Cambridge Audio AZUR 840A V2, Azur 840A User manual

Cambridge Audio AZUR 840A V2, Azur 840A User manual
840A V2
Your music + our passion
Class XD integrated amplifier
User’s manual
Important safety instructions
For your own safety please read the following important safety
instructions carefully before attempting to connect this unit to the
mains power supply. They will also enable you to get the best
performance and prolong the life of the unit:
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
Risk of electric
Do not open.
Risque de choc
Ne pas ouvrir.
Vorm öffnen
des gerätes.
Netzstecker ziehen.
The lightning flash with the arrowhead symbol within an equilateral
triangle is intended to alert the user to the presence of un-insulated
‘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 to the presence of important operating and maintenance
instructions in the service literature relevant to this appliance.
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 (including amplifiers) that produce heat.
9. 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 fit into your outlet, consult an electrician for
replacement of the obsolete outlet.
10. Protect the power cord from being walked on or pinched,
particularly at plugs, convenience receptacles, and the point where
they exit from the apparatus.
11. Only use attachments/accessories specified by the manufacturer.
12. Use only with the cart, stand, 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 tip-over.
13. Unplug this apparatus during lightning storms or when unused for
long periods of time.
14. Refer all servicing to qualified service personnel. Servicing is
required when the apparatus has been damaged in any way, such
as the power-supply cord or plug being 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.
WARNING - To reduce the risk of fire or electric shock, do not expose
this unit to rain or moisture.
The unit is of Class 1 construction and must be connected to a mains
socket outlet with a protective earthing connection.
The unit must be installed in a manner that makes disconnection of the
mains plug from the mains socket outlet (or appliance connector from
the rear of the unit) possible. Where the mains plug is used as the
disconnect device, the disconnect device shall remain readily operable.
Only use the mains cord supplied with this unit.
Please ensure there is ample ventilation (at least 10cm clearance all
round). Do not put any objects on top of this unit. Do not situate it on
a rug or other soft surface and do not obstruct any air inlets or outlet
grilles. Do not cover the ventilation grilles with items such as
newspapers, table-cloths, curtains etc.
This unit must not be used near water or exposed to dripping or
splashing water or other liquids. No objects filled with liquid, such as
vases, shall be placed on the unit.
WEEE symbol
The crossed-out wheeled bin is the European Union symbol for
indicating separate collection for electrical and electronic
equipment. This product contains electrical and electronic
equipment which should be reused, recycled or recovered and
should not be disposed of with unsorted regular waste. Please
return the unit or contact the authorised dealer from whom you
purchased this product for more information.
CE mark
This product complies with European Low Voltage
(89/336/EEC) Directives when used and installed according
to this instruction manual. For continued compliance only Cambridge
Audio accessories should be used with this product and servicing must
be referred to qualified service personnel.
C-Tick mark
This product meets the Australian Communications Authority’s
Radio communications and EMC requirements.
Ross Test Stamp
This product meets Russian electronic safety approvals.
FCC regulations
This equipment has been tested and found to comply with the
limits for a Class B digital device, pursuant to Part 15 of the
FCC Rules. These limits are designed to provide reasonable
protection against harmful interference in a residential installation. This
equipment generates, uses and can radiate radio frequency energy
and, if not installed and used in accordance with the instructions, may
cause harmful interference to radio communications. However, there is
no guarantee that interference will not occur in a particular installation.
If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and
on, the user is encouraged to try to correct the interference by one or
more of the following measures:
- Re-orient or relocate the receiving antenna.
- Increase the separation between the equipment and receiver.
- Connect the equipment into an outlet on a circuit different from that
to which the receiver is connected.
- Consult the dealer or an experienced radio/TV technician for help.
840A V2
IMPORTANT - The unit will become hot when in use. Do not stack
multiple units on top of each other. Do not place in an enclosed area
such as a bookcase or in a cabinet without sufficient ventilation.
Ensure that small objects do not fall through any ventilation grille. If this
happens, switch off immediately, disconnect from the mains supply and
contact your dealer for advice.
Choose the installation location carefully. Avoid placing it in direct
sunlight or close to a source of heat. No naked flame sources, such as
lighted candles, should be placed on the unit. Also avoid locations
subject to vibration and excessive dust, cold or moisture. The unit can
be used in a moderate climate.
This unit must be installed on a sturdy, level surface. Do not place in a
sealed area such as a bookcase or in a cabinet. Any space open at the
back (such as a dedicated equipment rack) is fine however. Do not
place the unit on an unstable surface or shelf. The unit may fall,
causing serious injury to a child or adult as well as serious damage to
the product. Do not place other equipment on top of the unit.
Due to stray magnetic fields turntables or CRT TVs should not be
located nearby due to possible interference.
Electronic audio components have a running in period of around a week
(if used several hours per day). This will allow the new components to
settle down, the sonic properties will improve over this time.
Power sources
The unit should be operated only from the type of power source
indicated on the marking label. If you are not sure of the type of powersupply to your home, consult your product dealer or local power
This unit has been designed to be left in Standby mode when not in
use, this will increase the life of the amplifier (this is true with all
electronic equipment). To turn the unit off completely switch off on the
rear panel. If you do not intend to use this unit for a long period of time,
unplug it from the mains socket.
Do not overload wall outlets or extension cord as this can result in a
risk of fire or electric shock. Overloaded AC outlets, extension cords,
frayed power cords, damaged or cracked wire insulation, and broken
plugs are dangerous. They may result in a shock or fire hazard.
Be sure to insert each power cord securely. To prevent hum and noise,
do not bundle the interconnect leads with the power cord or speaker
Cambridge Audio warrants this product to be free from defects in
materials and workmanship (subject to the terms set forth below).
Cambridge Audio will repair or replace (at Cambridge Audio's option)
this product or any defective parts in this product. Warranty periods
may vary from country to country. If in doubt consult your dealer and
ensure that you retain proof of purchase.
To obtain warranty service, please contact the Cambridge Audio authorised
dealer from which you purchased this product. If your dealer is not
equipped to perform the repair of your Cambridge Audio product, it can be
returned by your dealer to Cambridge Audio or an authorised Cambridge
Audio service agent. You will need to ship this product in either its original
packaging or packaging affording an equal degree of protection.
Proof of purchase in the form of a bill of sale or receipted invoice, which
is evidence that this product is within the warranty period, must be
presented to obtain warranty service.
This Warranty is invalid if (a) the factory-applied serial number has been
altered or removed from this product or (b) this product was not
purchased from a Cambridge Audio authorised dealer. You may call
Cambridge Audio or your local country Cambridge Audio distributor to
confirm that you have an unaltered serial number and/or you purchased
from a Cambridge Audio authorised dealer.
This Warranty does not cover cosmetic damage or damage due to acts of
God, accident, misuse, abuse, negligence, commercial use, or modification
of, or to any part of, the product. This Warranty does not cover damage due
to improper operation, maintenance or installation, or attempted repair by
anyone other than Cambridge Audio or a Cambridge Audio dealer, or
authorised service agent which is authorised to do Cambridge Audio
warranty work. Any unauthorised repairs will void this Warranty.
This Warranty does not cover products sold AS IS or WITH ALL FAULTS.
Some countries and US states do not allow the exclusion or limitation
of incidental or consequential damages or implied warranties so the
above exclusions may not apply to you. This Warranty gives you specific
legal rights, and you may have other statutory rights, which vary from
state to state or country to country.
For any service, in or out of warranty, please contact your dealer.
Plug Fitting Instructions (UK Only)
To clean the unit, wipe its case with a dry, lint-free cloth. Do not use
any cleaning fluids containing alcohol, ammonia or abrasives. Do not
spray an aerosol at or near the unit.
The cord supplied with this appliance is factory fitted with a UK mains plug fitted
with a 5 amp fuse inside. If it is necessary to change the fuse, it is important that
a 5 amp one is used. If the plug needs to be changed because it is not suitable
for your socket, or becomes damaged, it should be cut off and an appropriate
plug fitted following the wiring instructions below. The plug must then be disposed
of safely, as insertion into a mains socket is likely to cause an electrical hazard.
Should it be necessary to fit a 3-pin BS mains plug to the power cord the wires
should be fitted as shown in this diagram. The colours of the wires in the mains
lead of this appliance may not correspond with the coloured markings identifying
the terminals in your plug. Connect them as follows:
Battery disposal
Please dispose of any discharged batteries according to local
environmental/electronic waste disposal guidelines.
Before making any connections to loudspeakers, make sure all power
is turned off and only use suitable interconnects.
These units are not user serviceable, never attempt to repair,
disassemble or reconstruct the unit if there seems to be a problem.
A serious electric shock could result if this precautionary measure is
ignored. In the event of a problem or failure, please contact your dealer.
The wire which is coloured BLUE must be
connected to the terminal which is marked
with the letter ‘N’ or coloured BLACK.
The wire which is coloured BROWN must be
connected to the terminal which is marked
with the letter ‘L’ or coloured RED.
The wire which is coloured GREEN/YELLOW
must be connected to the terminal which is
marked with the letter ‘E’ or coloured GREEN.
If a standard 13 amp (BS 1363) plug is used,
a 5 amp fuse must be fitted, or if any other type of plug is used a 5 amp fuse
must be fitted, either in the plug or adaptor, or on the distribution board.
Limited warranty
Important safety instructions..........................................................2
Thank you for purchasing this Azur 840A V2 Class XD Integrated
Amplifier. We hope that you will enjoy many years of listening
pleasure from it.
Limited warranty ...........................................................................3
The 840A V2 features our unique proprietary amplifier topology; Class
XD™, designed to eliminate crossover distortion at low signal levels.
Introduction .................................................................................4
By actively displacing the crossover point this technology creates a
region of pure Class-A operation where the crossover zone would
otherwise be before moving into an enhanced form of Class B at higher
levels. It should not be confused with Class AB, which gives a small
area of Class A, but at the cost of higher distortion as soon as the
signal level moves outside the AB area. Class XD circuitry not only
removes crossover distortion from the zero-crossing point but also
reduces distortion in the other parts of the amplifier's output range.
Rear panel connections.................................................................5
Front panel controls .....................................................................6
Remote control ............................................................................7
iPod compatibility .........................................................................7
Connections ................................................................................8
Operating instructions .................................................................10
Amplifier setup ...........................................................................10
Multi-Room connections .............................................................12
Custom installation use...............................................................13
CAP5 protection system ..............................................................14
Troubleshooting ..........................................................................15
Technical specifications ...............................................................15
This V2 version of the 840A features our latest development of Class
XD with many tweaks and enhancements from our on-going research
resulting in our best sounding implementation to date.
A white paper on this patent pending technology is available on our
Please note that because of the Class XD technology the 840A V2 runs
slightly warmer than a conventional Class B/AB amplifier and the
ventilation slots on the top of the unit must not be obstructed.
Other features include the use of precision resistor ladders switched by
gold plated relay contacts for the volume and balance controls rather
than the more common solid-state or volume potentiometer schemes.
Volume is controllable in 1 dB steps over most of the range, giving very
fine control, an accurate logarithmic law and superbly accurate channel
balance. Input switching is also by high quality gold contact relays.
The 840A V2 features separate transformer secondaries for left and
right channels, twin rectifiers and separate PSU's for dual mono
operation of the left and right power amplifiers. A separate transformer
supplies the preamp making the 840A V2 effectively a Pre and Power
amp combination in one box.
Make sure you register your purchase.
By registering, you’ll be the first to know about:
G Future product releases
G Software upgrades
G News, events and exclusive offers plus
This guide is designed to make installing and using this product
as easy as possible. Information in this document has been
carefully checked for accuracy at the time of printing; however,
Cambridge Audio's policy is one of continuous improvement,
therefore design and specifications are subject to change
without prior notice.
This document contains proprietary information protected by
copyright. All rights are reserved. No part of this manual may be
reproduced by any mechanical, electronic or other means, in any
form, without prior written permission of the manufacturer. All
trademarks and registered trademarks are the property of their
respective owners.
Incognito and Incognito Ready are trademarks of Cambridge
Audio Ltd. All rights reserved.
Input 1 features a balanced input using XLRs giving optimal
performance with equipment such as the matching 840C Upsampling
CD player which features balanced outputs.
The casework combines massive structural rigidity with careful damping
and control of acoustic resonance. An Azur Navigator remote control is
also provided, giving full remote control of your amplifier in an attractive
and easy to use handset.
We have also included support for multi-room use. By plugging in one
or two external Cambridge Audio Incognito keypads and a power supply
unit your amplifier can become the hub of a simple multi-room system.
In addition, Control Bus Input/Output, IR Emitter Input and RS232
control are featured making it easy to integrate the 840A V2 into a
Custom Installation system if desired.
Your amplifier can only be as good as the system it is connected to.
Please do not compromise on your source equipment, speakers or
cabling. Naturally we particularly recommend models from the
Cambridge Audio Azur range. These have been designed to the same
exacting standards as this amplifier. Your dealer can also supply
excellent quality Cambridge Audio interconnects to ensure your system
realises its full potential.
Thank you for taking the time to read this manual; we do recommend
you keep it for future reference.
Class XD Technology International Patent Pending Cambridge
Audio Ltd.
© Copyright Cambridge Audio Ltd 2008
A-BUS and A-BUS Ready are registered trademarks of
LeisureTech Electronics Pty Ltd Australia. This product may be
covered by one of more of the following patents US 7,181,023,
6,389,139, EP 1004222, AU 739808, NZ 502982, Mexico
Z41196, Canada CA2301062.
iPod and Apple are trademarks of Apple Inc., registered in the
U.S. and other countries.
Matthew Bramble,
Cambridge Audio Technical Director
and the Amplifier design team
840A V2
Rear panel connections
Input 1 Balanced Audio
Input 1
1 Power On/Off
Switches the unit on and off.
2 AC power socket
Once you have completed all connections to the amplifier, plug the AC
power cable into an appropriate mains socket then switch on. Your
amplifier is now ready for use.
Loudspeaker terminals
Two sets of loudspeaker terminals are available, A (main loudspeaker
terminals) and B (secondary loudspeaker terminals). Both sets of
speakers can be turned on and off independently. Connect the wires
from your left channel loudspeaker to the LEFT + & - terminals, and
the wires from the right channel loudspeaker to the RIGHT + & terminals. In each case, the red terminal is the positive output and the
black terminal is the negative output.
Care should be taken to ensure no stray strands of wire short the
speaker outputs together. Please ensure that the loudspeaker terminals
have been tightened completely to provide a good electrical
connection. It is possible for the sound quality to be affected if the
screw terminals are loose.
IR - Four IR outputs for remote control of source equipment.
Please refer to the ‘Multi-Room’ section of this manual for more
information on connections and set-ups.
Input 1 Balanced Audio
Input 1 features either unbalanced (phono/RCA) or balanced (XLR)
connections. Either type may be used but not both at the same time.
The balanced connection is the higher quality option and can reject
noise and interference in the cable when used with other equipment
that supports this function. An XLR connector is wired Pin 1 - Ground;
Pin 2 - Hot (in-phase); Pin 3 - Cold (phase-inverted).
Use the Balanced/Unbalanced switch (Item 9) to select the connection
type you wish to use. When using either the balanced or unbalanced
input, make sure that no cables or equipment are connected to the
unused input, as this may degrade operation. The unused input does
not require to be terminated and this should not be done.
Input 1 Balanced/Unbalanced switch
Use to select the connection type for Input 1.
Inputs 1-7
Note: When using one pair of speakers, use speakers with a nominal
impedance of between 4-8 ohms. When using two pairs of speakers,
use speakers with a nominal impedance of between 6-8 ohms. Please
also note that when multiple speakers are connected across the
amplifier’s outputs, the load (as seen by the amplifier) is reduced. This
will make the amplifier work harder, and hotter!
These inputs are suitable for any 'line level' source equipment such as
CD players, DAB or FM/AM tuners etc.
4 IR (Infrared) Emitter In
Allows modulated IR commands from multi-room systems to be
received by the amplifier. Commands received here are not looped out
of the Control Bus. Refer to the ‘Custom installation’ section for more
Connect to a tape deck or to the analog output sockets on a MiniDisc,
portable digital music player or CD recorder using an interconnect cable
from the recorder's Line Out sockets to the amplifier's Tape In sockets.
Note: These inputs are for analog audio signals only. They should not be
connected to the digital output of a CD player or any other digital device.
5 Control Bus
In - Allows un-modulated commands from multi-rooms systems or
other components to be received by the unit.
Out - Loop out for control bus commands to another unit. Also allows
the 840A V2 to control some Cambridge Audio units.
The RS232C port allows external serial control of the 840A V2 for
custom install use. A full command set is available on the Cambridge
Audio website at This port can also be
used by Cambridge Audio service personnel for software updates.
A-BUS™ Ready / Incognito Ready™
multi-room outputs
PSU - Connect an Incognito PS5 to supply power to the connected
multi-room keypads/speakers.
Keypad 1/2 - Connect one or two Incognito A-BUS KP10 keypads (or
other A-BUS compatible keypads) using CAT-5/5e cable. Incognito
AS10 Active Ceiling Speakers can also be connected here.
Tape/Rec In/Out
The Tape Input circuit of the 840A V2 is a "monitor" type, different from
the other 7 inputs. For the 7 normal inputs, the source selected for
listening to will be sent out of the Tape Out for recording. The source
currently being listened to and (optionally) recorded is then shown on
the front panel display.
However, when the Tape Input is selected a solid circle will appear
beside TAPE MON indicating that the Tape Input is now being listened
to with a different source being sent out of the Tape Out for recording.
The recording source is also shown by a solid circle by the selected
input and can be changed by pressing the other source buttons.
To switch Tape Monitor off, simply press the Tape Mon input select
button again, toggling this function off.
This feature is most useful when using 3-head analog cassette decks
which allow the signal being recorded to be played back live off tape
(via a 3rd head) whilst it is simultaneously recorded. It is then possible
by toggling the Tape Monitor input on and off to compare directly in real
time the original and recorded signal so that adjustments to the
recording parameters of the tape machine can be made (consult the
manual of your 3-head analog cassette deck for full details).
Preamp Out
Connect these sockets to the inputs on an external power amplifier(s)
or active subwoofers etc.
Front panel controls
azur 840A
Class XD Integrated Amplifier
Standby / On
Speaker A/B
Note: As default the 840A V2 ramps the volume up or down when
switched on and when going into Standby mode. This feature can be
turned off if desired; please refer to the ‘Amplifier setup’ section of this
manual for more information.
Allows for the connection of stereo headphones with a ¼" Jack plug.
Headphones with an impedance of between 32 and 600 ohms are
recommended. When the headphones are connected, the loudspeaker
relays are released switching off the output to the loudspeakers
(speakers A and B).
Speaker A/B
Press to scroll through the speaker sets connected to the loudspeaker
terminals on the back panel (speaker sets A, B or A and B). This can
be used for listening to an extra set of loudspeakers in another room.
Please note that care should be taken when choosing speakers if two
loudspeakers are going to be used on each channel. If the combined
resistance measured on the loudspeaker terminals is too low the
amplifier may not switch out of Standby mode until a suitable load
resistance is detected. For more information refer to the CAP5 section
of this manual.
Note: When using one pair of speakers, use speakers with a nominal
impedance of between 4-8 ohms. When using two pairs of speakers,
use speakers with a nominal impedance of between 6-8 ohms each.
8 Display
LCD used to control the 840A V2. Please refer to the ‘Operating
instructions’ and ‘Amplifier setup’ section of this manual for more
Bass and Treble
Press to release and rotate to allow subtle adjustments to the tonal
balance of the sound.
1 Standby/On
Switches the unit between Standby mode (indicated by dim power LED)
and On (indicated by bright power LED). Standby is a low power mode
where the power consumption is less than 10 Watts. The unit should
be left in Standby mode when not in use.
This control gives the audio signal a more direct path to the power
amplifier stage of your amplifier, bypassing the tone control circuits for
the purest possible sound quality.
The Bass/Treble icon (
) appears in the display when the bass and
treble circuit is active (in circuit) and is not present when they are
Note: Direct can be set on or off individually for each input. This
settting is recalled each time a source is selected.
Use to increase/decrease the level of the sound from the outputs of the
amplifier. This control affects the level of the loudspeaker output, the
pre-amp output and the headphone output. It does not affect the Tape
Out connections.
As the 840A V2 uses a very high quality passive resistor ladder
switched by relays to achieve volume and balance, audible
control clicks can be heard from the unit when the volume or
balance is adjusted.
The Volume control is also used in navigating the 840A V2 System
Configure menus on the front panel display.
Press to switch between Volume and Balance modes. Press and hold
to to enter the 840A V2 System Configure menu.
Infrared sensor
Receives IR commands from the supplied Azur remote control. A clear
unobstructed line of sight between the remote control and the sensor
is required.
Input select buttons
Push the appropriate input selection button to select the source
component that you wish to listen to (highlighted by a solid circle on
the display). The signal selected is also fed to the Tape Out sockets so
that it may be recorded. The input should not be changed whilst
recording (but the recorded signal can be checked using the tape input
Tape Monitor).
Please refer to the ‘Operating instructions’ section of this
manual for more information on some functions of these
840A V2
Remote control
iPod compatibility
The 840A V2 is supplied with an Azur Navigator remote control that
operates both this amplifier and Cambridge Audio Azur CD players.
Insert the supplied AAA batteries to activate.
To make use of the iPod functionality, your iPod dock must be connected
to ‘Input 4’.
The functions relevant to the amplifier are as follows:
To use the Azur remote to control the docked iPod, hold down the
Input 4 button whilst pressing one of the following buttons:
Switches the amplifier between On and Standby mode.
Numerical buttons 1-8
Press to change the input source to the amplifier. Button 8 toggles Tape
Monitor on/off.
Press to play the iPod, press again to pause play.
Press once to skip forwards or backwards one track.
Adjust the backlight of the front panel
display; bright, dim or off.
The 840A V2 remote can also control the basic functions of Apple iPod
models when mounted in Cambridge Audio’s iPod docks, Apple’s
Universal Dock or other docks compatible with the Apple Remote. Refer
to your dock’s instruction manual on how to connect it to your amplifier.
Press to switch between Volume and
Balance modes.
Mutes the audio on the amplifier. The
mute mode is indicated by MUTE
appearing and the volume level being
replaced by two flashing dashes in the
display. Press again to cancel mute.
Increase or decrease the volume of the
amplifier output.
The functions relevant to a connected
Azur CD player are as follows:
Opens and closes the disc tray.
Play /
Stop /
Press the relevant button to play, stop
or pause the CD.
Right Skip - Press once to skip forward
by one track on the CD. Press and hold
to skip forwards through tracks.
Left Skip - Press once to skip backward
by one track on the CD. Press and hold
to skip backwards through tracks.
Press and hold to search within the
selected track. Right button to fast
forward, left button to rewind.
Repeat, Random, Remain
Refer to the ‘Operating instructions’
section of your CD player manual for
information on the functions of these
When designing our amplifiers we have tried to include features that
allow you to connect your system in various ways. The inclusion of
features such as Pre-Out and Speaker B connections mean that you
can flexibly configure your system depending on your requirements.
Basic connections
The diagram below shows the basic connection of your amplifier to a
CD player and a pair of loudspeakers.
Speaker B connections
The Speaker B connections on the back of the amplifier allow for a
second set of speakers to be used (i.e. speakers located in another
room). The Speaker A/B button on the front panel allows this second
set of speakers to be switched on and off.
Note: When using two pairs of speakers, use speakers with a nominal
impedance of between 6-8 ohms each minimum.
Note: If using Input 1 (Unbalanced), the Input 1 switch must be in the
‘Unbalanced’ position.
840A V2
840A V2
Tape connections
Preamp Out connections
The diagram below shows how to connect the amplifier to a tape
recorder or other source with a record and monitor connection.
The Preamp Out sockets are for connecting to the input sockets of a
power amplifier or active subwoofer. The diagram below shows how to
connect the amplifier to an active subwoofer via the Line In inputs on
the subwoofer.
840A V2
Active subwoofer
840A V2
Tape / MD player
Please note that either of the tape loop outputs can be used (as they
are both the same signal in parallel).
840A V2
Balanced audio connections
The diagram below shows how to connect the 840A V2 to the Azur
840C Upsampling CD player using the Balanced Audio inputs via threepin XLR connectors. The 840A V2 can also be connected to nonCambridge Audio sources with balanced outputs).
Note: The Input 1 switch must be in the ‘Balanced’ position.
840A V2
Balanced connections in an audio system are designed to reject
electrical noise, from power wiring etc, and also the effects of noise
currents flowing through ground connections. The basic principle of
balanced interconnection is to get the signal you want by subtraction,
using a three-wire connection. One signal wire (the hot or in-phase)
carries the normal signal, while other (the cold or phase-inverted)
carries an inverted version. The balanced input senses the difference
between the two lines to give the wanted signal. Any noise voltages that
appear identically on both lines (these are called common-mode
signals) are cancelled by the subtraction. An additional advantage is
that the connection effectively carries twice the signal level and so
improves the signal-to-noise ratio.
The 840A V2 and 840C are designed to work at their highest
performance when a balanced interconnect is used.
Operating instructions
Amplifier setup
The 840A V2 has a custom-made display on the front of the unit
showing the current status and allowing you to access the 840A V2
System Configure menus. Here you can adjust the listening settings of
the amplifier to personal preference. The menu system is easy to
navigate and control, simply by using the input select buttons to turn a
feature on (solid circle) or off (no circle) and the volume control knob
to increase/decrease settings.
The 840A V2 features many advanced settings that allow it’s use to be
customised to user preference. The inputs can be named to reflect the
actual source units you have, each input can be trimmed so that each
sounds the same in terms of loudness when you switch between them
and other options.
Changing input names / source naming
Adjust the volume control knob on the front panel (or using the remote
control). The display will show the change in volume in decibels (dB).
‘OdB’ indicates maximum volume while lower volume settings progress
into the negative range. This can also be changed to volume units
(0-96) in the System Configure menu.
Press and hold the relevant input select button for four seconds to
change its name. For example, if Input 1 is a CD player, name it “CD”
etc. Letters are selected by turning the volume control to scroll through
the available characters. Press LEFT or RIGHT to select which character
you wish to edit. Press EXT CHAR to access an extended character set.
Press OK to confirm and exit the input name change menu.
Speaker A/B
System Configure menu
Speaker A/B
Press the Speaker A/B button to scroll through the speaker sets
connected via the rear panel: speakers A, B or A and B.
Press and hold the Mode button to access the System Configure menu.
The menu options are Clip detector, LCD brightness, Speaker short
detector, Input gain trim, Volume ramp, Volume display, Front IR and
Fixed input gain.
To exit the System Configure menu and its sub-menus, press the Mode
button again.
Press the Mode button to enter Balance mode. BALANCE will appear
on the display and can be adjusted using the volume control. Press the
Mode button again to return to Volume mode or wait 5 seconds for the
840A V2 to automatically exit Balance mode.
Clip detector / Speaker short detector
Refer to the ‘CAP5’ section of this manual for more information on the
Clip and Short detection features of the 840A V2, as both can be
enabled (default) or disabled.
LCD brightness
Bass and Treble
These controls allow subtle adjustments to the tonal balance of the
sound. Modify the sound through your loudspeakers and the Pre-Out
sockets only; they do not affect the signals sent through the Tape Out
connections. With a well produced CD and a good system the tone
controls are unnecessary and can be switched out by pressing the
Direct button:
In the System Configure menu press the LCD input select button to
scroll through bright/dim/off settings for the front panel display. Press
the Mode button to exit.
Volume ramp
This completely removes them from the signal path for maximum
fidelity. If the musical recording is of poor quality or other factors are
affecting the sound quality, if desired you can adjust the tone controls
to compensate. To use the tone controls press the Direct button so that
the Bass/Treble icon (
) lights in the display indicating that they are
active and direct mode is Off. Now press the Bass or Treble controls
themselves to release them and allow adjustment; push them back in
when finished:
The 840A V2 stores whether direct mode is on or off for each input
individually, for example it is possible to have the tone controls
automatically active for the Tuner source but not the CD source.
The 840A V2 automatically ramps the volume down when going into
Standby mode and up when coming out of Standby mode. To turn this
feature off, press the VOL RAMP input select button in the System
Configure menu and set to off. Press the Mode button to exit.
Volume display
840A V2
To set a fixed volume for a source, select FIXED INP in the System
Configure menu:
To change the volume display from decibels (-95 to 0dB) to arbitrary
volume units (0 to 96 units) select VOL DB in the System Configure
menu. Press the input select button to turn off the volume in decibels.
Press the Mode button to exit.
Front IR
Select the input required and set the fixed gain using the volume
control (the OFF setting does not disable the input but leaves the input
gain subject to the volume control which is the default setting). When
a source has a fixed input, the balance is always set to neutral. Press
the Mode button to exit.
On/Off control menu
Used in conjunction with Custom Installation (C.I.) systems or IR
repeater systems, it may be desirable to disable the front panel IR by
setting FRONT IR to off (press the input select button to turn off). Press
the Mode button to exit.
When going in/out of Standby mode the 840A V2 can automatically turn
on and off other connected Cambridge Audio Azur models that have
control bus sockets. For this feature to work the units must be connected
together (see diagram) by RCA/phono leads. The sockets are colourcoded orange on the rear panels of compatible Azur models. Loop out
from the 840A V2 Control Bus Out to the Control Bus In on another Azur
model (e.g. 840C). Continue the chain to other Azur models if required.
640T V2.0
Input gain trim
Manufactured in an
ISO9002 approved facility
Line Output
Power Off
Control Bus
IR Emitter
Digital Outputs
Risk of electric shock.
Do not open.
azur 640T DAB/FM Tuner V2.0
50 Ohms
Designed in London, England
Power Rating: 230V AC ~ 50Hz
Risque de choc electrique.
Ne pas ouvrir.
Max Power Consumption: 15W
Vorm öffnen des gerätes.
Netzstecker ziehen.
Line Output
50 Ohms
The relative levels of the inputs can be adjusted by gain trim. This
allows each to be adjusted so that each sounds the same in terms of
average loudness when you switch between them. Pick the loudest
sounding source and trim its level until it matches the average
perceived level of the others. Repeat this process if other sources also
stand out as louder than the average.
To set the input gain trim for each source, select INP TRIM in the
System Configure menu. Select the input required and use the volume
control to set the gain between 0 and -12 dB (the available range is
restricted if the volume is set very low). Press the Mode button to exit.
840A V2
Fixed level inputs
Any input of the 840A V2 is able to be set for fixed gain. Whenever this
input is selected the gain will automatically go to this value and will not
be adjustable by the volume control. This feature allows the 840A V2 to
be effectively used as a stereo power amplifier (for that selected input
only). For example, as well as operating as a pure stereo amplifier, the
840A V2 can provide the amplification for the front left and right channels
of a surround sound setup with an AV receiver providing amplification for
the other channels and controlling the overall system volume.
When listening in stereo use the 840A V2 and connected stereo sources
as normal for best possible sound quality. For surround sound, select the
fixed level input you have chosen on the 840A V2 and now use the
AV receiver to control the volume, select connected surround sound
sources etc. You may wish to re-name the fixed level input as “A/V mode”
or similar on the 840A V2. Make connections as below, the left and right
preamp outputs of the AV receiver connect to the fixed gain input chosen
on the 840A V2. As the gain can be fixed to any value it is easy to match
the level of the 840A V2 to that of the other AV channels.
Now while the 840A V2 is on press and hold the Standby/On button
until ON/OFF CTR appears on the display:
Standby / On
Select the connected Azur models by pressing the appropriate input
select button. For example, CA XXXC for an Azur CD player (540C V2,
640C V2), CA XXXD for an Azur DVD player, CA DAB T for an Azur DAB
tuner etc.
Press ON & OFF to scroll through the options of ON (turns all Azur units
on only), OFF (turns all Azur units into Standby only) or ON & OFF (turns
all Azur units on and into Standby mode).
Press OK to confirm and exit.
840A V2
AV receiver
Multi-room connections
The 840A V2 features Incognito Ready/ABUS Ready outputs, allowing multi-room
capability. One or two amplified keypads
can be plugged into the 840A V2 (using
CAT-5/5e cable and RJ45 plugs) to
provide multi-room audio in one or two
secondary rooms or zones. The keypads are powered by an external
PSU (also required) through the CAT-5/5e cables and no mains
connection is required in the secondary rooms.
Speakers (e.g. SS10)
connected via
speaker cable
Connections to the 840A V2’s Incognito Ready / A-BUS Ready outputs
are made by Cat-5 cable (terminated with an RJ45 jack plug). The RJ45
plug must be wired to the EIA/TIA 568A wiring standard:
Wire colours:
1. Green/White
2. Green
3. Orange/White
4. Blue
5. Blue/White
8 7 6 5 4 3 2 1
1 2 3 4 5 6 7 8
Plug view from
contact end
View into
6. Orange
7. Brown/White
8. Brown
KP10-EU keypad
CAT-5/5e (up to 30m / 100ft)
840A V2
azur 840C
Upsampling Compact Disc Player
Standby / On
Crimp wires
securely in place
To allow control of your source equipment from the remote rooms an
IR emitter (IR10) is plugged into one of the IR outputs on the rear of
the unit and then attached over the IR window of the source unit.
Alternatively, on our own products that feature IR emitter Inputs, a minijack to mini-jack lead can be used. Commands received by the keypads
can now be sent back to the source equipment via the 840A V2.
It is then possible to control the source equipment from the remote
rooms by using the source equipment's own remote controls or through
a learning remote. The Incognito LR10 Learning Remote can fully
control the keypads, “learn” the source's remote control codes
(including those from other manufacturers) and change source input on
the 840A V2 etc.
On the front panel display of the 840A V2 the extra multi-room zones
are indicated by a circle outline next to the input source (see Fig. 1).
When listening to the same source, the circle outline and solid circle
overlap (see Fig. 2).
Mini-jack lead
Gather pairs, trim
and insert into
RJ45 plug
Fig. 1 - One or both keypads are listening to a different source (Input 2)
to the amplifier (Input 1).
The 840A V2 is Incognito Ready Type II, which means the keypads can
operate independently of the amplifier in terms of volume/bass/treble
etc, be independently turned on and off, and can also listen to a
different source from that which is currently selected on the amplifier.
However, both keypads can only listen to the same source.
A-BUS is a standard that allows compatibility between different
manufacturers equipment, so A-BUS compatible keypads from other
manufacturers can also be used. If used with our own Incognito KP10
keypads, there are some extra features such as the ability to change
source on the 840A V2 from the keypad (EU model shown here):
Order of selection:
1. Input 1
2. Input 2
3. Input 3
4. Input 4
5. Input 5
6. Input 6 (Tape)
Fig. 2 - One or both keypads are listening to the same source (Input 2)
as the amplifier (Input 2).
For further details on the Incognito multi-room system please contact
your local Cambridge Audio dealer or visit:
840A V2
Custom installation (C.I.) use
Control Bus
The 840A V2 features a Control Bus input/output IR Emitter
that allow un-modulated remote control commands
(positive logic, TTL level) to be received electrically
by the unit and looped to another unit if desired.
These control commands are typically generated
by custom installation (multi-room) systems or remote IR receiver
systems. The Control Bus sockets are colour-coded orange.
An IR Emitter Input is also provided that allows modulated IR remote
control commands to be received electrically by the unit. Commands
on this input operate the unit only and are not looped out demodulated
on the Control Bus Output.
An RS232C port is also featured which allows the 840A V2
to be controlled by C.I. systems.
In addition the units feature ‘direct’ IR/Control codes as well as toggle
codes for some of their features to simplify programming custom
installation systems. Special direct On/Off and Mute commands can be
accessed on the supplied remote control for teaching into C.I. systems
as follows:
1. Press and hold the Standby/On button. The remote first generates
it's standby (toggle) command. Keep the button held down, after 12
seconds an amplifier “On” command will be generated. If the button
is kept held down for a further 12 seconds, an amplifier player “Off”
command is generated.
2. Press and hold the Mute button. The remote first generates it's mute
(toggle) command. Keep the button held down, after 12 seconds a
“Mute on” command will be generated. If the button is kept held
down for a further 12 seconds, a “Mute off” command is generated.
A full code table and RS232 protocol for this product is available on the
Cambridge Audio website:
CAP5 - Fiveway protection system
Cambridge Audio has developed a proprietary protection system to
ensure reliability and a long life for its amplifiers and the speakers they
are connected to. Note: Due to the required sensitivity of the CAP5
system, it is possible that mains power disturbances can falsely trigger
CAP5 in extreme situations. This protection system comprises of five
main protection methods:
4. Short circuit detection
Indication - Unit has not come out of Standby, display flashes “SPKR
SHORT”. Press the INFO input select button for a brief on-screen
description and remedy, or read below for more information.
1. DC detection
Indication - Unit has switched off during operation, display flashes “DC
ERROR”. Press the INFO input select button for a brief on-screen
description and remedy, or read below for more information.
Description - During power up from Standby CAP5 performs a check on
the loudspeaker terminals to see if a short across the terminals has
been accidentally introduced (display flashes “SPKR CHECK”). If the
resistance measured across the loudspeaker terminals is too low the
unit will stay in Standby mode until the fault has been removed and
Power up is re-attempted (display flashes “SPKR SHORT”).
Description - CAP5 offers loudspeaker protection if the output of the
amplifier goes to a high constant voltage (DC) because of some internal
fault. This is a rare fault although detecting it could just save those
expensive loudspeakers.
Remedy - Due to the necessary sensitivity of the DC protection circuit,
extremely hard clipping of the amplifier may cause DC protection to be
triggered. If this fault occurs press the RESET input select button, then
press the Standby/On button to power up again and check operation
with a reduced volume level. If the DC fault occurs again please contact
your dealer for service.
Remedy - User related fault. There may be a short circuit between the
loudspeaker terminals. Press the RESET input select button and check
all loudspeaker connections before attempting to switch the unit out of
Standby (display will flash “SPKR CHECK” then “SPKR OK” when short
circuit fixed).
It is possible to disable the short circuit detection feature by pressing
the SHORT DT button to off when in the 840A V2 System Configure
menu, but it is not recommended. This would only be required if the
loudspeakers have very low DC resistance.
5. Intelligent clipping detection
Indication - Volume is reduced automatically, “CLIPPING” appears on
the front panel display.
2. Over temperature detection
Indication - Unit has switched off during operation, display flashes
“OVER TEMP”. Press the INFO input select button for a brief on-screen
description and remedy, or read below for more information.
Description - Over temperature is caused by a combination of high
listening levels and low impedance speakers. CAP5 includes
temperature detection which constantly monitors the heat generated
by the output transistors. If the monitored temperature reaches a high
level (suitably within the limits of the output devices) the amplifier will
automatically switch into a fault mode. The unit should ideally be left
for 15 minutes in this state to cool down adequately. If the unit has not
fully cooled down then the temperature may reach the limit soon after
the amplifier is powered up. If the loudspeaker impedance is low the
temperature of the amplifier may rise faster as the amplifier is working
harder. If the amplifier is mounted in a cabinet or the ventilation slots
are obstructed the over temperature detection may activate/reactivate
after a short listening time.
Remedy - User related fault. The internal temperature of the output
transistors has reached the over temperature limit. Press the RESET
input select button and leave the unit for 15 minutes to cool down
before pressing the Standby button to resume normal operation.
3. Overvoltage/overcurrent detection
Description - CAP5 offers V/I (voltage/current) protection by constantly
monitoring the output transistors to keep them working inside their
Safe Operating Area (SOA). The SOA is a set of limits given by the
output transistor manufacturer to ensure reliability. The V/I protection
has been incorporated within the amplifier circuitry to provide a fast
response to temporary overload conditions. When the V/I protection is
triggered the unit will continue to operate but distortion may be heard
as the unit protects the output transistors.
Remedy - Reduce the volume. If distortion is still present, check the
speaker connections and ratings.
Description - CAP5 has the ability to detect when the amplifier starts to
clip or overdrive at its output, which can damage loudspeakers, and
degrade the sound. Clipping distortion
is caused at high volume levels when
the output signal attempts to go
outside the maximum voltage that the
amplifier can provide, causing the tops
of the signal to flatten off. When CAP5
detects clipping the volume will be
automatically reduced down until CAP5
detects an undistorted output.
It is possible to disable the clipping detection feature by pressing the
CLIP DT button to off when in the 840A V2 System Configure menu.
Note: Disabling the clipping detection is not advised as this feature has
been added deliberately to protect the amplifier and loudspeakers.
840A V2
Technical specifications
There is no power
Power Output
120W RMS into 8 Ohms
200W RMS into 4 Ohms
THD (unweighted)
< 0.001% 1 kHz
at 80% of rated power
Ensure the AC power cord is connected securely.
Ensure the plug is fully inserted into the wall socket and is switched on.
Check fuse in the mains plug or adaptor.
< 0.01% 20 Hz - 20 kHz
at 80% of rated power
There is no sound
Make sure the unit is not in Standby mode.
Frequency Response
10 Hz - 50 kHz +/- 1 dB
Check that source component is properly connected.
S/N ratio (ref 1W/8 Ohm)
> 93 dB
Input impedances
Input 1 (balanced) 20 kOhm
Inputs 2-7 20 kOhm
Tape Input 20 kOhm
Make sure unit is not in mute mode.
Power Amp damping
> 110 at 1 kHz
There is no sound on one channel
Max power consumption
Check speaker connections.
Minimum power
Active (no signal) 70W
Standby 7W
Check interconnects.
Bass & Treble controls
Shelving type
Max bass boost/cut +/- 10 dB at 10 Hz
Max treble boost/cut +/- 7.5 dB at 20 kHz
Dimensions (H x W x D)
115 x 430 x 385mm
(4.5 x 16.9 x 15.2”)
15.0kg (33Lbs)
Check that TAPE MON is not switched on (unless tape input is required).
Check that your speakers are properly connected.
If using Speaker B terminals check they are switched on.
Ensure that balance control is in the correct position.
There is a loud buzz or hum
Check turntable or tone arm for ground and connection lead fault.
Ensure no interconnects are loose or defective.
Ensure that your tape deck/turntable is not too close to the amplifier.
Unable to make or play tape recordings
Check that TAPE MON and TAPE OUT have been connected correctly.
There is weak bass or diffused stereo imaging
Ensure that speakers are not wired out of phase.
Message on display flashing
See section on CAP5 protection system.
The remote handset will not function
Check that the batteries have not expired.
Ensure that nothing is blocking the remote sensor.
For more frequently asked questions (FAQ’s), technical advice and
information on getting the most out of your 840A V2, please visit the
Support section on Cambridge Audio’s website:
For all servicing, in or out of warranty, please contact your dealer.
Cambridge Audio is a brand of Audio Partnership Plc
Registered Office: Gallery Court, Hankey Place
London SE1 4BB, United Kingdom
Registered in England No. 2953313
© 2008 Cambridge Audio Ltd
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF