This is the best streamer of 2025, but it is just not for me... yet FiiO S15 review

*My unit have been damaged in the transport, but it was just cosmetically and nothing on handwear level. As of long waiting time to receive device, and even longer to return it and to receive a new one. And my listening and analyzing takes a long time. I decided to use this device, and do this review. For more details and product photos and videos look at video review.

Fiio just can`t and won’t stop to create amazing gear. They had a pretty good swing with K15 and K17, especially K17 being such a versatile and great product from DAC, streaming and headphone amplifier perspective. They had M21 and M23 DAPs, which hold a lot of value in their price range. They have R7 and R9 products that I really love, especially their quality of DAC, headphone amplification and I love that form factor.

Fiio covering an entire market with class and value leading products

But now they want to try their luck in full-fledged desktop audio streamer in competitive price range, which is only purpose to be your DAC streamer. In a very crowded price range of 1100 euros. And on paper this device truly rocks, as what I have seen it has an incredible spec sheet, and it just won the EISA award for the best streamer, which is a prestigious award, especially for FIIO to defeat all other more established players. But will I like all that more than some already established favorites let’s find out.

As you might have noticed by now, Fiio already have two lineups of streamers their R series and K series. The both lineups want to act as versatile devices aiming at headphone enthusiasts, but one being more of a purist device than other. But S series of Fiio tries to grab that thunder that devices like Eversolo put to try to give maximum output from DAC and streaming. It is less versatile but more of a savant of device. So headphone peeps sorry but you need separate headphone amplifier. But for the rest, let me assure you what Fiio does here is maximizing its potential in this value here.

This is why this device is just so magnificent and unique

It is crafted from components which you expect now in this price range, they did not skip on anything. But let’s not get out of ourselves. Let’s talk first about looks and then features.

Device looks good, nothing that blew me away, but it has certain Fiio design language. So if you like that you are going to like this device as well. It is not a small device, it is a big one, but the quality and sturdiness of materials is amazing. At front two buttons and one big screen.

That screen is certainly a highlight, as it is big, with vivid colors and responsiveness. It works on an Android platform, so the UI is almost like outdated Android operating device. If you like that then you know what you are up to, but for me.... wait a little longer to hear my thoughts about that.

But I love big bold screens and this is the one.

Back of the device is just mind blowing, honestly it is. Fiio’s philosophy was “what you want we have.” I was surprised how far did Fiio think, and is probably indicator for who this device is. But they will give you a shell, a HD cage for SSD hard drive, so you can slot it inside the device, it has a dedicated space inside device for it, so it can seamlessly work together and not have hard drive dangle and hang outside of device. I have no words for smart thinking like this. It fits beautifully and you even get small USB-C cable to connect it without making the device larger and cables dangling everywhere. Love love love this one.

But you also get believe it or not SD card reader, I honestly don’t know for who this is, but wow.

You get HDMI and HDMI ARC, which again I sure love, having art and lyrics at your TV is just super convenient. It also has I2S, it has 2 USB-A and 2 USB-C (one each at back and front). Really smart thinking from Fiio for those who use USB sticks to play music, when device is close to the wall. You have AES/EBU IN and OUT (that is rare).

You have 2 coaxial and 2 optical in and out. You have line in RCA, and not just one but two sets, so you can connect two sets, in two zones, two speakers.... You also have XLR outputs, and you have grounding and trigger out.

And yes I forgot Wi-Fi and Bluetooth antenna, and Bluetooth antenna with APTX adaptive and LDAC.

So this amount of flexibility and connections is amazing, and it should be in this price level. Fiio with this shames everyone.

But also inside is equally impressive. You see, Fiio opted for big device, but there is a reason for that. They have chosen to separate all the components, with electrical shielding, to have clean output on every component. This is something you see in quality build expensive devices, how it separated inner components in three partitions. You get 35W linear power supply, absolutely yes!

DAC is AKM 4499EX which is current flagship of AKM, I spoke many times on this channel around it, but it is great and detailed. Also I have to give props to Fiio for a very detailed explanation and schematics of inner components. They have nothing to hide when it is this quality. These DAC can rival easily DACs to somewhere 400 euros in price. This is the same DAC configuration that you can find at much more expensive Eversolo DMP A8.

They used very quality Audio capacitors, isolators and Clocks. If you want to know more go to the Fiio website.

So versatility of this device is huge, as a streamer, as a preamp, as a digital hub for all your needs. As a DAC, as a connection to music servers etc. There are a couple of ways to connect to this device wirelessly. You can use DLNA, you can use ROON ready devices, Airplay, Bluetooth and Android mirroring via Fiio connect application. One thing to notice is that support for Tidal is extremely poor, and if you use Tidal it is a subpar experience. It is much better with Spotify, Deezer, Qobuz etc., but Spotify Connect or Tidal Connect is non existent as there is no Chromecast on this device. So keep that in mind for future.

There is also great and extending reaching equalizer, with both parametric and standard equaliser, and also effects like width, bass, treble, balance etc. It is just adding more and more on flexibility scale.

With all of this you get remote, and it is just truly fully what something that costs 1100 EUR should be. All on max, and quality components and everything for amazing results. I cannot give it enough praise here.

Sound Quality - the good and amazing

So how does it sound after so much praise I have given for flexibility and build quality and inputs/outputs. Well really good.

Honestly the sound was how I expected it, as after reviewing for a long time. When you have in front of set of elements, you kind of already know in what way they will behave and sound. And if I can commend one specific trait which is super underrated in this streamer is how it allows music to be dynamically rich.

Yes dynamics here are outstanding. It is a shining bright star of this streamer, Bass had this commanding reach and presence. But also a lot of expression in treble and highs.

Some might enjoy this superbly, as it makes the music fun, more driven more energized. That characteristic will be your driving point with the sound. It also needs to find that spark in you that just love some good rock music, or some jazz. This will help your speakers if they have tendency to swing.

As when I had Menuets on them, the bass on Menuets is ok, nothing to write stories about. But it did manage to push that little bit more from them to sound more commanding and more present. When I put Wharfedale Linton, which is a different tale all together. You can see speakers which are bass talented become just massive. And in the way that quality source like this one manages, not to become bounce or bloated to the point that delicate texture of bass get lost.

Bass is a place where texture and details can get easily lost, especially when the room acoustics are not decent, for a sake of massive boom and bop. But you should never accept that, expect that you can hear cello, double bass, deep growls of voice. They all have timber, even though it is not easy to be heard. And this is a quality source which allows your speakers talent if they have to flourish and become more precise without cutting the bass too much.

Yes, streamer, same like any other source is a helper not a star of the show. It will not fundamentally change the sound of your system, but it will help in enhancing its talents if they are there. If your speakers don’t have something do not expect for it to magically appear now.

Same thing can be said for the dynamics and treble. And this is a signature synergy of AKM. It is detailed, forward and sometimes merciless. But it helps some speakers flourish here. Say you have KEF LS50 with you, it will make them a bit more agile at top. Because it knows that precision, synth leads, lead guitars need push. And you can truly feel edges of instruments there, they are real and forward.

Details and texture make them more real on soundstage, your organics, materials from which in product boots of your song. Have something like blues guitar here with its real live feeling to it, and you feel that raspiness of textures, that breath in that room, just that kind of production and mastering works here. So detailed textured presentation.

The voices are a bit sharp, and forward, and while you might miss some presentations where it is smooth, and clear and have a lot of space and breath around them. But they will have weight when needed, they will have details, texture and presence when needed. They will jump at you and be full of life.

But for those ballads, chamber music, some pop not all, you might want a bit softer smoother presentation, with a lot of clarity and room to breathe. But you get something and you lose something.

Sound Quality - not so good

And while we are on subject of that, let’s speak about two things which are not bad, but could be better. Transparency is one of it. I love how some streamers allow some of my speakers to be more decluttered, more insight in that blackness of background.

I like sometimes to lower the tension, and just relax or be clinical. In those moments I value most out of everything some room to analyze, some coactualization on soundstage that allows me to listen hear it and say AHAAA. It is not that this streamer does not allow that. But you know it could give more space between instruments.

It could allow me not constant barrage of details and textures, but some breath, timber and decay to last longer. For me or to relax in way to not analyze it whether I want or don’t want. Again this is not a minus just a preference.

The second thing is soundstage. Again it is good, but nothing groundbreaking. My Focals, and Q Acoustics can attest to that. I wished that like some other streamers it would push soundstage more horizontally. It packs stuff a bit too dense, not much airiness, even with airy speakers. So the soundstage does not bloom so much. I just wished more of a precision and width to instruments where on this grand stage they belong. Not that Fiio does not bloom, but a bit more push in vertical and horizontal could make this a killer deal all together.

So the sonic quality of this streamer is great. It is maybe even best, it truly is absolute masterclass in dynamics. Texture, details, presentation is also top notch. If you value energy, presentation, details then this one is absolutely for you you will not be disappointed there.

Synergy and pairing suggestions

While talking about pairing and synergy it is important to know that this will not have such a powerful influence on your sound as amp or speaker, rather it will enhance some areas of your already HIFI system in house. But still it great to know what kind of gear will mostly benefit from it.

Honestly with its dynamic richness, most will benefit are balanced and neutral speakers. As they will have boost in decibels in both bass and treble. So something like Elacs, Dynaudio, KEF, Acoustic Energy etc.

But it can also go good with some speakers that don’t have good bass response like some Dalis and Bowers and Wilkins, as it will give it more gravitas. Maybe the combination that least benefit from this are some darker bassier speakers. Not that it will sound best, but this streamer enhance some areas that these speakers already excel.

But this device is just not for me

But unfortunately I have to speak why this amazing device is just not for me. And I wanted to love this device so so much. As when I heard at SIAS 2025 I fell in love with it. But... The user experience of it is rather bad.

No, let say it like this, this device want to be everything to everyone, and it is, it covers so much ground. But I wanted it to be amazing streamer for me. And while sonically it is, convenience wise, and just ease of use it is not. I actually had so much problem with it, that All other streamers I will compare it here, plus few others I did not, I always gravitate to them when I was done side by side them. For simple reason is that For my Bluesound Node Icon for example, I Just pick up my phone, play a song on Tidal and it just works. Art appears on Icon, music plays, I easily navigate to other album etc.

With Fiio it is always extra click, extra step, extra manoeuvre to do. I mean even if you use Spotify android mirroring, to show playback at your screen of S15, you have to navigate to Fiio Playing. But that is just an app, so unless you turn off the screensaver after some time it will jump to UI of screensaver. And if you jump somewhere else, that is not Fiio Playing to pause the song, you have to return to that application to pause it.

But because it is an external 3rd party application you cannot search in it or see the list of songs. Just to play pause and next and previous track.

Some cool stuff is that if you use Spotify, you will at some tracks have videos playing on the screen I love that, but Spotify and Qobuz are not meant to be used in that weird aspect ratio. They are not natively built for this streamer, so to use these applications while something becomes better other things become so harder to navigate and use.

Still the best way is to use it on your phone, but the connection is not coexistent if you play music over your phone, you have to navigate to Spotify app, or Fiio playing app. And good luck to activate currently playing on Spotify app on S15, for that the best thing is Fiio Playing app. But I already explained problems with Fiio Playing app.

Without classical connect methods, connection with streaming services is fiddly, and often breaks. The FiiO connect application, is kinda half baked, and is laggy and also often breaks. But even when it works at mobile phone it uses the same aspect ratio as your screen and it looks very bad on your phone or tablet.

So experience was so poor and subpar that I was shocked, honestly, it feels that they had Android, and did not have enough man power to adapt it to modern standards of streaming.

But I was thinking ok, this is poor, but maybe the experience of playing my DSDs from my SSD will be better. It didn’t haha. I calculated that when I turn on the device I need 4-5 clicks and some waiting time to access my files and play the songs. And whole experience felt like 2012 or something. Why? Just why I don’t get it, this all could be done so much better.

If the app was not super laggy, and constantly losing connection, it might remediate the pain a little bit... but it is just not.

And I guess if you are a person that uses this device with your data server like NAS, or with direct connection with your PC, so you do not have connection with this via mobile you might not experience problems that I did. But I use this as a regular streamer, as I seat at coach and I want to enjoy music. But IF you can somehow find a turnaround around all this want I spoke now, then you are lucky as this streamer as phenomenal.

I felt that some functionalities in app, or on remote control could help greatly.

I had so much frustrations with software, that I cannot see myself to use this as my daily driver. And I was so sad, so sad, as I wanted this to become my favourite new device. As it looks great, it has an amazing screen, it has so much inputs and outputs, it has horsepower and innards to race forever. It should be the best, and for some maybe it is.

Competition

I had two competitors of this device with me so to side by side them. And these two competitors lie in the same price range so it is perfect. That is Bluesound Node Icon which is equally priced, and Eversolo DMP A6 which is a bit cheaper, but you have Master edition which is bit more expensive from it.

vs Eversolo DMP A6 and A6 Master edition.

The closest comparison is Eversolo DMP A6, and especially DMP A6 master edition. The way I say it both sonically and the issues I have with S15 exist in DMP streamers.

They sound similarly, they are both detailed, textured and dynamically great streamers. S15 might just bring more in bass and more in treble so as a streamer maybe sonically you can prefer more the sound of S15.

The S15 just added more extension to bass, it just sounded more commanding, and treble had more rounded sound with certain tracks. More details and texture to truly make it more alive. But the sound is close to each other, this is not what I am saying a earth and the sky, so you can easily detect different sound. They were very similar but I think S15 had just a bit more mature sound.

S15 have lot more connections, inputs and outputs and flexibility in what it can do. But I personally prefer more Eversolo’s software, even though it is far from being perfect as well. As I think UI and UX of their software is much better, it just works much better as well. I also prefer Eversolo’s screen more, and just size and weight of unit.

Which I would choose. If I had both standing next to each and I wanted best sonics I would probably go S15, but for my daily driver I would choose A6 master as I just enjoy so much more using it.

One add one Eversolo T8 is out, and it is in similar price range. I have not heard it, and that might change few things for me. But for now I speak only from things I know.

Bluesound node icon

vs Bluesound Node Icon

So how about my favourite streamer in this price range. How about Bluesound Node Icon. The interesting thing is how differently they sound.

Everything that I said S15 could do better, Node Icon does. It is more clear and transparent, it has better soundstage. It just weaves music more subtly and musically authentic that I really enjoy.

But as I said in my review S15 is a dynamically richer device. There is more detail in top end. And certainly better how it works and channels bass. And then you find yourself at crossroads.

Sometimes I love Node Icon more than S15, but sometimes when I play Dire Straits, Led Zeppelin, A Perfect Circle I just enjoy so much more S15. With how much energy and gravitas it brings. But with rock music it is important as it also channels a lot of passion and emotions that way.

It is more driving sound that helps your speakers that have that great driving energy behind them. But sometimes I listen to Steely Dan, I listen to some Joni Mitchell, some Dead Can Dance and that soundstage is everything and how clinically I can assess instruments on soundstage. Where they are and their scope, timbre and presence.

Sonically it can go both ways to be honest and it is more what kind of audiophile you are will be is these device for you or not.

But there is a big but. S15 is dramatically more richer in inputs, outputs, features and just much better flexibility in what it can be. S15 has better screen. S15 has a better DAC. S15 can be more things for more people for its applications and software and how much it allows versatility how you connect it. Including that added SSD slot, so much more USB-C and A inputs. DLNA etc. It is just so much more feature and outputs and inputs packed.

Bluesound Node Icon does have two aces upon its sleeve.

First it is most easiest to use. It is simple, but I like it as I only use it as streamer. It is easiest to connect, and react and interact with it. I click on the song and voila it is appearing on Bluesound Node Icon screen. I just prefer this much more to all other streamers. Just less objects between me and music. Even though feature wise it is simple and not as flexible as S15.

One thing more, it has really decent headphone amplification inside. It is incredible actually how good it is, how little Bluesound Node actually promote it. It is THX AAA certified, and it can drive plenty of headphones, and with DAC inside truly be all in one solution.

So I would still prefer my Bluesound Node Icon for its ease of use. But I would certainly miss that energy, that details and just overall presentation of S15. If only I loved S15 software I would be singing different tune now. But until when I start to enjoy S15 software I am still a bit oriented to Bluesound Node Icon. But when it does...

Conclusion

By now you know what I feel, this is the device in my opinion that have a tough time understand what it needs to be, a crisis of identity. It is all for everyone, and yet in that way it become a shattered dream for me.

Is this device great, yes! It is maybe a best streamer on market if you look at it from perspective of sonics, versatility and build quality. It is dynamically really rich, detailed sound. It helps your speakers with bass so much that it is a big strong point. It has clear output which is really dynamic, and just it is a great companion to your other HIFI Devices.

But it is just not for me, I want to have device that remove as much as obstacles between me and my music. As music is what I came here for. And Fiio just don’t do that for me.

I have crossed my fingers that next device is going to fix many problems, and remain as quality as this one. I want that, I want that next device, for me to say proudly this is the one, buy it, it is nothing like this on market.

But for now for me it is not. But for you, if you think I talk rubbish in my problems section. You use mostly your PC, or music server to streamer music, then buy this device, as it is sonically incredible. And you will be amazed by what it offers in this price range. As none offers more in this price range.

Well until that next time, keep daydreaming and see you on next video.

Pros:

• Outstanding build quality – Premium materials, big vivid screen, and excellent fit and finish give it a flagship feel.

• Massive connectivity & flexibility – HDMI/HDMI ARC, I2S, 2×USB-A, 2×USB-C (front & back), AES/EBU in/out (rare), dual coaxial/optical, dual RCA line-ins, XLR outputs, grounding/trigger out, Wi-Fi/Bluetooth with LDAC & aptX Adaptive, SD card reader, and a dedicated SSD slot with internal cage for seamless storage integration.

• High-end internal design – Separated internal components with electrical shielding, 35W linear power supply, and flagship AKM 4499EX DAC rivaling far more expensive streamers.

• Versatile roles – Functions as streamer, DAC, preamp, and digital hub, supporting DLNA, ROON Ready, AirPlay, Bluetooth, Android mirroring, and a powerful parametric/standard EQ with extra effects (width, bass, treble, balance).

• Dynamic, energetic sound – Exceptional dynamics and bass authority, detailed treble, textured mids, and ability to enhance speakers’ natural strengths (especially neutral/balanced ones).

• EISA Award-winning – Recognized as one of the best streamers in its class, with a spec sheet that competes above its price range.

• Excellent value – Offers more features, inputs/outputs, and sonic performance than many competitors at roughly the same price.

Cons:

• Poor software & user experience – Laggy, unstable Fiio Connect app, frequent connection drops, awkward Android-based UI, and no native Spotify Connect, Tidal Connect, or Chromecast. Navigation requires multiple clicks and extra steps for basic tasks.

• Streaming service limitations – Tidal support is subpar, and third-party apps like Spotify/Qobuz run in odd aspect ratios, making playback control cumbersome.

• Slow file access – Playing local DSD/SSD files demands several clicks and long wait times, giving a dated, 2012-like experience.

• Soundstage limitations – Good but not expansive, lacking airiness and wide horizontal/vertical spread compared to some competitors.

• Transparency could be better – Instruments can feel slightly dense and less separated, with less “black background” clarity than top-tier streamers.

• No built-in headphone amplification – Unlike Bluesound Node Icon, requires an external headphone amp for headphone users.

• Large footprint – Physically big device, which may not suit compact setups.