Cambridge Audio 540P User Manual

azur 540P/640P

Phono pre-amplifer

User’s manual

The 640P uses more exotic amplification circuitry to provide even lower
distortion and noise plus the higher gain stage for MC cartridges. In
addition, the 640P employs multi-parallel capacitors to achieve
exceptional RIAA accuracy of only 0.3dB up to 50kHz and features a
defeatable subsonic filter.

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

Matthew Bramble
Technical Director

2 Azur phono pre-amplifier

Thank you for purchasing this Cambridge Audio azur series phono pre­amplifier. It is the result of our ongoing research and development
program for 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 phono pre-amplifier

The design of a high quality but cost-effective phono pre-amplifer
presents a major challenge. Providing first-class performance on an
unlimited budget is one matter; achieving the same performance within
tight price limits is quite another, and requires all the expertise and
experience that Cambridge Audio brings to its product design process.
We believe we have succeeded in our aim of creating a first-class
affordable product.

The 540P features a moving magnet stage whilst the 640P offers
moving magnet and moving coil stages. Both use discrete transistors for
the all-important input stages instead of the more common integrated
circuits.

Both are designed to produce high gain and linearity, without requiring
massive amounts of negative feedback to achieve low distortion. These
new models also employ a single-ended ‘Class A’ gain stage with
audiophile passive RIAA equalisation.

High quality components are used throughout such as 1% metal film
resistors and close tolerance polypropylene capacitors.

INTRODUCTION

540P/640P Phono pre-amplifer

Azur phono pre-amplifier 3

Introduction .................................................................................................2

Important safety Information......................................................................3

Rear panel connections..............................................................................4

Troubleshooting......................................................................................... 6

Specifications ............................................................................................6

Limited warranty....................................................................................... 7

CONTENTS

Please take a moment to read these notes before installing your Azur
phono pre-amplifier, they will enable you to get the best performance
and prolong the life of the product. We advise you follow all instructions,
heed all warnings and keep the instructions for future reference.

This unit must not be exposed to dripping or splashing water or other
liquids. No objects filled 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.

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 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.

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

To clean the unit, wipe its case with a moist, lint-free 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 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.

IMPORTANT SAFETY INSTRUCTIONS

4 Azur phono pre-amplifier

MC input sockets (640P only)

If your turntable uses a moving coil cartridge, connect outputs here
(0.5-1mV, with 100 ohm 220pF loading).

MM input sockets

If your turntable uses a moving magnet cartridge, connect outputs here
(3-5mV, with 47k ohm 220pF loading).

Turntable ground

If your turntable has a separate grounding lead then connect here. This
provides shielding to the arm and the sensitive circuitry in the turntable.

Cartridge Type selector switch (640P only)

Match this switch to the cartridge type that your tunrtable uses. MM for
a moving magnet cartridge or MC for a moving coil cartridge.

Subsonic Filter (640P only)

The subsonic filter cuts out very low frequency ‘rumble’, caused by vinyl
imperfections, which can affect your system’s performance.

Output sockets

Use phono cables to connect to any line level input on your amplifier,
such as Aux.

NB. Do not connect to a phono level input.

PSU socket

Once you have completed all connections to the amplifier and turntable,
plug the PSU power cable into an appropriate mains socket. The blue
LED on the front panel will indicate that the power is on. The unit has
been designed to be left permanently powered.

Please note the 640P has an output relay, which after power on takes
15 seconds to come out of mute.

NB. Only use supplied power supply.

REAR PANEL CONNECTIONS

MM

Phono Input

Manufactured in an

ISO9002 approved facility

Designed in London, England

azur 540P

MM Phono Pre-Amplifier

Output

www.cambridge-audio.co.uk

12V

0.5 A

Use supplied PSU only!

RL RL

This device complies with part 15 of FCC rules

Turntable
Ground

RLRL

540P 640P

MM/MC Phono Pre-Amplifier

Use supplied PSU only!

azur 640P

12V

0.5 A

RLRLRL

Designed in London, England

RL RL RL

Output Subsonic Filter Cartridge Type

This device complies with part 15 of FCC rules

On Off MM MC

www.cambridge-audio.co.uk

Manufactured in an

Turntable
Ground

MCMM

ISO9002 approved facility

540P/640P Phono pre-amplifer

Azur phono pre-amplifier 5

From a

turntable

with a

moving

coil

cartridge

using

phono

cable

(2RCA-2RCA)

only one of these

connections

From a
turntable
with a
moving
magnet
cartridge
using
phono
cable
(2RCA-2RCA)

To any line level

input on you

amplifier using

phono cable

(2RCA-2RCA)

Must not be

connected to a

phono level

input

MM

Phono Input

Manufactured in an

ISO9002 approved facility

Designed in London, England

azur 540P

MM Phono Pre-Amplifier

Output

www.cambridge-audio.co.uk

12V

0.5 A

Use supplied PSU only!

RL RL

This device complies with part 15 of FCC rules

Turntable
Ground

RLRL

To any line level

input on you

amplifier using

phono cable

(2RCA-2RCA)

Must not be

connected to a

phono level

input

From a

turntable

with a

moving

magnet

cartridge

using

phono

cable

(2RCA-2RCA)

540P 640P

MM/MC Phono Pre-Amplifier

Use supplied PSU only!

azur 640P

12V

0.5 A

RLRLRL

Designed in London, England

RL RL RL

Output Subsonic Filter Cartridge Type

This device complies with part 15 of FCC rules

On Off MM MC

www.cambridge-audio.co.uk

Manufactured in an

Turntable
Ground

ISO9002 approved facility

MCMM

6 Azur phono pre-amplifier

There is no power

Ensure the AC power cord is connected securely.
Ensure the plug is fully inserted and is switched on.

There is no sound

Make sure the unit is plugged in.
Check that your turntable is properly connected.
Check that your speakers are properly connected.
Check all connections are secure and correct amplifier input is selected.
Ensure correct cartridge type has been selected (MM or MC).

There is no sound on one channel

Check that your speakers are properly connected.
Check all connections are secure.

There is a loud buzz or hum

Check turntable or tone arm for ground and connection
lead fault.
Ensure no connections are loose or defective.
Ensure that your turntable is not too close to the amplifier.

Volume is too loud/quiet

Check cartridge type matches input type. If a MC cartridge
is connected through the MM inputs, volume will be very
quiet (and vica versa). Note that it is possible to obtain
high level MC cartridges which are designed for an MM
input.

TROUBLESHOOTING

540P 640P 640P

(MM) (MC)

Max power consumption 5W 5W 5W

Gain @ 1kHz

39dB 39dB 55dB

Nominal output

300mV 300mV 300mV

Sensitivity for

3.35mV 3.35mV 0.5mV

nominal output

THD 20Hz-20kHz

<0.009% <0.005% <0.002%

RIAA curve accuracy

<+/-0.65dB <+/-0.3dB <+/-0.3dB

25hz-20kHz 20Hz-50kHz 20Hz-50kHz

(subsonic filter off)

Signal to noise ratio

>85dB >86dB >72dB

using Audio Precision RIAA-1
with grounded inputs

Crosstalk @ 20kHz

>76dB >83dB >69dB

Dimensions (HxWxD)
mm

46 x 215 x 133 46 x 215 x 133 46 x 215 x 133

inches

1.8 x 8.5 x 5.2 1.8 x 8.5 x 5.2 1.8 x 8.5 x 5.2

Weight
kg

0.8 0.9 0.9

lbs

1.8 2 2

SPECIFICATIONS

540P/640P Phono pre-amplifer

Azur phono pre-amplifier 7

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.

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.

LIMITED WARRANTY

azur 540P/640P

Part No. AP14509/2

www.cambridge-audio.co.uk