ARCAM Radia Series Overview
In 1972, two Cambridge University students with a passion and curiosity to reproduce music in a new way got together and designed an integrated amp called the A&R A60. Features like a toroidal transformer, large reservoir capacitors, a great output stage with high-powered transistors, and short circuit paths for the most reliable and consistent audio performance were the key ingredients to their design. Their goal was to sell 50 of these to their friends and family. However, by the early 1980s, they had outpaced their goal of 50 units sold by about 31,950! That’s correct; they had sold around 32,000 units worldwide to their fast-growing fanbase.
Fast forward to 2023, and that original A60 integrated amp is the main ancestor of most modern ARCAM products today. In fact, John Dawson, the original co-founder of ARCAM, still visits their offices weekly to share his passion and vision with the entire team. ARCAM is now paying tribute to the original A60 with a brand new lineup called their Radia Series. The new collection is comprised of the A5, A15, and A25 Integrated Amps, the CD5 CD Player, and the ST5 high-resolution streamer.
Our team visited The Vinyl Factory in London, where ARCAM announced its fresh new branding strategy to lead its product development and design into the future. The new branding is centered around great sound, British heritage, and making luxury accessible. The bright yellow lights and circles all over the floor and ceiling of the event made it clear that they are really leaning into the new world of design and audio, and we couldn’t be more excited!
ARCAM provided us with some of the first units from their upcoming Radia Series, allowing us an exclusive early look to evaluate their performance thoroughly. To start, we'll delve into each unit's unique features and technology, helping you decide which one might be the right fit for you. Afterward, we'll share our firsthand experiences and observations from our testing sessions.
Design & Build Quality
ARCAM has done significant research into determining what users ultimately want regarding the design and interface of one of these units. The guiding principle they were after was simplicity. They didn’t want any of these units to be intimidating in terms of their looks, setup, and, ultimately, how you interact with them on a daily basis.
The Radia series exudes a new, clean, and refreshed look. Each unit has a black frosted glass front panel with the ARCAM logo towards the bottom in the middle of the unit. Behind that frosted glass is a hidden display screen that indicates the input, volume level, and other settings. And what’s neat is that when you turn the unit off, the display completely disappears behind the glass, and you would never even know it existed. We found that in the settings, you can turn this off even when using one of the units if you want a truly clean stealth mode look.
The front panels of the amplifiers sport a minimalist design, featuring just two rotary encoders for adjusting volume, selecting inputs, and performing essential functions. ARCAM has cleverly integrated its new signature yellow accent color, using a thin yellow circle encircling the knobs on the A5/A15 and a more subtle addition of yellow on the knobs of the A25. Meanwhile, the CD player incorporates a power button accented with a yellow circle and minimalistic black buttons for essential controls. In contrast, the ST5 streamer has a buttonless and knobless interface, showcasing the elegant black frosted glass front display that seamlessly blends into the rest of your system.
ARCAM didn’t stop at just the front panel. The aluminum body is a deep black color with beautiful wavy lines on the top of the chassis. These add motion to their design and, to us, give it a more modern look. On the sides, a thin yellow line leads to the back of the unit, furthering the new subtle yellow accent branding. On the amps, there is another touch of yellow on the top of the chassis, which is open to the inside of the unit for airflow.
At first, we were a little hesitant about all the yellow used on these, as we feel some people may find it does not match their decor or personal taste. However, after spending more time with them, the branding and design grew on us, and it felt like any of these units would fit in with just about any modern decor. We have to give props to ARCAM for pushing the boundaries in design and not making an unattractive box that you’re hesitant to be proud to display in your room.
In addition, they’ve gone as far as to add a cowl to the back of each unit that slightly overhangs the edges. It not only adds to the beautiful design but also serves a purpose to slightly hide your wires hanging out of the back of the unit. ARCAM also hid all of the antennas in this section, so you don’t see them at all. Details like this make a product design go from good to great. It’s clear ARCAM has heavily invested in learning what users want from their products regarding sound and design.
Features & Technology
All of these new integrated amps are the latest in over 45 years of amplifier design and manufacturing since the original A60 amp came out. Every component and material has been reviewed and analyzed to be sure they excel at their core competence, which is amplification. We’ll first review a few features the amps share, then break down what makes each unit unique.
Check out our ARCAM Home Theater Receivers & Processors Overview
Bluetooth 5.2 with aptX™Adaptive Technology
ARCAM has spent significant resources discovering what users want from their music listening experience. Ultimately, this research led them to what users find to be the most important to them: simplicity. With that in mind, they designed each of these amps to get up and running quickly and easily, right out of the box, without any additional accessories or setup. To make this possible, they’ve included 2-way Bluetooth 5.2 with aptX Adaptive Technology in each unit.
This makes it extremely easy to connect to your amp and provides you with 24-bit HD audio without adding additional pieces of gear to your setup. And because it is 2-way, you can easily connect Bluetooth headphones to your amp for a private or late-night listening session.
If you’re a hardcore audiophile like many of us here at Audio Advice, you may simply look past this feature and want to add on their ST5 streamer, which we will discuss later. But more and more people building an audio system may not necessarily be looking for the absolute highest quality playback. Instead, they want a well-built, amazing-sounding unit that is simple to use and ready to go right out of the box. We must applaud ARCAM for focusing on and including high-quality Bluetooth in the new Radia Series Integrated Amps.
Moving Magnet Phono Stage
For the last ten years, turntable sales in the US have increased every single year. ARCAM understands the resurgence in vinyl is here to stay, so they’ve paid particular attention to the built-in phono stage on each integrated amp unit. We are huge turntable geeks at Audio Advice, so this is a must-have for us, and we were happy ARCAM included it so we can rock out to our favorite vinyl tracks.
Learn more about Audio Advice’s Favorite Turntables Under $1,000
I/O
When you spin around each integrated amp, you’ll see the power switch, power inlet, USB-A port for service, ethernet port, IR in port, trigger in and out ports, optical digital in, two RCA digital in’s, three RCA analog inputs, your phono stage input, preamp output, and your four speaker terminals.
The A25 also includes a USB-C input to plug in your laptop or your new iPhone 15, which uses a USB-C port instead of a lightning port. This input is super cool because you can get hi-res audio above what the Bluetooth on board or even that additional ST5 streamer is capable of. This feature intrigued us because many people who have a dedicated tablet or laptop in their listening rooms would like to plug directly into the unit to get the best sound possible and not have to worry about a potentially unstable WiFi network. If your WiFi goes down or you live off the grid, you can still play hi-res songs saved to your phone or laptop with this USB-C connection.
In addition, they all come with a compact and simplistic remote with all the most commonly used buttons on it.
Every ARCAM Radia unit comes in plastic-free packaging, so it is easy to dispose of natural materials after unboxing.
ARCAM A5 Integrated Amp
The ARCAM A5 Integrated Amp will be the perfect option for those who love intimate music listening with smaller-sized bookshelf speakers. The A5 provides 50W per channel at 8 ohms with Class AB amplification. Inside, you have a high-quality 24-bit/192kHz ESS ES9018 DAC.
ARCAM A15 Integrated Amp
Stepping up to the A15, you’ll get similar features but more power. The A15 provides 80W per channel at 8 ohms with Class AB discrete amplification. It has a larger heatsink and power supply inside the unit, making it a bit taller than the A5. This amplifier topology will allow it to power low-impedance loads with ease. The rest of the A15 is the same as the A5. If you want more dynamic sound and need to power tower speakers in a larger room, the A15 will be a better choice than the A5.
ARCAM A25 Integrated Amp
Finally, the flagship integrated amp in the Radia Series is the A25. The A25 steps it up in almost every department, making it stand out as the best-sounding unit in the lineup by a mile. Providing 100W per channel at 8 ohms with Class G amplification, the A25 gives you incredible dynamics and sound quality.
The Class AB design in the A5 and A15 is a common amplifier technology solution. However, it typically suffers from crossover distortion at low levels. Think about the first time you heard your favorite song on a really nice audio setup. You probably noticed all the small, often quieter, details in the song that a lesser-quality setup wouldn’t reveal. The true magic behind superb audio reproduction isn’t the loud parts but rather those minute details that come alive and make you experience the music on a whole new level. This is where Class G amplification comes in as a clever solution.
What exactly is Class G amplification? Class G inside the A25 uses dual wingdings, which enables it to be pure Class A up to 15W with zero crossover distortion. Then, when it needs more power, it will cross over to Class AB. This makes it a very efficient design as the additional power is only used when required and can switch instantly with virtually zero lag.
ARCAM has been constantly developing and improving its Class G amps for years. The Class G amp inside the A25 is their fifth and newest generation, so you can be sure you have the best-sounding ARCAM Class G amp on the market.
What exactly is Class G amplification? Class G inside the A25 uses dual wingdings, which enables it to be pure Class A up to 15W with zero crossover distortion. Then, when it needs more power, it will cross over to Class AB. This makes it a very efficient design as the additional power is only used when required and can switch instantly with virtually zero lag. ARCAM has been constantly developing and improving its Class G amps for years. The Class G amp inside the A25 is their fifth and newest generation, so you can be sure you have the best-sounding ARCAM Class G amp on the market.
In addition, they’ve also included an ESS ES9280A PRO DAC, a significant improvement from the A5/A15 DACs. The higher quality DAC, larger power supply, and Class G amplifier design in the A25 make it far superior to its smaller counterparts and is for someone who wants the absolute best sound from their system.
As mentioned, the A25 also includes the USB-C input on the back for hi-res audio connections. And the speaker connections are much beefier and higher quality, too. They’ve also updated the screen behind the frosted black glass on the front to be an OLED screen with a higher resolution. Instead of the yellow circle around the encoders on each side of the front panel, they’ve made each knob illuminate yellow, giving it a more luxurious look.
See Audioholics Arcam A25 Integrated Amplifier Bench Test Results
ARCAM CD5 CD Player
Previously, we mentioned how vinyl is growing faster than ever in the audio world. There is a sense of pride and romance when it comes to owning your physical media and exploring your collection in your room rather than staring at a screen. Today, we still see many people who have extensive CD collections, and it’s their preferred method of listening to music. ARCAM has designed the CD5 to be a high-quality CD player that integrates seamlessly with any integrated amp in the Radia Series.
It sports the same 24-bit/192kHz ESS ES9018 DAC as the A5/A15 units and is capable of CD, CD-R, and CD-RW playback. In addition, it plays hi-res FLAC and WAV-encoded CDs and USB files.
On the back, it has RCA analog outs, a coax digital out, an optical out, and a USB-A port to plug in your hard drive and playback USB files.
ARCAM ST5 Music Streamer
The ST5 music streamer is a high-resolution upgrade to any Radia Integrated amp. You simply connect the ST5 to your network, place it under the amp, and connect the two up, and you’re ready to stream 24-bit/192kHz high-resolution audio. Like the CD5, it sports the same DAC as the A5/A15. The ST5 supports Airplay, Chromecast, Spotify Connect, Tidal Connect, Amazon Music, Qobuz, and is Roon Ready.
A nice feature of the ST5 is that it has inter-product communications, which means when you pair it with any of the Radia Series amplifiers, it will act seamlessly as one product. So when you start streaming to your ST5, it’ll wake your amp up from standby and automatically switch to the streamer input. In addition, this enables you to change the volume on your phone while streaming to the ST5, and it will send a signal to the amplifier to make the changes, which gives you analog volume control for the best sound quality.
To go with the ST5, ARCAM has developed a brand new app. And just like everything ARCAM does, they dug deep into research and development, learning how people use apps and used their learnings to make the most intuitive and beautiful app they could. And they knocked this app out of the park! As you can imagine, at Audio Advice, we have used hundreds of different product apps, some good some bad. When an app is bad, it can ruin the entire experience of a product that relies on it. The new Radia app was just a joy to use. It uses a low-level Bluetooth signal to detect the ST5 and walks you through the setup process to get it on your network. Sometimes, this setup process is dreadful and can cause a headache. ARCAM took the pain away from the setup process and made it a pleasant and easy experience.
To get hi-res music, the app has Amazon Music and Qobuz built-in so that you can control your music right from the app. You can also browse radio and podcast catalogs right in the app. ARCAM knows that many people will still use their favorite music apps since that is what they know and love and use Airplay or Chromecast or other options to play on the ST5. For this reason, they kept the Radia app simple instead of trying to jam in multiple services and features that are rarely used and only make it more challenging to use.
Performance
We paired up the A5 and A15 integrated amps with a pair of JBL HDI-1600 bookshelf speakers, which proved to be a great match. Because we see many people using Bluetooth with these units, we decided first to pair up our iPhone using Bluetooth and then add on the ST5 streamer to see how much of a difference it makes.
The first cut we tested on Qobuz was the lively and infectious track from legendary Tom Petty, Don’t Do Me Like That. This track has vibrant guitar and drum elements that will get your toes tapping when played on a quality system. Paired with the A5 and A15, Tom’s vocals were remarkably smooth and warm. The guitar riffs were exceptionally clear, while the drums were dynamic and lifelike. Overall, we were presented with a wide soundstage and an enjoyable experience with both units, even when streaming through Bluetooth.
We then connected the ST5 streamer to the A5 and A15 and used the app to get it on our network. We could then stream in hi-res via Qobuz and test out the same Tom Petty track. If you are a critical listener, you will hear the minor differences when playing back certain songs via Bluetooth vs network streaming. The higher-resolution versions of Tom Petty’s music had a larger sense of depth and wider soundstage with more details in each instrument. However, if you want to use your A5 or A15 for some casual music listening and want the most straightforward possible setup and streamlined system, we were impressed with the Bluetooth on board both units. While we typically recommend getting the highest quality you can get, you have our permission to save some money and use Bluetooth instead of adding on the ST5 streamer. Or simply use that extra money on some higher-quality speakers or basic acoustic panels for your room!
If you can’t decide if you should get the ST5, our team of experts can analyze your use case and listening style and help you determine what is best for you!
When it came down to comparing the A5 and the A15 against each other, since they have the same internal components besides the power supply, it was pretty straightforward. They both have the same sound signature, but the A15 gave us more power and volume, and depending on your speakers, you may need that extra power. If you need help deciding if you need the power in the A15 vs the A5, chat with our team to ensure you get the right one for your system.
Moving up to the A25 integrated amp, we were excited to test the Glass G amp inside. The larger power supply and much more efficient Class G amp put this model in a league of its own compared to its younger counterparts. It brought out much more detail, even when using Bluetooth. And adding on the ST5 music streamer was a match made in heaven. The looks, the ease of connection, the ease of controls, and everything else made us adore this little stack. We paired it with the JBL HDI-3600 floorstanding speakers and played the same Tom Petty track along with various other music in many genres.
As discussed earlier, the advantages of Class G stand out here and are a big jump in overall sound quality. Vocals and instruments sound much more lifelike and invite you into music. Every minor nuance is conveyed with authenticity and precision, which is truly exceptional for an integrated amp at this price point. With the ST5 streamer added on, hi-res music can really stretch its wings and show you the difference between Bluetooth and network streaming quality. For this reason, we recommend adding the ST5 streamer to your system if you go with the A25 integrated amp, as it will allow the A25 to live up to its fullest potential.
However, if you really want hi-res music and don’t want to shell out the extra cash for the ST5 streamer, ARCAM does give you the USB-C input option on the back. We could plug this directly into our computer and get high-res music from the Qobuz app. So, if you have a setup where you know you will plug in your iPhone 15, laptop, or tablet, this is a really excellent option, and we were thrilled to see ARCAM include this!
One point to keep in mind is that if you do use the ST5 or CD5 with the A25, the A25 has much better internal components, so it will be essential to plug the ST5 or CD5 into the “digital in” section of the A25. This way, the streamer will decode the music coming in but let the A25 do the rest of the work since it is much more powerful.
When using the ST5 or CD5 with the A5 or A15, you should use the analog into the amps. This way, the streamer and CD player will use their internal components and allow the amps to focus on the amplification only. And since ARCAM has included inter-product communications, you only have to use the streamer remote to control the entire system.
We also put the CD5 CD Player to the test and added it to our A25 integrated amp. The CD tray was made of a plastic material but was well built and an overall solid unit. Again, it matches the aesthetic of the rest of the Radia Series and allows you to play your CD collection with ease. And the addition of the USB input to playback songs from a hard drive or USB stick is a nice feature they’ve added to this unit. It was a relatively simple setup to plug in our USB stick and play those hi-res songs directly from it with ease.
Overall Recommendation
ARCAM's latest Radia Series stands shoulder to shoulder with some formidable competitors in the market. It's no secret that the audio industry boasts an array of outstanding solutions for music enthusiasts. Nevertheless, ARCAM has consistently demonstrated its commitment to excellence in every product they create. The new Radia Series is a testament to this dedication, offering stunning aesthetics and unparalleled audio quality.
Our evaluation revealed little to fault in these units, a testament to ARCAM's meticulous research and attention to customer preferences, resulting in products that are not only enjoyable but also user-friendly. We would have loved to see the USB-C feature on the A5 and A15 to get hi-res audio without adding on the ST5 streamer, but again, many people will probably use Bluetooth, like ARCAMs research says.
We’re here to help!
If you have more questions about the ARCAM Radia Series or any other audio or video gear, reach out to our team of experts or stop by one of our award-winning showrooms, and we‘d be happy to help you!
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