Arcam Radia A25 Integrated Amplifier Review

Posted on 26th February, 2024

Arcam Radia A25 Integrated Amplifier Review

Mark Gusew auditions an affordable new integrated from a famous British brand…


Radia A25 Integrated Amplifier

£1,499 RRP

Arcam Radia A25 Integrated Amplifier Review

Last October, Arcam unveiled a range of new products under the Radia banner, targeting a younger demographic with a focus on high quality and affordability. The lineup featured three stereo integrated amplifiers, the A5, A15, and the A25 – which is the primary focus of this review. Of the trio, the A25 boasts the highest specifications, delivering a robust claimed 100W per channel continuous power output into 8 ohms, and 165W into 4 ohm speaker loads. Designed to pair seamlessly with the Arcam CD5 CD player or the recently reviewed ST5 streamer sources, these products share the distinctive Radia styling cues and offer user-friendly operation with shared remote control functionality.

Despite its gutsy onboard power amplification, the A25 is a relatively sleek and space-efficient design, featuring a full-width yet slimline build. Departing from the conventional appearance of amplifiers, Arcam has gone for a more modern look by employing a matte aluminium chassis with vibrant Radia yellow accents and rounded corners. The front panel sports a frosted surface housing a dimmable OLED display and two large rotary dials – one for input selection and the other for volume – with a glowing yellow halo effect. This design aesthetic extends to the remote control, enhancing the overall unique and elegant feel.

Arcam Radia A25 Integrated Amplifier Review

Connectivity options on the A25 include three RCA line level inputs, one TOSLINK and two coaxial digital inputs (24-bit, 192kHz max), and a USB-C port for connectivity to computers, mobile devices, or even a Raspberry Pi, supporting audio up to 32-bit, 384kHz. The inclusion of a high-quality ESS ES9280A Pro DAC enhances the audio experience, Arcam says. The amplifier also accommodates a turntable with a moving magnet cartridge, and has Bluetooth 5.2 with AAC and Qualcomm aptX support for 24-bit HD audio, and a headphone output (3.5mm) on the front panel.

Internally, you'll find the fifth generation of Arcam's Class G power amplifier circuitry. Unlike the commonly used Class AB operating mode of most amplifiers, Class G theoretically offers greater efficiency for a given amount of power, by changing the output stage's supply voltages according to the signal level. This results in less heat buildup and permits the fitment of smaller, lighter heatsinks. It's interesting that this A25 employs this type of circuitry whereas the more affordable A5 and A15 still use Class AB. As you would expect, a large toroidal power transformer is fitted with two sets of filter capacitors, each of which is dedicated to a voltage rail. According to Arcam, carefully selected components have been used; even the design of the rubber ring-tipped feet have received careful attention, the company says.

Arcam Radia A25 Integrated Amplifier Review

The A25 is nice enough to use. It works in an intuitive way, with the two large dials providing a smooth feel; they control input selection and volume control respectively. Inputs can also be renamed. Pushing the volume control wakes up the unit out of standby, and mutes and unmutes the volume. The remote control is required to change settings within the menu and is reasonably comprehensive. Being nicely balanced, it's better than average to use and hold in the hand; although made of plastic, it has a reassuring feel. An optical infra-red design, it has one of the best ranges I've experienced – you can even change the volume when it's pointed at the rear wall or ceiling, rather than directly towards the amplifier.

Getting going is simply a case of connecting a power lead and plugging in your music source(s) and loudspeakers or headphones, and then you're off. I auditioned the A25 with a range of loudspeakers, large and small, but my main listening tests were done via modified JBL HDI-3800s. I primarily used the output of a Holo Audio Red Streamer and Spring 3 DAC into the analogue input of the Arcam.


The A25 has a clean, open and well-balanced sound with the emphasis on rhythmic drive. Tonally, the Arcam is even-handed from top to bottom, with good bass extension, a slightly forward and reasonably articulate midrange, and a smooth treble that is free from any harshness or undue emphasis. Soundstaging is commendable, too, conjuring up a wide recorded acoustic when playing high-quality recordings. Given that this British brand has been making high-quality integrated amplifiers for nearly half a century now, none of the above should come as a surprise.

This amplifier's enjoyably fresh and vibrant sound comes across clearly with good recordings such as No Love to be Found by Michael McDonald. Here, it's possible to enjoy the drummer's work with the kick drum and how it feeds off the bass guitar. The two instruments are well-defined, and you can clearly hear their respective timbre and speed. The snare drum also has good speed and slam but doesn't dominate the mix, which in turn lets the vocals take centre stage. The A25's fine sense of rhythmic drive means that pretty much any genre of music comes off well.

Arcam Radia A25 Integrated Amplifier Review

Tonally, this is a fairly smooth-sounding performer, although the midband is ever so slightly on the forward side, and this adds some pep to the proceedings. You'd never call it harsh or forward, though. Indeed, if anything, the bass is a teensy bit on the thick side, rather than being super spry and dry. Any music you play through this amplifier gets good bass extension, so much so that I think prospective purchasers need to match it to their speakers thoughtfully. For example, the A25 will flatter smaller bookshelf speakers, which could be lacking in very low-frequency weight; this amp should make them sound bigger and fuller.

Soundstaging is satisfyingly broad and wide. For example, Helplessly Hoping by Crosby, Stills & Nash turns out to be a lovely listen. The legendary rock trio's voices are spread left, right and centre, extending well beyond the loudspeakers, letting me really enjoy their famous vocal harmonies. There is a decent sense of front-to-back depth, considering the price of the A25. You don't get high-end levels of dimensionality, as you would expect at this price, yet it's still enjoyable enough.

Arcam Radia A25 Integrated Amplifier Review

This amplifier isn't especially distinguished as far as detailing goes. It tells you a good deal of what's happening on the recording, but you'd never call it forensic. On the other hand, it really impresses with its dynamic capabilities – even more so because the visual design doesn't exude a sense of physicality or power. Playing The Widdler's Lost in Space pt. 2 at high volumes shows how low the bass can go; it's gutsy and strong, while boasting good transient speed. Indeed, it's tough enough to fill my medium-sized listening room with high levels of sound without any sense of compression or distress. And thanks to its efficient Class G design, it doesn't get hot to the touch on the top of the chassis.

Whilst the A25's performance via line inputs is very good, I am happy to say that the internal DAC is no slouch either. I used the output of a Holo Audio Red Streamer directly into the coaxial digital input, and after going back and forth from my external DAC to the internal one, there wasn't much in it. Considering the price point of this amplifier, that's rather impressive. Sure, the more expensive DAC has more soundstage information, superior accuracy, and better instrumental timbre, but what the Arcam delivers is still satisfying and comprehensive.

Arcam Radia A25 Integrated Amplifier Review

This amp compares very well with the Advance Paris A7 I recently reviewed; although they are similar in price, they sound quite different. Using the line input and listening to Royksopp's Here She Comes Again, the latter has a softer yet more expressive bass while the former gives more impact and weight to the bass line. The Advance delivers a more detailed account of everything within the track, while the A25 focuses on the bigger picture, so to speak, with more punch and scale. Both are excellent, and in isolation they satisfy well but in different ways.

I really enjoy the way the onboard phono stage sounds – it is lively, direct, nuanced, balanced and has good instrumental timbre. For this review, I plugged a vintage nineteen seventies AR turntable into the amp's MM input, with a Shure V15 III cartridge. With Diana Krall singing They Can't Take That Away From Me, I clearly preferred the Arcam's sound to a Pro-Ject phono stage that I had to hand. Vocals, in particular, sounded cleaner and more life-like.

This amplifier's headphone output is similarly impressive. Driving a pair of Sony WH-1000XM3 headphones, Now and Forever by Gary Numan

Arcam Radia A25 Integrated Amplifier Review


With the new A25, Arcam has nailed the brief and delivered a highly competent integrated amplifier with broad appeal. The Radia styling enhances its look and feel, and the handy features make using it all the more pleasant. Sonically, the amp has a musically enjoyable character with plenty of power and grunt, which makes it ideal for driving a wide variety of loudspeakers. The overall package delivers higher levels of enjoyment than expected for its price, making it a compelling choice in its category.

For more information visit Arcam

      Mark Gusew's avatar

      Mark Gusew

      Starting his first audio consultancy business in the early 80’s whilst also working professionally in the electronics industry, Mark now manages a boutique audio manufacturer.

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      Tags: arcam 


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