In 2012 Cambridge Audio’s Stream Magic 6 became my first hi-fi streamer, me being at the time a relative newcomer to the world of streaming audio. Later superseded by an upgraded V2 model and soon after the CXN, the Stream Magic 6 was one of the most feature-packed streaming devices on the market at the time with a wealth of connectivity and an extensive list of supported audio services and formats built upon a solid custom streaming platform. The 851N is the latest product to join Cambridge’s product portfolio, designed to partner the flagship 851 series which also includes both integrated and power amplifiers, an analogue preamplifier, a DAC and a CD player. Every product in the range is built to offer uncompromising audio performance, though with practical features that set them apart from the traditional bare-bones designs more commonly found on the market today.
The products in the range all share the same core DNA, and the 851N is no exception. Not only does it share the styling of its 851 siblings including the acoustically damped chassis and thick brushed aluminium panels, it inherits the digital circuitry also found in both the 851C CD player and 851D DAC. Powered by a substantial toroidal transformer feeding an extensively regulated power supply section, at its heart sits a pair of Analogue Devices AD1955 24-bit DAC chips, fed by an Analogue Devices BlackFin ADSP-BF532 32-bit DSP running Cambridge’s proprietary ATF2 (Adaptive Time Filtering) upsampling technology which upsamples all incoming audio to 24-bit, 384kHz.
There’s a host of digital connectivity on the back including optical, coaxial, AES-EBU and XMOS asynchronous USB, supporting resolutions of up to 24-bit, 192kHz and DSD64 along with both balanced XLR and unbalanced RCA outputs. The 851N can also act as a digital preamplifier to directly feed a power amplifier such as the 851W, the volume controlled within the DSP to keep the signal in the digital domain until the last possible moment to achieve the purist possible sound.
On the streaming front, the 851N can stream audio from just about any imaginable source whether it be a USB storage medium connected to one of the 4 USB inputs, a DLNA server on the network or one of the over 20,000 onboard internet radio stations. Spotify connect is onboard too, as is Apple’s AirPlay and aptX Bluetooth, though you’ll require the optional BT100 bluetooth dongle to access the latter. Just about every common audio format is supported including FLAC, WAV, MP3, WMA, ALAC, AAC, AIFF, M4A, HE AAC, AAC+, OGG and DSD64. M3u, ASX and WPS playlists are supported too.
The unit can be controlled via its front panel, the included 851 series remote control or via the Cambridge connect app for both iOS and Android. Information is displayed on a 4.3” (11CM) colour display, which is also used to display album artwork.
Packaged similarly to the rest of the range, the 851N certainly offers a luxurious first impression, wrapped in cloth and supported by large foam inserts. The packaging even includes a pair of offset handles to facilitate shifting the boxes around, a thoughtful touch that all but Cambridge sadly seem to omit.
It’s supplied with some quick start documentation, an 851 system remote control with included AAA batteries, a control bus RCA cable and a USB wifi antenna. Finding the BT100 Bluetooth dongle included in the box would’ve been a welcome addition, though with higher quality sources available I’d imagine it’s an omission that few will miss.
At 8.1KG the 851n is no lightweight, much of that no doubt thanks to the substantial casework. A 3/4” slab of aluminium forms the front panel, with brushed aluminium wrap-around side panels and a top plate featuring a pair of trapezoidal grilles for ventilation. The unit sits on 4 heavily damped feet, with further ventilation on the bottom. I’ve always liked the styling of the 851 series components, and the exceptional build quality leaves nothing to be desired.
The display takes centre stage on the front, flanked by neat rows of push button controls and a large dial that doubles up as both a means of navigating the streamer’s interface, and a volume control for use in digital preamp mode. The dial is the same weighty aluminium control as found on the 851A, 851E and 851D, fronting a smooth digital encoder which despite a little play feels substantial and makes navigating the 851N’s user interface simple and speedy.
To the left a power button and LED are accompanied by home, info, ‘more’ and filter controls, the latter toggling between 3 subtle digital filters provided by the ATF system, and also offering the ability to reverse the phase of the outputs. There’s also an IR sensor, a front USB jack for connection of USB storage media and some LEDs to show the current filter and phase setting.
To the right of the display sit a set of transport controls including play / pause, stop / delete, previous and next. A return control is inset into the front panel for use when navigating the 851N’s menu system.
There’s a lot more going on around the back, beginning with analogue outputs in both balanced XLR and unbalanced RCA form, and digital outputs in optical, coaxial and AES/EBU form to send the 851N’s digital signal to another DAC if desired. On the input side, there are 2 optical, 2 coaxial and AES/EBU XLR inputs, along with the asynchronous USB computer input with a ground lift switch designed to reduce hum if present. The 851N supports USB audio class 1 and 2, the latter offering support for higher resolutions but requiring that Windows users download a free driver from the Cambridge Audio website. Mac OS users need no such driver, and can stream 192kHz audio through the USB input out of the box. Resolutions of up to 96kHz are supported in class 1 mode.
An ethernet jack offers the option of wired network connectivity, and there’s an RS-232 port for use in custom installations as well as the control bus connections to allow the 851N to control, and be controlled by, other Cambridge Audio equipment. There’s also an IR jack for connection to an external IR repeater for use in situations where access to the front panel IR sensor is blocked. The front panel IR sensor can be disabled entirely in the streamer’s settings if desired.
3 USB inputs cater for external storage media with a maximum current draw of 1A available for each. One of those USB inputs doubles up as the connection for the wireless antenna, and Cambridge warn in the manual that only this input must be used and that the antenna should not be connected or disconnected with the unit’s power on. Speaking of power, a grounded IEC power socket and a power switch rounds out the rear connectivity.
The supplied remote control (model RC-8/SM) is identical to that supplied with the newer 851 series components and is a joy to use. It’s of a decent weight and well balanced, with a logical control layout and integrated backlighting that can be enabled at the push of a button. The central controls including those for navigation and volume are large and slightly raised making them easy to distinguish, and also emit a gentle click when pressed. The remaining controls are of the small, round, rubber dome variety yet feel just as good, and cater for everything you could possibly need including navigation and transport controls, display brightness and control of a matching amplifier.
The remote follows the RC5 standard, so it’s likely that it may control other components in your system too. To that end, the remote, and the 851N itself, can be configured to use an alternative set of IR codes to prevent commands clashing with other units. Power is provided by 3 AAA batteries slotted into the rear compartment.
The 851N can be operated entirely via its front panel or remote, or via the Cambridge Connect app available for both iOS and Android. Though the app is by far the best way to control the streamer, and for accessibility and convenience reasons I opted to control the streamer almost exclusively via the app during the review. The large display means that for most users, interfacing directly with the streamer is not an unwelcome proposition. The screenshots below were taken with the app running on an iPhone 6.
Getting connected couldn’t be simpler, thanks to the 851N’s support for Apple’s AirPlay wireless setup. Using an iOS device, the 851N can be configured as any traditional AirPlay speaker, whereby the wifi settings from your device are securely copied to the streamer simply by tapping on the device name in the wifi settings page of an iOS device on the same network. I had the 851N up and running on the network within seconds of it powering on for the first time. Of course, you can enter your network details directly on the streamer itself, using the navigation dial or the remote to enter the letters of your network key on an onscreen keyboard. Ethernet connection is fully automatic, and the 851N supports both DHCP and manual connection types.
Once online the 851N will default to its home screen offering access to your local libraries, internet radio, or the streamer’s inputs and settings.
The libraries page shows a list of local USB storage media as well as UPNP servers and, in the case of the app, your local on-device library. It’s worth noting however that on iOS at least, streaming content directly from a device requires that the device remain unlocked and the app remain in the foreground, which quickly depletes the battery, not to mention renders your device useless for anything other than streaming audio.
The 851N does not scan local storage media to build a database of tracks, so it’s recommended to place tracks in artist / album folders to make locating tracks easier. This may seem a little unintuitive at first, but it’s actually a far simpler solution than than many competing products and means there’s no waiting for the 851N to rebuild its database each time a new storage device is connected. I was able to use both a USB 3.0 hard drive and a flash drive simultaneously, the hard drive connected to the rear of the 851N and the flash drive connected to the front panel USB input.
Radio stations can be filtered by location, genre, codec or bitrate. Choosing filters presents a list of stations according to your chosen criteria, the below screenshot showing just some of the stations in the united kingdom of which there are a great many.
There’s a search function that works exactly as you’d expect, and access to your stored presets.
When a track or station is playing, pressing the info button toggles between several modes that alter the information displayed on the 851N’s front panel display. These include a Combination of track/stream info plus album/station art, album/station art only, or track/stream info only. Album art and station logos are fully supported, though the 851N does not support images embedded within tracks. For USB media, album art must be in the same folder as the track and in either the .png or .jpg format. The files can be of any name, though folder.jpg or folder.png will take precedence.
When playing Internet Radio, pressing the ‘More’ button displays options related to the station currently playing such as alternative stream types, content types or similar stations. When playing from a local library, pressing this button will display the queue and its related options, at which point the navigation controls can be used to jump directly to a specific track in the queue or to remove or reorder the queued items. The queue function is much like a typical playlist, whereby individual tracks and even entire albums can be placed and reordered within the queue. If the network standby mode is enabled the 851N will remember the current queue when the unit is in standby.
Selecting an individual track from a local library will present 5 options. Play from here adds the entire album or playlist to the queue, though playback begins with the selected track rather than at the start of the album or playlist. Play now stops the current track, plays the selected track and then reverts to the previous queue. Play next places the track in the queue immediately after the currently playing track. Add to queue appends the track to the end of the existing queue, and replace queue replaces the current queue with the selected track. The 851N does support gapless playback.
The 851N offers a page of configuration settings, accessed via the respective tab on the home screen. The display brightness, device name, USB audio class, remote IR code set and digital preamp mode can all be configured, the latter enabling a balance control for use when the 851N is operating as a preamplifier. You also get the ability to customise the names of the digital inputs, check for a firmware update, restore the unit to factory settings and configure the auto power down and standby mode. In network standby mode, all network circuitry remains active when the unit is in standby, allowing the unit to be powered on / off via the CA connect app. In eco mode, all audio, network and control circuits are shut down, reducing the power output but meaning that the 851N must be powered on via the front panel or via the remote control. The auto power down function sets the unit to standby after a user-configurable period of inactivity, 30 minutes by default.
The 851N also offers a web-based configuration page, accessed by typing the IP address of your unit into a web browser when it is connected to a network. here you can configure the network settings, change the device name, initiate a firmware upgrade, add custom presets via the stream URL and link and unlink streaming accounts. You can also choose to install beta firmware updates via this page.
The settings available via the app are somewhat limited, though you do get a couple of view options and the ability to set the control bus mode, which governs the modulated IR commands that will be sent out of the 851N’s control bus outputs to your amplifier or AV receiver. You can also enable the ability to stream content from your device, and disable the sleep function of your smartphone or tablet when the app is running.
It’s hard to describe the character of the 851N’s sound, especially when that character makes it so listenable. Taking review notes is the last thing on your mind when your library of high-res Beatles reissues begins to play. In fact I struggle to determine whether the 851N does indeed have a character of its own at all, so neutral and true to the source material is its presentation.
Firstly, there’s a distinct lack of background noise, music emerging from an inky black background, or in the case of the Beatles reissues, the glorious hiss of the analogue tape. And then there’s the 851N’s ability to retrieve a truly unfathomable amount of detail from a track, unmatched by many a piece of high-end audio esoterica. Soaring vocal crescendos and sublime musical collages are laid before you in a sound stage extending seemingly beyond infinite boundaries. The experience of a full scale orchestra played via an 851N is something to behold, the soaring strings so vivid they’ll raise the hairs on the back of your neck.
I’m often asked how the 851N compares to the CXN. While the 2 are very similar (which if anything is a huge compliment to the CXN), the 851N is a more refined and detailed listen. It’s also possible to tailor the sound of the 851N to your personal taste using the 3 digital filters, though I found the difference to be extremely subtle and couldn’t reliably tell the difference between them.
The 851N is without doubt one of the most feature rich streamers on the market, featuring an abundance of digital connectivity and support for a vast array of streaming services, based on a stable and reliable platform running the best software in the business. And if that weren’t enough, the 851N is a high-end DAC and digital preamplifier too, with many useful, logical features as is so often the case with a Cambridge Audio component.
Not only that but its sound is utterly breathtaking. Its sound puts many high-end streamers and DACs to shame. With features beyond what any player at any price can offer, and a sound that is a cut above the best, it’s hard to imagine why your search for a streamer would lead you to anything else. Highly recommended.