Up to 37% in savings when you subscribe to hi-fi+

Begin typing your search above and press return to search. Press Esc to cancel.

Primare I25 Prisma integrated amplifier

Primare I25 Prisma integrated amplifier

A few issues ago (Issue 163 to be specific), I was wowed by the excellent I35 from Primare. We deliberately chose the denuded version (without its clever Prisma media renderer platform) because we wanted to see how good the amp is on its own, without being clouded by the prism of Prisma. So, we have waited until the newer, smaller I25 emerged, so we can tick three boxes at once – how the I25 performs in and of itself, how it compares to the I35, and how Prisma works.

Short answer, all three boxes are firmly ticked, and ticked well!

Let’s work in that order. The Primare I25 amplifier platform is a 100W integrated design, featuring the companies own UFPD 2 amplifier modules, an updated version of Primare’s original ‘all-analogue Class D’ UFPD module. And let’s stop almost immediately: there’s a sort of myth in audio that the ‘D’ in ‘Class D’ stands for ‘digital’. Class D refers to using the amplifying devices as high-speed switches instead of linear-gain devices as in Class A or Class AB amplifier designs. The confusion comes from the fact that Class D amplifiers create an audio signal by passing a pulse-width modulation output waveform through a low pass filter, “and PWM is digital, therefore… digital!” However, there is no analogue-to-digital or digital-to-analogue conversion taking place within these UFPD 2 amplifier modules. None at all. And yet, the ‘D for digital’ meme hangs around the industry like a fart in a camper van. I suspect it’s because at least some of the ‘D for digital’ carney barkers are finding a convenient if functionally meaningless sound-bite to universally bash Class D, without the inconvenience of having to listen to any amplifiers first!

, Primare I25 Prisma integrated amplifier

On its own, the I25 features five line-level inputs and two outputs, alongside some sync/trigger and RS232 inputs for multi-room use. That’s a good starting place, but things quickly escalate.

There are two upgrade modules, which can – and in most cases, ‘will’ – be fitted in the factory as the I25 rolls off the line, or as after-sale plug-in modules. The first is the DAC module, which adds USB and S/PDIF connections (mostly Toslink) and sports an AKM AK4497 converter chip. The second (which requires the DAC module to also be in place), is the Prisma module, and it is where things get really interesting.

Prisma is the digital streaming platform common to Primare products. It runs on a Google Chromecast backbone, but is pretty much platform agnostic; you can connect it via Ethernet to a local network and/or the internet (it talks to UPnP devices in the home and to systems like Spotify Connect or Tidal out there in the big wide world). Chromecast also makes the I25 Roon-chummy.


Here’s where things get a bit ranty again. The Prisma part of the deal invites some tough questions about the way other brands get music into their system. Basically, unless you are trying to send digital audio via semaphore or smoke signals, Prisma will cope. End of discussion and no qualification needed. Which kind of makes those discussions that take the “well, it doesn’t do X because we think Y” line of reasoning sound like excuse creation. I get it when licenses are involved, and I get it when it comes to digital formats (a product might end up down a sonic wrong turns as a result of opting to support a specific and rare format), but when it comes to acquiring music from a range of places, if the system can’t do it, it’s the system’s fault.

Staying in rant mode for a moment or two longer, some of this is simply ‘not invented here’ syndrome. Chromecast is a fully developed platform that works extremely well. There are more people at Google working on obscure bits of back-office code on Chromecast than there are members of staff in most high-end audio companies. And yet, we frequently re-invent the digital wheel either because of reluctance to pay Google (or similar) its pound of flesh, or the even less comprehensible notion that ‘well, we know better’. While it’s good to have that design and entrepreneurial zeal, sometimes it pays to just use the thing that actually works.

That’s what Prisma does – it works!

Here’s how it works. On the one hand, you have Google Home. This is either an app that came with your Android or Google device, or it’s an app you download from Apple’s app store. Then you download Primare’s app. If your I25 is wired into a network, you get the three to handshake. If the I25 is on a wireless network, you need to set the Wi-Fi password on the I25. If you don’t have a Tidal, Spotify Connect, Deezer, or Qobuz account… get any one (or all) of them. You might also want to consider using Roon in a ‘one app to rule them all’ way (but without any orcs or eyes of fire in the sky). If you have a tablet or a smartphone, the I25 Prisma will turn that into your musical home almost overnight. If you don’t have a tablet or a smartphone, there’s this whole thing called the 21st Century you should try… you might like it!

, Primare I25 Prisma integrated amplifier

Operationally, the Primare I25 Prisma has that understated Nordic design down to a tee. Unlike its bigger brother, there’s just the one dial and three small buttons, with a central monochrome display. This display can be somewhat small when dealing with track replay on a display that is less than 2cm tall across a room, but that’s what apps are for, in which case it can be turned to just a larger volume display! The amp comes with an elegant all-black remote handset, and two stubby aerials for the rear panel. The first box ticked.

Sonically it’s extremely good. There’s a clarity, openness, and extension to the top end that is reminiscent of more expensive audio equipment, and is the antithesis of the notion of ‘digital sound’; this is clean and extended, but not hard-edged or bright, unless you push it beyond its limits. At the other end of the frequency range, the bass is excellent, having both a healthy weight to it and a good sense of beat. This seems independent of input, so if you play ‘Something Better Change’ by The Stranglers [No More Heroes, United Artists], all that raw energy comes across evenly whether it’s a ripped CD stored locally or played via Tidal. Jean-Jacques Burnel bass lines are always crisp and here they came across as being a little thinner than usual, but they aren’t the deepest bass lines around, and they still had some fierce energy behind them.

Stereo separation, in particular, was very good, with the music sitting in three-dimensional space between and slightly forward of the loudspeakers. There was also some layering and depth to the image, giving something of a ‘third row of the stalls’ feel to the image, especially with classical music.

The dynamic range of the I25 also sets a high standard to beat for the price. It’s full of energy, although not to the point of running away with itself. There is always a sense of control and order to the sound of the I25, but within that control, there’s a lot of dynamic energy, both in terms of the big orchestral swells and the ability to pick out fine musical nuances in a piece of music. This makes Joyce DiDonato’s voice on the Stella di Napoli compilation [Erato] both beguiling and compelling, as it has almost weapons-grade force at times and yet subtlety that can move you to tears. Box two… ticked.


Finally, we come to comparing the I25 Prisma with the base I35. The I35 is better sounding, but in many cases, ‘better’ just means ‘more power and control’. Comparing the two side-by-side, the I25 is slightly thinner sounding and the I35’s even greater capacity for ‘oomph’ wins out. But, it’s a close-run thing, and in the context of smaller loudspeakers played at normal listening levels, the differences get a bit nuanced. Ultimately, if I had £3,200 burning a hole in my pocket and only £3,200, I’d go with the I25 Prisma over the base I35. If I knew that £3,200 could grow into a full I35, I’d go for the bigger model. The interesting part about Prisma is if that growth was not immediate, I’d go with the Prisma-equipped I25 over its bigger brother. That’s how important Prisma is, and with that comes the ticking off the last box.

, Primare I25 Prisma integrated amplifier

Make no mistake, products like the Primare I25 Prisma are the best expression of why this is a golden age for audio. This one box does it all, and it does it all damn well!


  • Type: Integrated amplifier with optional internal streamer and DAC
  • Power output: 2 × 100W into 8 Ohms, 2x 200W into 4 Ohms
  • Analogue Inputs: 5 × unbalanced (RCA) stereo inputs
  • Digital inputs: 2x RCA digital inputs, 4x Toslink (up to 24/192), 1x USB A, 1x USB-B up to 768kHz/32 bit; DSD 256/11.2MHz, 2x Ethernet RJ45, 2x WiFi antennas
  • Line level Output: 2 × unbalanced variable (RCA)
  • Digital output: 1x RCA
  • Multiroom connectivity: IR 3.5mm jack, 12v 3.5mm jack, RS232
  • Prisma’s Audio formats supported: WAV, LPCM, AIFF, FLAC, ALAC, WMA, OGG: Up to 192kHz/24bit MP3, MP4 (AAC): Up to 48kHz/16bits, VBR & CBR 320kbps, DSD: Up to DSD128 (5.6MHz)
  • Streaming: Airplay, Bluetooth, Chromecast built-in, Spotify Connect, DLNA/UPnP
  • Frequency response: 20Hz–20kHz -0.2dB
  • Signal-to-noise ratio: > 100dB
  • THD+N: < 0.05%, 20Hz–20kHz, 10W at 8Ω
  • Finish: black or titanium
  • Dimensions (H×W×D): 10.6 × 43 × 42cm
  • Weight: 11kg
  • Price: £3,200

Manufactured by: Primare AB

URL: primare.net

Distributed in the UK by: Karma AV

URL: karma-av.co.uk

Tel: +44(0)1423 358 846



Adblocker Detected

"Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit..."

"There is no one who loves pain itself, who seeks after it and wants to have it, simply because it is pain..."