Cambridge Audio AXA25-25 Watt Separate Integrated Stereo Amplifier HiFi System Featuring Tone and Balance Control with Front Aux Input - Lunar Grey

Product Information

Naturally for a receiver, the 85-watt AXR85 has FM/AM tuners, which is bolstered by a built-in Bluetooth receiver, three analogue RCA inputs, a phono stage and a 3.5mm aux input. Recording, subwoofer and 6.3mm headphone outputs are correct and present too. More uniquely at this price, the AXR85 boasts two zones for driving two pairs of speakers simultaneously. Covering the history of Cambridge Audio and the evolution of its budget offerings would serve only to prematurely wear the keys of my already battered keyboard. If you’re interested, I wrote on the subject at length in my AX series summary. If you’re not, the review herein is strictly dedicated to the AXA35 amplifier and will also detail the AXA25. On paper the two amplifiers are very similar with only a 10W jump in output power and specification improvements setting them apart, but in practice they are two very different amplifiers. The AXA25 is a very indirect successor to the A1 and to an extent my A5, whereas the AXA35 is cut from the same cloth as the proceeding Topaz AM10 and the Topaz receivers. Inside the AXA25 you’ll find quality components and short signal paths for the best sound quality in its class. Careful circuit design reduces the signal path, giving higher purity sound and less distortion. Other quality engineering components include a high-spec heat sink that is die-cast rather than pressed steel and a damped power supply – reducing the chance of annoying transformer hum and buzz. Cambridge do not give a spec into a 4Ω load, which is unsurprising given that the power supply isn’t built to drive difficult or low impedance loads. Larger reservoir caps, for example, would have given the AXA35 a significant bump in headroom and a bit more grunt. It’s not uncommon to see 4700UF caps as a minimum on the PSU rails of a DIY-built Gainclone. You could up the voltage too – the LM3886 can handle peak input voltages of +/-94V, and comfortably up to +/-40V with ample cooling, which the AXA35 certainly provides. The AXR100 mostly mirrors its brother's spec sheet, building on it with a 100-watt output as well as twin optical and single coaxial inputs.

I can’t help but feel it could have been better engineered in places too. A bigger power supply would vastly improve the performance of the amplifier, and a better preamp would give the amplifier a chance to show what it is really capable of. Neither are difficult to design, and neither should add significant component cost to the product. If you’re competent in electronics and DIY-minded though, the older AM10 and the AXA35 are perfect candidates to form the basis of a DIY Gainclone. As well as being more powerful, the AXA35 also improves internal component quality, giving improved sonic detail and realism with less distortion. The toroidal power transformer and separate pre/power amp circuit boards are features usually only found in much more expensive amplifiers, making the AXA35 something of a giant-slayer.

Otherwise the amps are functionally similar, broadly speaking. One reviewer referenced past Cambridge amps as having “something of the biscuit tin about them” with “casework that wasn’t what you’d call well-damped”. Neither comment I feel is justified based on my experience with multiple iterations of the A1, the A5, early CD players and the first models in the Azur range. Having said that, the AXA35 arguably sounds clearer and has a more neutral tonal balance, doing more than enough to justify a five-star rating at this price point. It looks and sounds the part, and if this is just a hint of what the rest of the Cambridge Audio’s AX range has to offer, we’re in for a sonic treat. Boasting 35 watts per channel, the AXA35 is 40% more powerful than the smaller AXA25. This not only means it’s better at filling larger rooms but also in delivering a richer, more dynamic sound at lower volumes.

It’s true to say that the new casework is better, but examples of poorly damped biscuit-tin casework are more prevalent in boutique British equipment at several times the price of any Cambridge. Poorly built casework and preschool electronics design aside, some of that gear is ugly enough to offend a blind man’s sense of aestheticism. Placing its tweeter right at the top of the speaker and fitting it within a curved baffle helps enhance the speakers’ sound staging. This means you get a bright, open sound that effortlessly unfurls between the speakers. The Titanium tweeter unit also provides pin-sharp detail while remaining smooth and easy on the ear – the ideal balance. It should be noted though that abusing the tone controls to get more bass out of a low-powered system is not always a good idea. It’s nothing to do with some snobbish view that “it’s not how hi-fi should be heard” blah blah, but because with a 35W amp excessive use of the tone controls at high volume will cause the amp to clip sooner. Clipping, a flattening of the peaks in the audio waveform, is more often than not the cause of blown speakers, not excessive power. Thus you’re more likely to damage your speakers with this amp if you turn the bass to max and crank up the volume than you will if you leave the tone controls flat.

At the heart of the 3020 are new drive units. Starting at the top, the new Ring Dome tweeter provides a more accurate response, for precise reproduction of even the most subtle aspects of music. The tweeter unit is decoupled from the rest of the cabinet, meaning that it isn't affected by vibration from the bass unit. The new Aramid fibre/paper woofer cone is light, rigid, and helps give the 3010s their punchy, agile sound quality. Under the display, there’s a row of four buttons, each corresponding to the relevant analogue input on the rear. A volume dial and menu button are on the right, while a 6.35mm headphone output and 3.5mm auxiliary input sandwich the amp’s infrared receiver on the left. The LM3886 does, however, have inbuilt protection against over and under-voltage, power supply and output short circuits, thermal runaway and instantaneous temperature peaks. They are durable and reliable chips and offer excellent performance comparable to a discrete output stage. Regardless of the amplifier you use you should always consider its limitations in partnering equipment and the environment. I’ve fixed a few AM10s over the years with blown output chips all as a result of driving too heavy a load at too high a volume. If your system is obviously distorting or if you’re running the amp at or near its maximum volume, upgrade to a model with more power. Speaking of the tone controls. They are of the shelving type and cut and boost at 100Hz and 10kHz respectively. They’re not subtle as a result, but as this amp is likely to be paired with smaller bookshelf speakers or less capable floorstanders they will be more useful than controls that adjust the 20Hz and 20kHz frequency extremes. Skilfully engineered, the Cambridge Audio AXC25 puts the emphasis firmly on sound quality. Features such as separate power and output circuit boards and a centrally mounted CD transport help reduce distortion and maximise the potential of the high quality Wolfson DAC (Digital to Analogue Convertor). Features are basic but the sound is certainly a step above its rivals.