou les pincements, en particulier au niveau des fiches, des prises de courant et du point de sortie de l'appareil.
10) Le disjoncteur secteur doit rester facilement accessible.
11) N'utilisez que les fixations/accessoires spécifiés par le fabricant.
12) Utiliser uniquement avec le chariot, le trépied, le support ou la table spécifié par le fabricant ou vendu avec l'appareil. Lorsqu'un chariot est utilisé, faire preuve de prudence
lors du déplacement de la combinaison chariot/appareil pour éviter les blessures en cas de renversement.
13) Débranchez cet appareil pendant les orages ou lorsqu'il n'est pas utilisé pendant une longue période.
14) Confiez tous les entretiens à un personnel de service qualifié. Une réparation est nécessaire lorsque l'appareil a été endommagé de quelque manière que ce soit, par exemple
si le cordon d'alimentation ou la fiche est endommagé, si du liquide a été renversé ou si des objets sont tombés dans l'appareil, si l'appareil a été exposé à la pluie ou à l'humidité,
ne fonctionner normalement ou a été échappé.
15) N'exposez pas cet équipement aux gouttes ou aux éclaboussures et assurez-vous qu'aucun objet rempli de liquide, tel que des vases, n'est placé sur l'équipement.
16) Pour déconnecter complètement cet équipement du secteur, débranchez le cordon d'alimentation du disjoncteur du secteur.
17) Lorsque l'amplificateur est monté dans un rack et connecté en permanence au secteur, le rack doit être installé avec un connecteur facilement accessible ou un disjoncteur
ALL POLE avec des distances de coupure de 3 mm.
18) Cet appareil est équipé d'une entrée secteur IEC C13. Pour des raisons de sécurité, LE FIL DE TERRE NE DOIT EN AUCUN CAS ÊTRE DÉBRANCHE.
CAUTION: RISK OF ELECTRIC SHOCK.
DO NOT OPEN
The lightning f
lash with arrowhead
symbol within an equilateral triangle is
intended to alert the user to the presence
if uninsulated dangerous voltagewithin
the products enclosure that may be of
sufficient magnitude to constitute a risk
of electric shock to persons.
The exclamation point within an
equilateral triangle is intended to alert
the user of important operating and
maintenance (servicing) instructions in
the literature accompanying the
appliance.
ATTENTION: RISQUE DE CHOC ELECTRIQUE.
NE PAS OUVRIR
ATTENTION: Appareils de construction de CLASSE I doit être raccordé au réseau électrique via une prise de courant
reliée à la terre.
ATTENTION: Pour éviter toute blessure, cet appareil doit être solidement fixé à la torture, conformément aux
instructions d'installation.
Le symbole repr
é
sentant un éclair fl
é
ch
é
dans un tr iangle équilatéral a pour but
dalerter lutilisateur de la présence
dune tension dangeruesenon isolée à
lintérieur du boitier, pouvant être dune
force suffisante pour constituer un risqué
délectrocution.
Le point dexclamation dans un triangle
équilatéral a pour but dalerter
luntilisateur de la présence
dinstructions importantes concernant le
fonctionnement et la maintenance, dans
la documentation qui accompagne
lappariel.
Safety

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Installing
Installing Your Amplier: Electrical
Considerations
The amplier has been manufactured
to comply with your local power supply
requirements, but before connecting the
unit to the supply, ensure that the voltage
(printed on the rear panel label) is correct and
corresponds with that of the local supply.
The amplier is tted with a 115/230V
tapped transformer and is internally set (from
factory) according to customer requirements.
Make sure power outlets conform to the
power requirements listed on the back of
the unit. Damage caused by connecting to
improper AC voltage is not covered by the
warranty.
Installing Your Amplier: Mechanical
Considerations
The U500DC should be used horizontally and
placed on a stable surface or other mounting
that is commensurate with the weight of the
amplier.
The mounting must also allow adequate
ventilation of the external surfaces and air
ow through the ventilation holes on the
underside and at the rear of the amplier.
Do not place in a closed cabinet or over
radiators or other heat sources.
The U500DC should not be placed close to
other equipment that is sensitive to magnetic
elds and performance may be degraded if it
is used in close proximity to other equipment
that radiates high radio frequency elds.
!
SAFETY WARNING
Where a MAINS plug or appliance coupler is used
as the disconnect device, it should remain readily
operable. Where the amplier is mounted in a rack
and permanently connected to the mains, then the
rack should be installed with a readily accessible
connector or an ALL POLE circuit breaker with 3mm
breaking distances. This unit is powered using a
3-wire power cord (C13 IEC). For safety reasons, THE
EARTH LEAD SHOULD NOT BE DISCONNECTED IN
ANY CIRCUMSTANCE. If ground loops are encountered
consult the section on XLR connections on page 9.
The wiring colours are:
230v areas 115v areas
Earth Green/Yellow Earth Green
Neutral Blue Neutral White
Live Brown Live Black
DO NOT USE THE UNIT IF THE ELECTRICAL
POWER CORD IS FRAYED OR BROKEN.
The power supply cord should be routed so that they
are not likely to be walked on or pinched by items
placed upon or against them, paying particular attention
to cords and plugs and the point where they exit from
the appliance.
ALWAYS OPERATE THE UNIT WITH THE AC GROUND
WIRE CONNECTED TO THE ELECTRICAL SYSTEM
GROUND.
Precautions should be taken so that the means of
grounding of a piece of equipment is not defeated.
DO NOT REMOVE THE COVER.
Removing the cover will expose you to potentially
dangerous voltages. There are no user serviceable
parts inside.

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Basic Connection & Set Up / AC Mains Power
Basic Connections & Set-up Explained
The U500DC receives power from the mains
via an IEC C13 AC connection and can also
be connected or disconnected from the
mains by a rocker switch on the rear panel.
Position 1 makes the connection and 0
breaks the connection. When mains power is
connected the amplier is ready to be used
and it may be put into standby or powered up
fully by pressing the standby switch on the
front panel.
The amplier should be powered off fully
when making any other connections to the
rest of the audio system.
Audio input connections can be made at the
rear of the amplier via a pair of XLR’s and
a pair of RCA connectors that will interface
directly to most other domestic audio
equipment. These are both active (on) at all
times, so it is possible to set up two alternate
sources (or even mix them should there be a
circumstance when that is desirable).
Speaker connections are also made on the
rear of the amplier and provided on 4 pairs
of binding posts to allow simple or more
advanced wiring options.
Mini Jacks are provided on the rear panel
that allow DC signals (5-12v) to remotely
control the standby/power up status of the
amplier. Two are provided to allow daisy
chaining with other parts of the system. They
are “edge triggered” which allows the remote
control to override the front panel switch or
vice versa (whichever is used last).
Connection Setup Tips
All audio system equipment should be sited
reasonably close together if possible so that
wire lengths can be kept quite short. This
approach inherently reduces ground loop
(hum) noise (by reducing the loop area) and
other interference that can be induced in the
cables although it’s not the only way***. All
equipment should also be powered from the
same mains source if possible and certainly
from the same mains phase (which is normal
in domestic house wiring).
AC Mains Power
The Ultrade U500DC is set up to operate
from either 230V nominal or 115V nominal,
50 - 60Hz AC mains. The mains cable must
contain a Safety Earth conductor and the
connection to earth must not be defeated or
tampered with in any way.
In theory the mains Live and Neutral power
conductors are inherently current balanced
and therefore no current ows in the earth
conductors; however stray capacitance, other
coupling and mostly lter components used
for compliance to EMC standards does cause
a small current to ow in most mains earth
systems. This is the source of the ground
loop hum that may need to be addressed
when wiring an audio system.

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Remote Standby Connectors
Mini Jack cables are used for remote power
up control and use the tip and outer ring for
connectivity. A positive going edge will take
the amplier out of standby and a negative
going edge will put it back into standby. The
system will work with 5V to 12V signals.
XLR Connectors
As a simple rule of thumb input connections
are best made balanced on the U500DC
XLR’s because balanced systems inherently
reject ground loop noise and, in the unlikely
event that hum does prove to be a problem,
it is also possible to break the ground
connection on Pin 1 of the XLR at one end
which usually resolves the problem simply
and does not compromise safety in any way.
Signals of 2.2V rms will put the amplier
close to full power. The standby switch will
ash red if this is exceeded.
RCA Connectors
Some audio system equipment may be
battery powered or double isolated (with no
earth wire) and typically these will provide
RCA outputs that will operate perfectly well
(without hum) on the U500DC RCA inputs,
which also provide a low impedance ground
for the cable shield. Signals of 2.2V rms
will put the amplier close to full power.
The standby switch will ash red if this is
exceeded.
The RCA inputs can also be used, if preferred,
with other grounded equipment, but the use
of short cables and common mains source
becomes critical in order to remove/reduce
ground loops. Sometimes additional ground
bonding cables may be necessary to supress
ground loops.
***Another trick, that is counter intuitive but
can be useful, is to run the audio signals
alongside the mains cables. If the mains is
all supplied from a single source this can be
thought of as a “star point”. If all audio cables
run alongside the mains cables and pass
close or over the star point, then the ground
loop area is massively reduced eliminating
the hum.
Mixed XLR and RCA Connectors
Unbalanced RCA sources can be connected
to the balanced XLR inputs and benet from
the hum rejecting properties of balanced
systems, providing two conductor cables
with an overall shield are used. For oating
sources (battery powered or double isolated
equipment) the Pin 1 shield conductor
should be connected to the signal reference
conductor at the RCA end. For grounded
sources this connection may not need to be
made (some experimentation may be needed
to minimise hum from potential ground
loops).
Balanced XLR sources can sometimes be
connected to RCA inputs, but this depends
on the nature of the driving circuit. If the
manufacturer of the balanced source
states that the signals are oating, or that
unbalanced operation is possible, then the
cable can be wired exactly as above, and
again the pin 1 connection can be optionally
connected to the signal reference conductor
at the RCA end.

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Binding Posts
Two pairs of binding posts are provided
for connection to loudspeakers. This
allows separate conductors for Tweeter
and Woofer. The Red binding posts are
positive (+) voltage, and the Black binding
posts are negative (-) voltage; they should
be connected to the red and black or +
and - connectors on the loudspeaker. For
convenience the binding posts accept
4mm “banana” connections, but bare wire
termination is recommended for permanent
installations when the binding post terminal
can be screwed down into place directly onto
the cable conductors.
Cable Types Required
The IEC C13 Main’s connector and cable
should be high quality 10A rated with
three core’s including a ground connection
which must not be disconnected under any
circumstances.
Mini Jack cables work with 3 pin or 2 pin
style connectors. Cables should be shielded
but no other special requirements are
needed.
All RCA-to-RCA connections should use high
quality cable with a single central conductor
for the signal and a braided outer conductor
that behaves as a ground reference and as a
shield against radio interference.
All XLR-to-XLR connections should use high
quality cable with a dual, twisted central
conductors for the signals (or signal and
ground reference) and a braided outer
conductor that behaves as a shield against
radio interference.
All RCA-to-XLR connections should use
high quality cable with a dual, twisted
central conductors for the signal and
ground reference plus a braided outer
conductor that behaves as a shield against
radio interference. The shield needs to be
connected at the XLR end and may optionally
be connected to the ground reference
conductor at the RCA end.
All Binding Post connections should use
high quality speaker cables with paired
conductors that are capable of delivering
high currents (10A or more) and maintaining
low impedance over the cable run.
Basic Connection & Set Up / AC Mains Power