Cambridge Audio 840 Series


My wife, who I affectionately refer to as “the music Anti-Christ” often calls me “He without Brains” when it comes to purchasing audio gear. Our latest interchange of pleasantries began when I announced that I needed a new CD player in the $1500 to $2000 range.  She found one at Costco for considerably less than a hundred bucks and thought I would be very pleased.  “You just don’t get it” I said, to which she replied “Neither will you”.  I think she meant it in so many ways.

High on my list for consideration was the Cambridge Audio 840C, a Redbook CD player that has amassed a bucket-load of great reviews over the past few years.  It’s been called the best CD player under $5000 by some pretty revered ears and invariably punches well above its weight class in nearly every review.  So it seemed a little begging was in order.

The begging paid off in spades………well, at least with respect to getting an 840C for review.  Better yet, my review sample was accompanied by two other highly regarded components from Cambridge Audio’s “8” series, namely their 840W 200 watt power amplifier and the 840E stereo preamplifier.  Even though I’m not in the amp market right now, I thought that this would be a great opportunity to evaluate a fully integrated system representing Cambridge Audio’s latest and greatest efforts.

This company has been shaking things up a lot lately in the audio world by producing some outstanding audio components.  While there is no shortage of companies that routinely do this, what sets Cambridge apart is the fact that their high-end audio equipment is…………..gasp………remarkably affordable.  This combination is extremely rare and welcome since the chasm separating high-end audio and affordable audio is frequently insurmountable for many people.  I could hardly wait to test these reported giant killers in my own listening environment.

Specifications : 840C CD Player

  • Design: Redbook CD Player
  • MFR: 20 Hz – 20 kHz ± 0.1 dB
  • Upsampling: 24 bit 384 kHz
  • THD+N: <0.0005%
  • IM: <0.0002%
  • S/N: 113 dB, A weighted
  • Dimensions: 4.5″ H x 16.9″ W x 14.7″ D
  • Weight: 18.7 Pounds
  • MSRP: $1,799 USA

Specifications : 840E Stereo Preamplifier

  • Design: Stereo Preamplifier
  • MFR: 10 Hz – 100 kHz, + 0.1 dB
  • S/N: < 121 dBr
  • THD+N: < 0.0006%
  • Output Impedence: 100 Ohms (Balanced or Unbalanced)
  • Dimensions: 4.5″ H x 16.9″ W x 15.2″ D
  • Weight: 19.1 Pounds
  • MSRP: $1,799 USA

Specifications : 840W Stereo Power Amplifier

  • Design: Stereo Power Amplifier
  • Power Output: 200 WPC into 8 Ohms; 350 WPC into 4 Ohms; Mono (Bridged) 500 Watts RMS into 8 Ohms
  • MFR: 5 Hz – 80 kHz, – 1 dB
  • THD+N: < 0.005% from 20 Hz – 20 kHz
  • S/N: > 90 dB (Unweighted)
  • Damping Factor: > 125 at 1 kHz
  • Dimensions: 5.8″ H x 16.9″ W x 14.4″ D
  • Weight: 33 Pounds
  • MSRP: $2,699 USA

The Design

840C CD Player

Normally, I’m far more interested in how a component sounds rather than how it was designed, built, and marketed.  However, in this case, Cambridge Audio certainly didn’t leave me with a lack of things to write about.  The 840C is truly a technological marvel, offering up a smorgasbord of interesting and desirable features.  It’s hard to know where to start, but let’s try near the beginning.  CD data at 16 bit/44.1 kHz is upsampled to 24 bit/384 kHz using an Adaptive Time Filtering (ATFTM) process developed by Anagram Technologies of Switzerland.  This process utilizes an advanced interpolation algorithm to generate the additional information between the CD’s data points, providing a number of audible advantages including a pronounced reduction in jitter and error harmonics.  Each channel then has its own 24 bit DAC (Analog Devices AD1955) which is subsequently processed by individual, symmetrical analog filter circuitry. Nyquist theory be damned, upscaling CD data truly offers significant audible benefits.

The 840C not only improves upon the sound of Redbook CDs but you can also utilize the sophisticated DAC circuitry and upscaling capabilities for two additional digital inputs.  Digital sources can be input through either a Toslink optical connector or a S/P DIF coaxial cable.  These additional digital inputs are accepted in a variety of word widths and sampling frequencies, and can either be passed through directly or processed to several other word widths and frequencies.  Overall, the 840C offers a great way to improve the quality of your CDs and other digital sources such as DVD, media servers or IPod docks.  While I reviewed the entire 840 system as a stand-alone unit, it is designed for easy integration into more complex environment through the use of its RS232 port, a Control Bus input/output and an infrared emitter input. I can’t think of any other CD player offering more bang for the buck than the 840C.

Appearance wise, the 840C is pretty much, just straight business.  The thick aluminum face has a minimal number of buttons for essential CD functions with two additional buttons to access and select from the numerous menu options.  A large LCD panel and the well constructed CD tray occupy the center of the unit.  The LCD provides information on track number, upsampling rate, and elapsed or remaining time.  LCD backlighting can be toggled between bright, dim, and off either from the front panel or the remote.  The menu and select buttons allow you to toggle between the two digital inputs or CD playback.  All functions are also controlled by the well designed and hefty remote, which has the additional large benefit of providing amplifier and pre-amplifier control.  I found that the remote from either the CD player or the pre-amp accomplished everything one needed for ordinary listening. Nice, nice, nice.

840E Preamplifier

The 840E is Cambridge’s top of the line stereo pre-amplifier. It accepts a total of seven inputs, including two balanced inputs using XLR connections.  Like the 840C, it has a number of features that allow for easy integration into a multi-room system such as a Control BUS Input/Output, RS232 control, an IR emitter input, and trigger input/output and throughput connections.  The 840E is physically designed similar to the CD player, with a larger central LCD panel indicating the volume level and the input being utilized.  The display can be switched to scroll through other functions such as balance, treble and bass, or direct throughput bypassing the tone controls. All inputs can be named, as desired, and a number of other nice features include the ability to trim the various input levels of different sources to yield common levels of loudness when switching, switching the volume ramping function on and off at start-up/shutdown, and a headphone output.  The 840E can also be directly synched to a matching 840W power amp, a feature which I utilized and loved. For those employing smaller monitor speakers, there is also a sub output which can be run full range or low-passed at 200 Hz.  Both balanced and unbalanced outputs are available at rear.

The heart of the 840E’s audio quality resides in its design, superb build quality and the utilization of a number of novel technologies.  Proprietary Terrapin (10 pin) amplification modules designed by Cambridge are utilized rather than pedestrian op-amps for the low level gain stages.  Precision resistor ladders are utilized for volume and balance controls, rather than common potentiometers.  There is definitely an authoritative feel to volume changes with a pleasing click between each transition as the gold plated relays conduct their business.  Physically, the case is rigidly designed and acoustically damped within, sharing the same thick faceplate with other “8” series components.  Yet none of this would matter if it didn’t sound great………..but it does.

Cambridge Audio 840 Series

840W Power Amplifier

Cambridge designed a new amplification topology for the 840W, referred to as Class XDTM.  Essentially this functions to move the zero crossing transition point of conventional AB designs to a different level, boosting the range of pure class A operation.  Once this is exceeded, the amplifier then switches to an improved class B design.  A white paper provided on Cambridge Audio’s website is very informative regarding the goals and improvements associated with this topology.  Again, build quality is evident throughout from the acoustically dampened, rigid chassis and their choice of 1% tolerance metal-film resistors, gold plated bus bars and polypropylene signal caps. Similar to the other “8” series components, there is outstanding flexibility with the 840W.  This includes a duplication of all the control features (control bus, trigger functions, IR emitter in) available on the 840E and 840C but more impressively, one can run this amplifier in conventional stereo mode, bi-wired stereo mode, bridged mono, and bi-amp mono (provided one is fortunate enough to have two 840Ws).

Overall, it is clear that Cambridge Audio focused on providing an acoustic blitz rather than aesthetic glitz with all components in the Azur “8” series range.  With this mission accomplished, their efforts were then placed on providing tremendous flexibility, convenience, and ready integration into multi-room systems.  Visually, the components speak quality but are unlikely to garner any oohs and aahs until they are turned on.

Cambridge Audio 840 Series


I set up all three components in my 12′ x 18′ listening room and used balanced XLR cables from Bryston for all testing.  Speaker wire was DIY Belden with silver-soldered gold terminations.  I employed three different sets of speakers with this review, including Genesis 750s, KEF 104/2s, and Proac Tablette 2000s.  Each of these speakers has their own sonic personalities and quirks, none are overly expensive, yet they all can sound very pleasing and accurate when properly driven.  The Genesis 750s are far and away the most revealing speakers of this trio so I spent the majority of time with them.

My set-up for this evaluation was pretty much a straight plug-and-play and I was up and running in about 10 minutes. However, based on the advice of others, I let all components burn in for about 150 hours prior to conducting any serious listening. Even though I only utilized the bare essentials of the 840 components, one cannot help but be impressed with the thoughtfulness and versatility incorporated into their design, particularly with respect to their potential for integration into a more complex system. The feature set of each component goes far beyond anything that could be routinely expected at their price points.

I also tried the 840C CD player alone on my reference system comprised of an Anthem AVM30 feeding two Bryston 7B-ST monoblocks that drive Genesis APM-1 speakers.  To my ears, this is a very revealing system that harshly punishes poor components and/or recordings.  It also provides stunning rewards with well recorded music and is quite discriminating and revealing with respect to incorporating any new components.

In Use

One of the many things I love about music is that it can turn me into a blithering idiot. A number of songs grab me emotionally and send shivers up my spine, an effect that’s greatly magnified on a really nice system.  This all started as a kid, when listening to Clarence Carter’s “Patches”, R. Dean Taylor’s “Indiana wants me”, or Wayne Newton’s “Daddy, don’t you walk so fast” on 45’s could bring me close to tears.  I’m not suggesting that these songs will do it for you, and no, I didn’t use any of them for this evaluation, but I’m sure that many of you know what I mean.  My shivery choices for this evaluation were “My beloved wife” from Natalie Merchant’s Tigerlily CD and Elton John’s “Indian Sunset” from the “Madman Across the Water” CD.  Yep, the chills were there.  Both of these artists sing with such passion and emotion in these songs that I’m turned into a sopping floor puddle.  The Cambridge trio captured every subtle crack in Natalie’s voice and perfectly conveyed the sadness and despair in Elton’s tale.  The “chill factor” provided by the Cambridge trio is near the best I have ever heard.

Cambridge Audio 840 Series

Next, I listened to a number of recordings that I’m intimately familiar with and that I know to be well recorded and produced. “Slow body poppin” from Billy Cobham’s Warning CD delivers some gut-slamming bass and searing guitar despite its unassuming title.  Again, perfect instrument placement and pop was delivered to the Genesis.  I kept cranking the dial until I feared for my speakers, but I had no reason to believe that the Cambridge lacked more throttle than I was willing to deliver.  I then moved to Lee Ritenour and Dave Grusin’s Harlequin CD, which was a drug used by many audio shops to hook potential customers back in its day.  The first time I heard the title track, it felt like I was getting repetitive glaucoma tests.  When this didn’t happen with the Cambridge, I was a little disappointed………..until I remembered to take off my glasses.  There it was.  Eye-popping mid bass and Ivan Lins’ stunning vocals, all delivered perfectly through the Genesis.

Cambridge Audio 840 Series

With Frankie Goes to Hollywood’s “Two Tribes”, the soundstage was the largest I have ever heard my KEFs deliver.  They have never performed better and truly disappeared in this massive barrage of sound extending from floor to ceiling and wall to wall.  Here, this song left me giddy with fondness as to how stunningly three dimensional a good two channel set-up can be.  Go Frankie!  Finally, I tried to stay within Cambridge’s Class A volume range with Dire Straits “Love Over Gold” CD and Roger Waters “The Pros and Cons of Hitchhiking” CD using the Proac Tablettes.  Both of these recordings have great depth and imaging, although the latter can be brutally sibilant on lower quality gear.  Pure late night pleasure that sounded as dramatic and vibrant as I’ve heard on systems costing five times this price.  Even though I’ve nearly worn the pits and bits off of these CDs, the Cambridge trio offers them up sounding almost brand new.  Overkill amplification for the Tablettes, to be sure, but they certainly matched well with this system and I’ve never met a speaker that didn’t respond well to high quality signals and amplification.

Cambridge Audio 840 Series

Even after a lot of listening with the Cambridge, it is still really hard to find adjectives and superlatives that truly encapsulate the great qualities of this system.  No matter what I threw in the tray, bass was incredibly well controlled over a wide range of listening volumes, ranging from loud to louder to loudest.  At any sane volume level, there was never a hint that I was approaching the amplifier’s thermal control or clipping limits.  Just tight killer bass.  The separation of instruments and vocals was steadfast throughout and there was a very wide sense of space in all dimensions.  However, it’s my description of the top-end where I know I will fail the most at conveying the true beauty of these components.  It was neither bright nor glaring, but everything is there.  It is certainly not what I would call warm or curtailed, but, but, but……….it revealed new content in recordings that I’ve probably listened to over a hundred times on several dozen different systems.  So let’s go with strident without being harsh, piercing but clean. I don’t exactly know which member of the 840 trio should get the credit, but as a package, this system is an absolute knockout.


Well, I hate appearing to be a sycophant to Cambridge Audio and/or the many reviewers who have evaluated these products previously, but I’m left with little choice. So here goes………….more of the same.  One can hardly overstate what Cambridge Audio has accomplished with their recent 840 series.  Tremendous value, tremendous flexibility, tremendous sound!  I think if these components were suddenly doubled in price, they would be immediately be embraced by the upper crust of high end audio snobs.  The CD player opened a new window on many recordings that I felt I was completely familiar with. The 840E/840W pre-power combination provides an embarrassment of riches with respect to features and flexibility and it does so without gimmickry or garishness.  These components provide superb value at their price points.  Most importantly, they will move you up very high on the stairway to audiophile heaven without requiring a second mortgage.  My nit-picks are so small, they seem meaningless and don’t even warrant mention.  These components merit your serious consideration if you’re climbing the high-end ladder as you’ll ascend remarkably high for a very reasonable price.  It’s easy to recommend any, better yet, all of the 840 series components wholeheartedly and enthusiastically. The CD player is now on my “must-have” list and I’m seriously scheming on how to delay home renovations for an 840E/840W acquisition. This is a sincere audio company that’s doing just about everything right to bring high-end sound to the masses.