AZUR 540A - Amplificateur intégré CAMBRIDGE AUDIO - Free user manual and instructions

USER MANUAL AZUR 540A CAMBRIDGE AUDIO

INTRODUCTION Thank you for purchasing this Cambridge Audio azur series amplifier. lt is the result of our most extensive ever research and development program in over three decades of producing high quality audio products. We hope that you will appreciate the results and enjoy many years of listening pleasure.

About this amplifier

The design of any purist audio amplifier is mainly centred on two main areas, the Power Supply and the driver stage's ability to drive the output stage effectively. We at Cambridge Audio have researched the best possible ways to achieve the highest performance in these areas, at a sensible price. The Azur 540A/ 640A topology uses the same tried and tested output devices that Cambridge Audio have used in previous award winning amplifier models, but many hours of research have gone into the study and development of the preceding stages. This driver dircuitry is essentially à matched differential input pair, loaded by à current mirror and driven from a transient compensated current source driving à high beta cascoded voltage gain stage. The thermally compensated output stage is setup to inherently give optimum Class AB conditions (for greatiy reduced cross over distortion caused by dynamic heating of the output dies). In addition the topology includes a further improvement to the driver stage consisting of à pure class-A follower to isolate the voltage amplifier transistors from the difficult loading of the output transistors. This increased current drive to the output stage combined with a novel transient feed forward circuit doubles the slew rate to 40V/us.

Due to critically refined circuit board layouts, careful component placement and short signal paths the stability of these amplifiers is exremely high which allows the compensation components to be

reduced in size. This has the effect of reducing distortion, increasing dynamics and allowing the bandwidth to be opened up to à massive 80kHz, ideal for the new better than CD' high bandwidth sources such as DVD-Audio and Super Audio CD.

The performance of any amplifieris limited bythe dynamic abilties of its power supply, and for this reason Cambridge Azur amplifiers incorporate many features, including à low flux toroidal transformer, paralleling of the reservoir capacitors and careful use of bypass capacitors, to allow the instantaneous clean delivery of charge whenever it is needed. This ensures an open and natural sound being reproduced and ensures à positive response to any dynamics or sudden transients in the signal being reproduced

Particular attention has also been paid to the quality of the passive components which have been carefully chosen for their sonic benefits. The Azur 640A in addition uses high grade Polypropylene signal bypass capacitors to improve signal flow and dynamics

The Cambridge Audio Azur 540A and 640A amplifiers also incorporate tone controls, which may be switched out of circuit in ‘direct’ mode for the shortest and therefore purest signal path. Other features include 24k gold plated phono sockets, dual tape loops, pre amp output, à headphone socket and à secondary set of high level loudspeaker terminal.

An important feature which has been included as standard on both the 540A and 640A is the new innovative Cambridge Audio designed CAP5 protection system. This consists of a microprocessor which constantly monitors the amplifier providing comprehensive protection against à variety of possible faults. This has been achieved without adding any active circuitry into the signal path to degrade the sound or the dynamic abilties of the amplifier.

Cambridge Audio has built up an extensive knowledge base due to meticulous listening and tweaking. This attention to detail results in amplifiers that are totally convincing in the reproduction of both tonal colour and dynamic contrast, deliver à vibrant and fluid performance with music of all types and are extremely musically invohing.

To get the absolute best from this equipment we would encourage you to use only high quality source components. Of course we particularly recommend tuners and digital equipment from the Cambridge Audio range, all of which have been designed to the same exacting standards as our ampliiers. Many types of loudspeakers were used in the development of these amplifiers to ensure maximum compatibility with à wide variety of designs

Interconnects and speaker cables are also something that shouldn't be overlooked. Please do not compromise your system's performance by using poor quality cables to connect source components to your amplifier or the amplifiers output to your loudspeakers. À system is only as good as its weakest link. For this reason we do not include cheap “reebie" cables with any of our products. Your dealer can supply good quality Cambridge Audio interconnects and Mordaunt Short/Gale loudspeaker cables that will make à noticeable improvement to the sound quality of your system.

Now we invite you to sit back, relax and enjoy!

Matthew Bramble Technical Director

Rear panel connections .

Operating instructions.

SAFETY PRECAUTIONS Checking the power supply rating

For your own safety please read the following instructions carefully before attempting to connect this unit to the mains.

Check that the rear of your unit indicates the correct supply voltage. If your mains supply voltage is different, consult your dealer.

This unit is designed to operate only on the supply voltage and type that is indicated on the rear panel of the unit. Connecting to other power sources may damage the unit.

This equipment must be switched to Standby mode when not in use, unplugged if not used for long periods of time, and must not be used unless correctiy earthed. To reduce the risk of electric shock, do not remove the units cover (or back). There are no user serviceable parts inside. Refer servicing to qualiied service personnel. I the power cord is fitted with a moulded mains plug the unit must not be used if the plastic fuse carrier is not in place. Should you lose the fuse carrier the correct part must be reordered from your Cambridge Audio dealer.

The lightning flash with the arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated “dangerous voltage’ within the products 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.

This product complies with European Low Voltage (73/23/ EEC) and Electromagnetic Compatibility (89/336/ÉEC) 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 qualiied service personnel.

Plug fitting instructions (UK only)

The cord supplied with this appliance is factory fitted with a 13A mains plug fitted with a 3A fuse inside. fitis necessary to change the fuse, itis important that a 3A 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 13A 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 identifyng the terminals in your plug. Connect them as follows:

The wire which is coloured BLUE must be connected to the terminal which is marked GREEN/ Ë

with the letter N' or coloured BLACK YELLOW 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 cor

GREEN GRIP IF your model does not have an earth wire, then disregard this instruction.

If a 13 Amp (BS 1363) plug is used, a 3 Amp fuse must be fitted, or if any other type of plug is used a 3 Amp or 5 Amp fuse must be fitted, either in the plug or adaptor, or on the distribution board.

INSTALLATION Please take a moment to read these notes before installing your amplifier, they will enable you to get the best performance and prolong the life of the product.

The unit requires ventilation above and below. Do not situate it on a rug or other soft surface and do not obstruct the air inlet and outiet grilles on the underside and top cover. Do not place in an enclosed area such as a bookcase or in a cabinet.

This unit must not be exposed to dripping or splashing water or other liquids. No objects filed with liquid, such as vases, shall be placed on the unit. In the event, switch off immediately, disconnect from the mains supply and contact your dealer for advice

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.

Do not route the power cable so that it can be walked upon or damaged by other items near it.

Electronic audio components have a running in period of around à week (if used several hours per day). This will allow the new components to settle dou, the sonic properties will improve over this time.

Itis recommended that when bi-amping, the same type power amplifiers are used.

This amplifier 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). If you do not intend to use this unit for à long period of time, unplug it from the mains socket.

540A/ 640A Integrated amplifier

To clean the unit, wipe its case with à most, lintfree cloth. Do not use any cleaning fluids containing alcohol, ammonia or abrasives. Do not spray an aerosol at or near the amplifier.

These units are not user serviceable, never attempt to repair, disassemble or reconstruct the unit if there seems to be à problem. À serious electric shock could result if this precautionary measure is ignored. In the event of a problem or failure, please contact your dealer.

This unit should be installed on a sturdy, level surface. Due to stray magnetic fields turntables should not be located nearby due to interference.

Once you have completed all connections to the amplifier, plug the AC Power Cable into an appropriate mains socket. The amplifier is now ready for use.

Loudspeaker connections

The 540A and 640A have two sets of Loudspeaker terminals on the rear panel, speakers À and B. Speakers A are the main speaker terminals, speakers B are the secondary switchable speaker terminals. Connect the wires from your left channel loudspeaker to the LEFT + & -terminals, and likewise 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 input. Care should be taken to ensure no stray strands of wire are shorting speaker outputs together. Please

Note: This amplifier has been designed for use with loudspeakers that have à nominal impedance of between 4 and 8 ohms.

Please ensure that the speaker terminals have been tightened adequately to provide a good electrical connection. It is possible for the sound quality to be affected if the screw terminals are loose.

Connect these sockets to the inputs on an external Power Amplifier(s).

These sockets can be connected to a tape deck or to the analog sockets on à MiniDisc or CD recorder. Connect an interconnect cable from the recorder's Line Out sockets to the amplifier's Tape Monitor sockets. This

monitor doubles up as the standard tape/recording medium input.

Note: When connecting a source component that has both an input and output i.e. à tape recorder, the output of which should always be connected to the Tape Mon input. This will eliminate howiround if the wrong input channel is selected.

These sockets can be connected to a tape deck or to the analog sockets on à MiniDisc or CD recorder. Connect an interconnect cable from the Tape Out sockets of this amplifier to the recorder Line In. Please note that this unit has to tape loops which have identical outputs.

CD/Tuner/DVD/AV/ MD input sockets

These inputs are suitable for any line level' source equipment such as CD players, DAB or FM/AM tuners etc.

Aux Phono input sockets

Connect any line level' source equipment to these sockets i.e. CD player or DAB tuner. Alternatively this particular input can be converted to à dedicated tumntable if desired although to do this a Cambridge Audio PMO1 Phono Module must be fitted. Please contact your Cambridge Audio dealer who can supply and install à phono stage to your amplifier.

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.

540A/ 640A Integrated amplifier

If you are connecting a turntable to your amplifier then its ground wire should be attached to this point

CONNECTING 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 configure your system depending on your requirements. The following diagrams are designed to make connection easy.

The following diagram shows the basic connection of your amplifier to à CD player and a pair of loudspeakers.

The following diagram shows how to connect the amplifier to à tape recorder or other source with a record and monitor connection:

Please note that either of the tape loop outputs can be used {as theyare both the same).

Tape / MD Player | |

The azur amplifiers are equipped with PRE-OUT sockets. If your loudspeakers have to sets of terminals then it is possible to bi-amp your system using à further power amplifier. Bramping uses tmo amplifiers to drive the bass and treble units in the loudspeakers independentiy, resulting in even greater clarity coupled with improved control and dynamics. An example of à bi-amp setup is illustrated in the diagram adjacent.

Please note that if using a second azur amplifier as the slave amplifier, any line input can be used to connect from the master's Pre-Out.

Using Speaker B connections

The Speaker B connections on the back of the amplifier allow a second set of speakers to be used, which could be for another room.

540A/ 640A Integrated amplifier

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es es Standby/ On Please note that care should be taken when selecting if two

Switches the unit between Standby mode (indicated by dim power LED) and On (indicated by bright power LED). Standby is à low power mode where the power consumption is less than 10 Watts, The unit should be left in standby when not in use.

Allows for the connection of headphones with a "Jack plug connector. When the headphones are connected the loudspeaker relayis released switching off the output to the loudspeakers (Speakers À and B)

Enables/ disables the secondary set of speaker terminals on the back panel. This can be used for listening to an extra set of speakers in another room.

loudspeakers are going to be used on each channel. If the combined resistance measured on the speaker terminals is too low the amplifier may not suitch out of standby mode until a suitable load resistance is detected. For more information please see section on CAP5 protection system.

Note - When using two pairs of speakers each pair should be rated at least 6 ohms (or higher). 4 ohm speakers are not recommended when using more than one pair.

This control gives the audio signal à more direct path to the power amplifier stage of your amplifier, bypassing the tone control circuits for the purest possible sound quality.

Bass and treble tone controls

These controls allow subtle adjustments to the tonal balance of the sound. In the central position these controls have no effect. These controls only modify the sound through your loudspeakers and the Pre- Out sockets (where featured), 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. If the musical recording is of poor quality and/or the loudspeakers/surroundings are lacking it may be necessary to adjust the tone controls to compensate.

The Volume control increases/ decreases 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

It is advisable to turn the Volume control fully anti-clockwise before switching the amplifier on

This control allows you to adjust the relative output levels of the left and right channels. In the central position the output from each channel is equal. This control only modifies the sound through your loudspeakers and the Pre-Out sockets (where featured), it does not affect the signals sent through the Tape Out connections.

540A/ 640A Integrated amplifier

Input selection push buttons

Push the appropriate input selection button to select the source component that you wish to listen to. 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, although the recorded signal can be checked using the tape input Tape monitor.

Tape monitor selection button

This control lets you listen to the output signal from a tape recorder or signal processor connected to the amplifier Tape monitor sockets. When Tape monitor is selected, the source component chosen by the input selection push buttons continues to be routed to the Tape Out sockets for recording or processing.

Remote control operation/ features

This Amplifier is supplied with à system remote control that operates both this amplifier and the Cambridge Azur CD players. The functions relevant to the amplifier are as follows:

Power - Switches the amplifier between Standby mode and On mode Mute - Mutes the audio (indicated bythe input LED fiashing).

Volume +- - The volume buttons increase and decrease the Volume of the amplifier output.

Input select - The five input select buttons and the Tape monitor select button are used to change the input source.

CAP5 - FIVE WAY PROTECTION SYSTEM Cambridge Audio has developed a proprietry protection system to ensure reliability and long life to its amplifiers. This protection system comprises of five main protection methods:

Intelligent clipping detection

CAP5 has the ability to detect when the amplifier starts to clip or overdrive its output, which can damage Loudspeakers, the amplifier power supply and most importantiy degrade the sound. When CAP5 detects clipping the volume will be automatically nudged doun until CAP5 detects an undistorted* output (*the volume is nudged down until the distortion is less than 2% which listening tests have shoun is difficult to hear).

Itis possible to disable only this feature by holding down the Standby button during power up (whilst plugging the unit into the mains power) The unit will indicate this by flashing the protection LED for several seconds. Disabling the clipping detection is not advised as this feature has been added to protect the amplifier.

Over temperature detection

CAPS includes temperature detection which constantiy monitors the heat generated by the output transistors. When the monitored temperature reaches a high level (suitably within the limits of the output devices) the amplifier will automatically switch into a fault mode (indicated by double flashing of the protection LED). The unit should ideally be left for 15 minutes in this state to cool doun adequately. Ifthe unit has not fully cooled doun 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 à short listening time.

Short circuit detection

During power up from standby or during input channel selection CAP5 performs à check on the Loudspeaker terminals to see if a short across the terminals has been accidentally introduced. 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.

CAP5 offers Loudspeaker protection if the output of the amplifier goes to DC because of some internal fault. This is a rare fault although it could just save those expensive Loudspeakers

Ifthe amplifier is switched out of standby when the input signal to the amplifier is too high {with the current volume setting) the CAP5 system will detect this and reduce the volume to a suitable level

Overvoltage/ overcurrent detection

CAP5 offers V/1 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. Many amplifier designers include V/1 limiting in the

signal path which can degrade the signal by compressing dynamics. The CAP5 system operates outside the signal path and when triggered shuts down the amp rather than limits the size of the signal passing through the amp (signal compression). V/1 protects the amplifier against short circuits on the speaker terminals during use.

540A/ 640A Integrated amplifier

Protection LED flashes for 4 seconds when unit attempts to come out of Standby mode.

CAP5 has detected that the resistance on the Loudspeaker terminals is too low. Check to see if there is a short circuit between the Loudspeaker terminals.

Note: I the indication remains the same and multiple Loudspeakers are being used on each Loudspeaker output then please remove a pair and retry. f too many Loudspeakers are connected to any amplifier causing the Load resistance to drop too low the amplifier will overheat. CAPS will detect this situation.

If the indication remains the same with only one set of loudspeakers connected then there could possibly be a fault with one or both of the loudspeakers.

Unit has suitched off during operation. Protection LED constantly double flashes.

CAP5 has detected a user related fault, the internal temperature of the output transistors has reached the over temperature limit. The unit is not damaged although it should be left for 15 minutes to coo! down before being switched out of standby.

Unit has switched off during operation. Protection LED constantiy flashes on and off in bursts of 4

CAP5 has detected a user related fault, there maybe a short circuit betieen the loudspeaker terminals. Please check all Loudspeaker connections before attempting to switch unit out of standby

Unit has switched off during operation. Protection LED is on with a brief off flash.

CAP5 has detected a fault which requires the unit to be serviced. DC has been detected on the output of the amplifier which could damage the speakers. The amplifier is now unusable. Please switch off and contact dealer.

TROUBLESHOOTING There is no 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

Make sure the unit is not in Standby mode

Check that source component is properly connected

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

If channel LED is flashing tum mute off

There is no sound on one channel

Ensure that balance control is in the correct position Check speaker connections

There is a loud buzz or hum

Check tumtable 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

Will not switch out of standby - protection LED flashing

Please see section on CAP5 protection System

Protection LED flashing Please see section on CAP5 protection system (page 12)

SPECIFICATIONS Power Output

Max Power Consumption

Standby Power Consumption

S to N Ratio (unweighted) Slew Rate (into 8) Dimensions (HxWxD)

LIMITED WARRANTY 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. f 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 retumed 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 à 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 à 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 à

540A/ 640A Integrated amplifier

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.

REPAIRS OR REPLACEMENTS AS PROVIDED UNDER THIS WARRANTY ARE THE EXCLUSIVE REMEDY OF THE CONSUMER. CAMBRIDGE AUDIO SHALL NOT BE LIABLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR BREACH OF ANY EXPRESS OR IMPLIED WARRANTY IN THIS PRODUCT. EXCEPT TO THE EXTENT PROHIBITED BY LAW, THIS WARRANTY IS EXCLUSIVE AND IN LIEU OF ALL OTHER EXPRESS AND IMPLIED WARRANTIES WHATSOEVER INCLUDING, BUT NOT LIMITED TO, THE WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PRACTICAL PURPOSE.

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.

Matthew Bramble Technical Director

(Slew Rate) (an 8W Q)

Matthew Bramble Technical Director

Ground connection (Terre)

Platine cassette / MD | |

Aquës Aguës Si votre amplificateur est équipé de prises PRE-OUT et que vos haut- parleurs possèdent deux séries de bornes, il est alors possible de bi- amplifier votre système à l'aide d'un autre amplificateur de puissance (voir figures 4, 6 & 7). La biampliication utilise deux amplificateurs pour faire passer indépendamment les graves et les aigus dans les haut-parleurs. Ceci permet d'obtenir un son encore mieux défini et d'améliorer les possibilités de réglage et de dynamique du système.

Bi-amplification | |

Please note that if using a second azur amplifier as the slave amplifier, any line input can be used to connect from the master's Pre-Out.

Matthew Bramble Technical Director

Please note that if using a second azur amplifier as the slave amplifier, any line input can be used to connect from the master's Pre-Out.

75 W (in 4 Q) 50 W (in 8 Q)

100 W (in 4 Q) 65 W (in 8 Q)

Matthew Bramble Technical Director

Matthew Bramble Technical Director

Please note that if using a second azur amplifier as the slave amplifier, any line input can be used to connect from the master's Pre-Out.

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