FiiO S15 Review: Is It As Good As Advertised On Paper?

Unpacking FiiO S15’s features and sound performance to see if this high-res desktop streamer truly delivers on its promise.

FiiO’s Expansive Audio Universe: The Surprising Newcomer

If you’ve ever dabbled in the world of portable music players or budget DACs, the name FiiO portable music players probably rings a bell. This company is known for producing user-friendly, versatile audio gadgets that punch above their price point. But when I took a deep dive into their lineup, I was amazed by the sheer breadth of their offerings—from headphones of all flavors to active speakers, desktop audio gear, cables, and even a portable cassette deck. Yes, cassette! And if you crave vinyl nostalgia, FiiO has a turntable for you, too.

So when FiiO launched its first full-size music streamer—the FiiO S15 audio streamer—I was genuinely curious. They tout it as a “high-resolution desktop audio streamer,” though I have to admit, that phrase left me scratching my head. What exactly does “desktop” mean in this context? The S15 looks like any regular 43-cm wide hi-fi component, and it doesn’t have features that scream “desktop-only.” Heck, it doesn’t even have a headphone out.

Availability and Pricing Outside Official Channels

Currently, the FiiO S15 audio streamer isn’t officially available in many markets, meaning enthusiasts will have to resort to international platforms like AliExpress or European and Asian resellers. This means the price tag can swell once you factor in shipping, customs, and reseller margins—expect something in the ballpark of $1,900 to $2,300 USD for those brave enough to import it.

Using the S15 in Unofficial Markets

A standout feature is its Android-based software, allowing installation of virtually any streaming app, including popular local services. However, the FiiO Control app—which is supposed to make remote management a breeze—can be glitchy and lacks proper localization. No official warranty makes repairs tricky and risky outside authorized centers, so this purchase is definitely for the adventurous audiophile.

Design and Build: A Familiar Yet Mixed Bag

At first glance, the S15 looks like a well-equipped but fairly standard music streamer. It plays music from network servers or USB drives hooked up via front and rear USB-A ports. It supports both wired Ethernet and Wi-Fi connections.

Running on Android 12, you can download apps directly from Google Play. While Tidal and Qobuz didn’t come preloaded on my unit, installing them took only minutes.

Android gives FiiO a leg up in versatility compared to many competitors, yet this also introduces some quirks in user experience that we’ll discuss shortly.

Connectivity: A Plethora of Digital Options

The S15 is packed with digital inputs and outputs:

• Front: USB-C (PC connection), USB-A (external drives)
• Rear: USB-A, optical and coaxial inputs, mirrored outputs, HDMI, HDMI ARC, and a rare HDMI port delivering digital I2S for compatible DACs

Other features include:

• Balanced digital AES/EBU inputs and outputs
• Bluetooth two-way compatible with aptX HD and LDAC
• Analog outputs: two pairs of stereo RCA and one balanced stereo XLR

Storage-wise, it supports SD cards (up to 2 TB) and M.2 NVMe SSDs (also up to 2 TB), letting the S15 double as a media server.

In short, from a functionality standpoint, this device checks almost every box—except the odd exclusion of a headphone output.

Under the Hood: Audio Power and Circuitry

The heart of the S15’s digital processing is a flagship dual-chip combo from AKM: the AK4191 handles processing while the AK4499EX manages D/A conversion. Two high-precision Accusilicon femtosecond clocks minimize jitter for cleaner signal timing.

The analog stage is fully balanced to reduce noise and crosstalk. Power comes from a custom low-noise 35 VA toroidal transformer alongside four hefty ELNA capacitors, ensuring stable, clean power delivery. Separate power lines for digital and analog sections help prevent unwanted interference, which is crucial for maintaining sound purity.

Build Quality and User Experience: Some Hits, Several Misses

The build quality lives up to expectations for a premium device, but there are moments where corners seem cut. The aluminum chassis feels solid and durable, and the crisp, bright 7.84-inch color touchscreen is a highlight. However, the dual rotary knobs feel cheap—too little resistance and a noticeable wobble detract from the otherwise polished feel.

Software-wise, Android’s flexibility is both blessing and curse. Delays in response and occasional touchscreen unresponsiveness hurt the experience. The user interface lacks intuitiveness, leaving you guessing how to find certain settings even after weeks of use.

The biggest frustration is the official FiiO Control app. It’s buggy, crash-prone, and poorly designed. Some instructions appear in Chinese, and notification placement is awkward. Plus, it seems tailored for smartphones, leaving large blank spaces on tablets.

I’m genuinely surprised a company with FiiO’s streaming pedigree released software that feels so unfinished.

Sound Quality: Warm and Smooth, But Limited Dynamics

Now to the heart of the matter—the sound. After hours tweaking filters and settings, I squeezed as much as possible from the S15.

On the plus side, it makes a solid first impression with a smooth, warm, and full-bodied sound. It handles subtle and aggressive tracks with decent clarity and a generally stable output across digital inputs, including Bluetooth, which paired effortlessly with my phone.

Tracks like Norah Jones’ “Come Away With Me” or Sade’s “Diamond Life” sound pleasing, with a balanced tonality and nicely voiced midrange. Vocals come through robustly, and the sound has a comforting boldness. In a market where many devices chase flexibility over warmth and character, the S15’s approach is refreshing.

Where The S15 Falls Short

However, problems arise with more diverse music. Moving from The Police’s punchy Outlandos d’Amour to TLC’s CrazySexyCool, Beethoven’s Seventh Symphony, and Coltrane’s A Love Supreme, the S15 struggles to capture the essence.

The sound feels compressed with limited dynamic range. “Roxanne” loses its raw power, and TLC’s album sounds oddly sterile. The rhythmic drive that should energize is missing, replaced by a safe, uninspiring sound. Low end feels overly dense and lacks definition—bass lovers looking for tight, melodic lows will be disappointed.

Compared to a similarly priced competitor like the Bluesound Node Icon audio streamer, the S15 doesn’t hold a candle. The Node Icon is a darling for its clarity, depth, and resolution, offering transparent sound and rich detail—things the S15 misses.

In my test setups, ranging from high-end Burmester 088/911 MkIII stereo amplifier and ATC SCM50 speakers to more affordable Arcam A5+ amplifier and KEF LS50 Meta speakers systems, Bluesound consistently outperforms FiiO. The Node Icon lets you hear the mix and acoustic nuances in ways the S15 simply cannot match.

Final Verdict on the FiiO S15

On paper, the FiiO S15 audio streamer impresses with its extensive features and versatile Android platform. But considering its premium price, the reality falls short. The core components are there, and the potential is undeniable, but it needs further refinement, especially of its software and sound tuning.

Until then, I’d advise spending your money elsewhere.

Ratings:

• Sound: 2/5
• Build: 3/5
• Features: 5/5

“I’m genuinely surprised a company with FiiO’s streaming pedigree released software that feels so unfinished.”

FAQ

• What makes the FiiO S15 unique compared to other streamers?
  It runs on Android 12, allowing installation of any streaming app, and supports a wide variety of digital inputs, including rare HDMI I2S.
• Does the FiiO S15 include a headphone output?
  No, it lacks a headphone jack, which is unusual for a device marketed as a desktop streamer.
• How does the sound quality compare to competitors?
  While warm and smooth on simpler tracks, it struggles with dynamic range and detail compared to competitors like the Bluesound Node Icon.
• Is the FiiO Control app reliable for managing the streamer?
  Unfortunately, the app is buggy, crashes frequently, and lacks proper localization, making it frustrating to use.
• Can I expand storage on the S15?
  Yes, the streamer supports SD cards and M.2 NVMe SSDs up to 2 TB, allowing it to act as a media server.

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