Contents, Introduction | Cambridge Audio 840A V2 guide

Contents
Important safety instructions	..........................................................2
Limited warranty	3
Contents	4
Introduction	4
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

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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.

Class XD Technology International Patent Pending Cambridge Audio Ltd.

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.

Introduction

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.

The 840A V2 features our unique proprietary amplifier topology; Class XD™, designed to eliminate crossover distortion at low signal levels.

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.

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 website: www.cambridge-audio.com

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.

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.

Matthew Bramble,

Cambridge Audio Technical Director and the Amplifier design team

840A V2 specifications

The Cambridge Audio 840A V2 is a high-end integrated amplifier that stands out in the realm of audio equipment, delivering both exceptional sound quality and sophisticated design. This amplifier embodies the brand's philosophy of providing a genuine listening experience that captures the essence of music.

One of the key features of the 840A V2 is its Class XD amplification technology. This unique design combines the best aspects of Class A and Class AB amplification, allowing for low distortion while maintaining high efficiency. This ensures that the amplifier can deliver potent power to drive a wide range of speakers without compromising on audio fidelity. The Class XD design allows the amplifier to operate in Class A mode at low power levels, delivering warmth and detail, while switching to Class AB at higher power levels for greater efficiency and headroom.

The 840A V2 boasts a robust construction that not only enhances durability but also minimizes resonance and vibration, contributing to cleaner sound reproduction. With a meticulous attention to detail, the amplifier features a symmetrical layout, which aids in reducing unwanted noise and crosstalk. The use of premium components throughout the signal path ensures that the audio remains true to the source.

One of the most appealing aspects of the 840A V2 is its extensive connectivity options. It includes multiple RCA inputs, a dedicated phono stage for vinyl enthusiasts, and balanced XLR inputs, making it versatile enough to accommodate various audio sources. The headphone output is powered by a dedicated circuit, ensuring that headphone listening experiences are equally exquisite.

Additionally, the 840A V2 incorporates a high-quality remote control that allows users to conveniently adjust volume levels and switch between sources from a distance. The front panel features a clear display and intuitive controls which makes operating the amplifier straightforward, even for those who might be new to high-fidelity audio equipment.

In summary, the Cambridge Audio 840A V2 integrated amplifier is an exemplary piece of audio engineering. With its Class XD technology, premium build quality, versatile connectivity, and user-friendly design, it offers audiophiles and casual listeners alike the opportunity to experience their music in an immersive and dynamic way. Whether paired with high-end speakers or used in a modest setup, the 840A V2 delivers a performance that reflects Cambridge Audio’s commitment to sound excellence.