Contents, Introduction | Cambridge Audio 651A specification

Contents
Introduction	2
Important safety instructions	3
Limited warranty	4
Rear panel connections	5
Connections	6
Front panel controls	9
Apple device compatibility	10
Remote control	10
Custom installation (C.I.) use	11
CAP5: Five-way protection system	11
Technical speciﬁcations	12
Troubleshooting	12

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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.

Introduction

Thank you for purchasing this 651A Ampliﬁer. We are conﬁdent that you will enjoy many years of listening pleasure from it. Like all Cambridge Audio products the 651A adheres to our three core principles – stunning performance, ease of use and incredible value.

Developed as part of our on-going research and development regime, including extensive listening tests, we have incorporated many subtle tweaks and improvements to our circuits, components and layouts in the pursuit of our passion for sound quality.

Very high quality components are used throughout including an Alps volume pot, polypropylene signal capacitors, gold-plated speaker outputs, custom-made electrolytic capacitors in critical positions and several new circuit tweaks. The ampliﬁer is a completely discrete bipolar transistor- based circuit honed over many years powered from a bespoke audiophile-grade toroidal transformer.

Also featured is an environmentally friendly low power (<1W) standby circuit. This circuit completely powers down the ampliﬁer circuits in Standby mode yet is itself totally isolated when the ampliﬁer is on, thus having no effect on sound quality.

All this proprietary engineering is housed within our low resonance, acoustically damped chassis. An Azur Navigator remote control is also provided, giving full remote control of your ampliﬁer in an attractive and easy to use handset.

Remember your 651A 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 source components from the Cambridge Audio Azur range which includes CD players, BD/DVD/SACD/ DVD players, iPod docks and Network players which 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.

Thanks 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 651A design team

651A specifications

Cambridge Audio’s 651A integrated amplifier stands as a testament to the company's dedication to providing high-quality audio performance. Designed to deliver a rich sound experience, this amplifier combines technology and craftsmanship, making it a favorite among audiophiles and casual listeners alike.

One of the key features of the 651A is its Class AB amplification design. This technology ensures that the amplifier produces a warm and dynamic sound, with plenty of detail and clarity. The output power of 75 watts per channel at 8 ohms makes it capable of driving a wide range of speakers, providing impressive dynamic range without distortion.

The 651A is equipped with a high-quality digital-to-analog converter (DAC), which enhances the audio signal from various sources, including digital music players and computers. This DAC is especially beneficial for users who want to enjoy superior sound quality from their digital library. The amplifier also includes multiple inputs, such as five line-level connections and a dedicated phono stage for turntables, allowing users to connect their favorite sources with ease.

Cambridge Audio’s 651A features a comprehensive power supply designed to deliver steady and clean power to the amplifier. This is crucial for maintaining audio integrity, especially during demanding musical passages. The heavy-duty toroidal transformer plays a vital role in this aspect, providing efficient power distribution for optimum performance.

In terms of build quality, the 651A boasts a robust and stylish chassis that not only enhances its aesthetic appeal but also minimizes vibration and interference. The intuitive front-panel design includes a large volume knob and source selection buttons, making it easy to navigate through various inputs.

Additionally, the 651A incorporates advanced technology such as the proprietary Cambridge Audio Adaptive EQ. This feature allows the amplifier to optimize sound quality based on your listening environment, ensuring that you always enjoy the best possible audio experience.

Overall, the Cambridge Audio 651A integrated amplifier combines high-quality components with advanced technology, resulting in a product that offers remarkable sound performance and versatility. Whether you’re enjoying classic vinyl records or streaming the latest digital hits, the 651A provides an immersive listening experience that stands out in the crowded audio market. This amplifier exemplifies Cambridge Audio's commitment to innovation and quality, making it a top choice for those seeking both performance and reliability in their audio setup.