Cambridge Audio Edge A Integrated Amplifier Review
Cambridge Audio is the kind of company that has a love of music at its very core. In their own words:
Everything we do is driven by our love of music. We genuinely believe that great things happen when people who love music make audio products.
Although lots of companies make similar statements, the interactions that I've had with Cambridge Audio team and by getting to know their products over the last month or so, I get a sense that they truly stand by it. The Cambridge Audio website has a collage of the employees of the company, along with their favourite music and direct Spotify links. See here.
Cambridge Audio's Edge series was conceived to be bit special, and quite different from previous creations. It's a celebration, a culmination of 50 years of producing great audio products and steadily improving as time passes.
With some three years of development and nine dedicated engineers, the Edge series' products are aimed at the higher end market, with significantly greater production costs and greater expectations.
The Edge range consists of three products including the Edge NQ streaming preamplifier, the Edge W power amplifier, and the Edge A integrated amplifier, the subject of this review.
Incidentally, the Edge series is fittingly named after Professor Gordon Edge, one of the founders of Cambridge Audio some 50 years ago and the inventor of Cambridge Audio's first product, the P40 integrated amplifier.
Leading up to the company's 50th anniversary, the engineers were asked that if the usual constraints of time and money were taken away, what could they come up with that they could be proud of, personally?
Forget cost, forget limitations - create a system that delivers undiscovered layers of detail, is highly transparent, and offers superlative sound-staging. The Edge series is the result. Bravo to the brilliant outside of the box thinking that has produced such a fresh product.
The Cambridge Audio Edge A retails in Australia for $7,995 and enters a market saturated by me-too products that tend to look much the same, and in some cases, more or less sound much the same too. But this amplifier and indeed the range look different, better, fresher. With rounded sides, a clamshell top and exposed heatsinks, the aesthetic is exceptionally stylish and elegant. The way that the amplifier seems to sit on its belly is reminiscent of Thunderbird 2. It's certainly not dull.
The front panel is surprisingly understated and straightforward but does everything needed of it. The main dial is dual concentric and an engineering work of genius. The volume dial is as expected, but behind it is a knurled dial that selects the input options. Operation is smooth and jewel-like, and it works particularly well and is refreshingly simple. Made from some 31 machine-tooled components, the dial is made in England and adds to the minimalist feel of the products.
What you can't see behind the knobs is effectively a fly-by-wire control system. The volume control is monitored by an MCU, which then selects the correct path through an IC resistor ladder for the required volume level, rather than a traditional potentiometer. The selector's position is also monitored by an MCU that decides which input relay to switch. These relays are situated at the rear of the amplifier on the input board, close up to the connectors where they should be situated.
The only other button on the front panel is a small on/off push button and a 6.35mm headphone socket.
The back panel of the Edge A consists of the following line-level inputs: a single Balanced and two RCA inputs. As the integrated amplifier has an inbuilt DAC, digital inputs include a single Coax S/PDIF, two TOSLINK, one USB (class 2), one HDMI Audio Return Channel (ARC) and wireless Bluetooth.
The outputs include a pair of Balanced and RCA pre-outs as well as a single set of good quality speaker multi-way binding posts. A small switch allows for a 20 minute Auto Power Down function, trigger inputs, and an RS-232-C serial port.
The amplifier is solid, beautifully finished and comes exceptionally well packaged. A weighty aluminium remote control is supplied with a handy central mute button and four programmable pre-sets, that remembers your specific pre-set input and volume level. Very handy for switching quickly between your frequently used inputs.
At 24.4kg this integrated amplifier is weighty and suggests that its capabilities may be high. Much of the weight is made up by using two large toroidal transformers. The twin toroidal disks are placed back to back in an opposing symmetry configuration. What is the effect of this arrangement? The result is that far less electromagnetic radiation interferes with the sensitive input stage of the amplifier.
Cambridge Audio engineers also apply a silicon steel screen tape around each transformer to reduce stray magnetic fields, and any that is left is cancelled out by the opposing arrangement. Cambridge Audio says the effect works at all volume levels because each transformer is delivering the same current, so they are in harmony cancelling out each other's electromagnetic field throughout the whole power range. Brilliant!
The amplifier is a class XA design, which I incorrectly assumed is simply a high bias class AB design. In traditional class AB amps, the crossover distortion happens each time the signal crosses the zero level. With class XA, the crossover point is shifted away from zero, and thus crossover distortion only happens for signals larger than a given threshold, which is around 3W for the Edge A.
Nick Brown - Engineering Project Manager at Cambridge Audio, explains:
In practical terms, class XA consists of a tuned constant current generator added to the power stage. This extra current shifts the crossover point away from 0V. Distortion is much more detectable by human ear at low sound levels, while 3W can generate a discrete amount of sound pressure to “hide” crossover distortion.
Also, at normal listening levels, Class XA can be over 200% more efficient than a high-biased class AB yet can deliver the same class A power.
I asked Nick what they did to give the amplifier its characteristic sound?
A lot of listening and auditioning of different components took place during the development of Edge. We adopt a 'listen first, measure later' approach here at Cambridge Audio. Every component in the Edge Series has been selected for its sonic merit through blind auditions - not price, specs nor measurement. We also pushed our engineering boundaries to keep the signal path as short as possible across the series.
So how does it sound?
Let me say straight up, quite incredible, and the result of many intelligent component selections and listening tests mentioned above, I'm sure. The tonal balance of the Edge A is exceptional. It is close to perfect in my opinion, with a smooth, extended, non-fatiguing treble, a natural and neutral midrange and a lovely fast and well-extended bass, with just the right amount of weight and fullness.
The bass goes as deep as any integrated amplifier that I've ever heard, and it does so in a natural manner. There's no annoying thumping or artificial bloat. The soundstage is huge and detailed, exhibiting incredible three-dimensional spatial imaging. The retrieval of detail, depth and clarity are outstanding. Are you following?
Bon Jovi's ”Wanted Dead or Alive”, while coming in a little bright, it's quickly forgiven as the tune really kicks. In years of listening to this track, I hadn't previously heard the air that's apparent around the vocals and acoustic guitar. It's the kind of track that needs to be heard at louder listening levels, and the Edge A had no trouble accommodating my need, which I have to admit is a forte of the amplifier.
It's capable of playing loudly and clean, with no signs of stress or compression. While rated at 100w/ch into 8 ohms, independent testing has confirmed that this is a highly conservative rating by the factory, which other manufacturers would have likely rated at something closer to 140w/ch.
I loved how even this amount of output doesn't convey the amount of push, dynamic expression and slam that is available. It sounds more powerful than some 250w/ch amplifiers I'm familiar with.
“Uptight Downtown” by La Roux starts quietly and then erupts with drums and bassline. The Edge A has an animated delivery, with an enthusiasm that draws you into the beat and quickly gets your foot tapping. Backgrounds are super quiet, and the sound seems to appear from nowhere with excellent articulation and definition.
Pink Floyd's ”Time” from the remastered “The Dark Side Of The Moon” album is a track that plays to many of the strengths of the Edge A, including the inbuilt DAC. The track ebbs and weaves throughout with its quieter moments and rather explosive moments, the Edge A responding to each with confidence. With the volume already turned up for the ticking clocks, I jumped in my seat as the alarms cut loose. Yet, it was crystal clear, with a vibrancy and immediacy that I wasn't expecting to be as intense.
Cambridge Audio's Edge A gets to work by producing sound with real enthusiasm and vigour. There is a swagger and sway in the track with the interaction of bass, drums, synths and guitars that make the track just so enjoyable. The Edge A delivers the combination of the musician's efforts in a way that allows the listener to hear and understand the track a little better, even if you already know the track very well.
Listening to John Mayer sing “Assassin” his voice sounds full, clean and with richness and tonal harmony. He comes across very natural, and his vocal inflections and emotions are delivered so nicely. The track is also noteworthy for the snappy snare drum and deep bass riffs that work so well through the track. The bass digs deep and the amplifier has no trouble with bass control or extension, regardless of the difficulty.
“Sticky Fingers” (Remastered Edition) may not be my favourite track by the Rolling Stones album of the same name, but it undeniably proves what great musicians they are and it's the musicality of this track that really stands out to me. I'm sure that they had fun recording the track and indeed the whole album because it comes across that way. There is air and space around each instrument, along with clarity and distinction.
“Can't You Hear Me Knocking” from the same Rolling Stones album highlighted the way the Edge A can convey subtle dynamic contrasts. If you listen carefully every hit on the snare is subtly different, it's Charlie Watts playing, not a machine and you can hear it. Same for the guitars, there are small inflections and variances that this amplifier allows you to hear clearly. Kudos to Keith Richards and Mick Taylor as you bask in their inexplicable talent captured on the album. To me, that is the definition of musicality; it is human, it conveys emotion, it's what we listen for.
“Live Your Life” by Eric Morillo, Eddie Thoneick & Shawnee Taylor is a dance-worthy track with some nice bass weight and tight rhythms. I'm currently listening to this track through the excellent new Revel F228be loudspeakers with the Beryllium tweeters and it really boogies. The balance is fantastic, and the Edge A can go deep, not with the typical 50-80hz peak but cleanly all the way down to impossibly low depths.
Turning it up it's clear that unlike some amps, the Cambridge Audio Edge A doesn't become overwhelmed or distressed at louder levels. It doesn't sound artificially compressed but just gets louder. This is generally the result of a well-designed power supply that is easily able to cope, and in this case, there is certainly enough power available to suit most folks with normal hearing.
I found the Bluetooth connection to be especially useful and of outstanding quality. In the past, it's been a poor sounding relative to wired connections, but with the addition of the AptX HD codec, any modern portable device also equipped with AptX HD can stream directly to the Edge A with confidence. The range is around 20 meters, and it sounds fantastic. Tonally, it is very similar to a wired connection but with what I suspect to be about 80-90% of the spatial information. So unless you are doing some comparison testing or deep subjective listening, Bluetooth is more than good enough for everyday listening.
One of the underlying strengths of Cambridge Audio's Edge A is the amount of emotion that comes across. It is never sterile, staid or boring. Instead, it's just so communicative. It gets your attention and then commands that you stay and listen and enjoy what is being played - you're drawn to the music.
My memories are still fond of the Cambridge Audio DacMagic that was released back in 1996, and it's hard to believe that it was that long ago. Perhaps I'm showing my age. To my mind, Cambridge Audio has always represented great value and produces products that punch well above their weight. Cambridge Audio's Edge A is no exception.
The simplicity of styling and operation are outstanding and fresh in a copy-cat kind of world. It is a well thought out package and is in step with modern needs. But it's the sound quality that really has me excited. It delivers sound the way that I prefer, with enthusiasm, youthfulness, dynamic expression and musicality that only genuinely great products deliver. It's fun to listen to and begged me to keep playing a little longer.
With 50 solid years under its belt, Cambridge Audio is a company firmly set on remaining here for another 50. It will take precisely this type of 'outside of the box' thinking to draw new customers their way.
The Edge A is excellent value for money, and I dare say there's not a better sounding integrated amplifier at the asking price. I tried to find one but couldn't, and that's why I'm buying the review sample for myself: a well-deserved Applause Award recipient and an unquestionable recommendation.
Oh, and to the staff at Cambridge Audio, thanks for the playlist!
For more information, visit Cambridge Audio.
Starting his first audio consultancy business in the early ’80s whilst also working professionally in the electronics industry, Mark now splits his time between professional reviewing and AV consultancy.