cambridge audio azur 851 series featrure

Cambridge Audio AZUR 851A Review – Simple, direct, and Extraordinary British Sound

Cambridge Audio power amplifier products with traditional British blood have always attracted many music lovers with their simple design and natural British sound. The new Cambridge Audio Azur 851A continues the conventional design of Cambridge Audio, and the sound quality is very British.

cambridge audio azur a

Speaking of Cambridge Audio, many people are familiar with it. Cambridge Audio has a long history as a traditional British audio brand. With its simple and stylish design, its mellow and natural sound has attracted countless music lovers.

Cambridge’s power amplifier products or CD players, DAC decoders, etc., always have extremely excellent sound performance. The traditional British voice has an elegant vocal charm, soft and sweet, delicate sound quality, and has an exceptional British style. As a long-established audio brand in the UK, Cambridge Audio has been praised by many audio enthusiasts for its stylish and simple appearance design, delicate and soft vocal performance, and unique sound restoration capabilities.

cambridge audio azur 851 series feature

Refreshing Design

This time we are introducing Cambridge Audio’s new power amplifier – Azur 851A combined power amplifier. The appearance of Azur 851A still maintains the minimalism that Cambridge Audio has always been. The cabinet is made of metal, and the interior uses an ultra-sturdy structure. The overall look is stable and dignified. Azur851A uses a large LED screen to display the power amplifier’s operating status, which is intuitive and easy to learn.

From the front, the Azur 851A’s panel design is clean and tidy, and the function keys are arranged in an orderly manner. From left to right, there are buttons such as power switch, earphone input, A/B switch, treble/bass adjustment, pass-through mode, and volume adjustment. The overall visual gives people a sense of relaxation and pleasure. It is worth noting that the design of the top surface of Azur 851A is very convenient, with a large area of ​​heat dissipation holes distributed on the top surface, which can effectively dissipate heat during the use of the machine and ensure the stability of operation.

cambridge audio azur a front panel

Azur 851A has many interfaces on the back, including an analog RCA interface and a balanced interface. There are two sets of speaker outputs A and B on the back, which can be connected to two sets of speakers simultaneously, and you can interactively experience different tones. The balanced interface of Azur 851A has dramatically improved the machine grade. Generally, the balanced interface only appears in high-end models. The sound reproduction obtained by using the balanced interface connection method is also more direct and pure.

cambridge audio azur 851a back panel

Technical Characteristics

Cambridge’s products have always welcomed the favor of audio enthusiasts with their high-cost performance advantages. Azur 851A, as Cambridge’s middle-class power amplifier, even has the characteristics of the Hi-End power amplifier in performance. The output power is 120W (8Ω), which is enough to drive various speakers, and the sound performance is natural and real.

Cambridge has always insisted on using toroidal transformers. According to Cambridge, toroidal transformers have better sound performance. In addition to being an integrated amplifier, Azur 851A can also be used as a preamp. The panel is also equipped with a headphone jack so that the Azur851A can also be used with ear amplifiers, so you don’t have to worry about disturbing others when listening to music late at night.

cambridge audio azur 851   toroidal transformer

Azur 851A is equipped with CAP5 protection technology, which can provide necessary protection in many situations, such as the current protection device, which can prevent the amplifier from being damaged by low speaker impedance. Temperature protection can avoid damage caused by poor heat dissipation. Besides, there is direct current monitoring to prevent short circuit problems caused by incorrect connection. The Azur 851A cabinet is made of all-aluminum alloy, which not only provides a good isolation effect but also avoids problems such as vibration.


1) Built-in exclusive XD class high-fidelity audio amplifier circuit, effectively eliminate crossover distortion. The output power is as high as 120W x 2 (8Ω load) and 200W x 2 (4Ω load), enough to drive large speakers.

2) The fully-balanced progressive volume control technology, which is precisely adjusted by 1dB, accurately maintains the balance of the left and right channels.

3) The front stage has an independent toroidal transformer to prevent noise interference.

4) The latter stage uses a large-capacity toroidal transformer, and the left and right channels are each equipped with stand-alone rectification and filter capacitors to provide sufficient energy.

cambridge-audio-azur-851-a circuit

5) The unique radiator enhances the heat dissipation efficiency of the power tube and prolongs its lifespan. Simultaneously, it creates a shielding and isolation effect for the special transformer of the subsequent stage.

6) Heavyweight all-metal cabinet, the panel is made of thick aluminum. The large screen provides clear operating information. 851A provides RCA and XLR balanced input sockets to take advantage of different equipment.

Sound Performance

In terms of timbre, in our impression, Cambridge Audio gives me a feeling of balance, delicateness, and mellowness. After years of experience and improvement, what kind of high-quality performance will this Azur851A have? With the continuous development of the audio industry, high-quality power amplifiers will be inseparable from traditional CD players or digital audio players. The reasonable price of Azur851A is also one of the reasons that attract many audio enthusiasts.

The song “Scarborough fair,” touches the heart. One of the most famous and successful folk songs of the 20th century, “Scarborough Fair,” was used as an episode of the 40th Oscar-winning film “The Graduate.” The tune is poignant, giving people a real touch. The guitar accompaniment version of Scarborough Fair played at this moment has extremely rich high-frequency performance and a sense of dynamics. It is most suitable for testing the mid-to-high frequency of the equipment.

Scarborough fair

At this time, the performance of Azur 851A is affectionate and moving, and there is no sense of powerlessness. The playing intensity of the whole song is balanced. The details are apparent and full of emotion. The vibrato and dynamics of the guitar are distinguishable. The sound is crisp and loud, clean and fast, and the guitar chords are rich as if playing right in front of my eyes.

Test the control and low-frequency performance of the Azur851A with a piece of powerful drum music. They are performed by “Ondekoza.” “Ondekoza” includes traditional percussion drums as the main instrument, and its performance is full of pure folk music and the mysterious atmosphere of the ancient Japanese nation. A variety of drums of different types, sizes, heights, and timbres make a thrilling sound.


The restoration of Azur 851A simulates the stage scene quite wonderfully. The drum beats fall, and the drum sound is real. The low-frequency dive is deep and powerful. The interwoven percussion of multiple drums is not chaotic and exciting. In the interpretation of the whole song, Azur 851A’s low-frequency control is worthy of appreciation. It appropriately grasps the power and sense of speed of this song. There is no exaggerated sense of volume at all, and it feels just right.

The song “El Condor Pasa” is full of extraordinary expressiveness. This song has no lyrics, although only a few short chants, it genuinely shows the singer’s love for this land. The song is full of passion, which tests the control ability of the equipment.

El Condor Pasa

The first thing that Azur 851A presents is its powerful and thick sound field, with a strong sense of energy, which fully expresses the singer’s mellow, thick and penetrating voice. The high-frequency quality is excellent, without any harshness or sound breaking, bright and pleasant. The intermediate frequency is full and charming, and the description is detailed and accurate. There is a good sense of sound density, and the spirit of sound infiltrating the soul.

The vocal performance of Azur 851A is well controlled in terms of emotion. In the interpretation of the whole song, Azur851A’s low-frequency control is worthy of appreciation. It appropriately grasps the power and speed of this song. There is no exaggerated sense of volume at all, and it feels just right. Cambridge Audio Azur 851A, in terms of low-frequency performance, the speed is steady, not fast or slow, and the sense of volume is abundant, which is rare.

cambridge audio azur 851 A / 851 N


The sound of the Azur851A is rich and full. The voice is brisk, bright, and natural. Sufficient sense of dynamics, ample energy, and easy control, under its simple and stylish appearance, its price is appropriate, and the quality is high.