FiiO K17

FiiO’s Retro revolution continues with the outstanding and updated K17

FiiO has been at the forefront of the modern “retro” audio movement, releasing nostalgia-inspired products such as the CP13 cassette player and TT13 turntable. With the K17, FiiO integrates this classic aesthetic with the latest in high-end DAC and amplifier technology, creating a product that is both visually appealing and sonically exceptional. The K17 is not only an evolution of the highly regarded K9 Pro, but also a step into new territory, offering an unparalleled blend of retro cool, power, audio precision, and features.

Beyond its stunning retro-inspired design, the K17 is an exceptional feature packed DAC/Amp that can drive even the most demanding headphones with ease. I have been using it with some fairly challenging headphones in recent weeks using it heavily when evaluating the Modhouse Tungsten, some demanding Sennheisers and also with the Hifiman HE6S2 V2 all of which scaled implacably well with the 4W of power from the K17.

I really appreciate how the K17 feels like the culmination of several design and feature trends we’ve seen in FiiO products in recent years. It brings together high-quality internal components, a wealth of advanced features including robust PEQ support and a screen that greatly enhances navigation and configuration. It also confidently embraces a retro-inspired aesthetic that sets it apart.

Updated Review

When I originally wrote this review, I felt the K17 still had a few too many bugs and was still missing some key features, but I have noticed many firmware updates in the last few weeks, especially the latest firmware that it received over the weekend:

These updates combined with some updates to the FiiO control mobile app has finally sorted out most of the issues that was holding the K17 back, and therefore I felt I should update this review for more clarity. I highlight some of the section with a “Update:” prefix below to show which sections where updated.

But let’s start with the unboxing experience.

Unboxing and First Impressions

The FiiO K17 arrives in the typical impressive premium package that immediately sets the tone for a high-end experience:

Back of the box:

Opening it up you get a warning about the power supply:

There is actually a switch for 120V or 220V on the underneath so it is important that this is correctly set for your voltage requirements.

Removing the warning you see the K17 wrapped in a protective cover:

Taking everything out of the box, you’ll find:

• The K17 unit
• Power adapter and cable ( I got 2 with a UK and a EU plug )
• USB cables (Type-C and Type-A)
• Optical and coaxial cables
• Infrared remote control
• 6.35mm to 3.5mm headphone adapter
• XLR protective cap
• User manual and warranty card

The remote is a nice feature for those you want to set up the K17 in a Rack or even just outside of arms reach, I like some of the button choices on the remote including the ability to switch EQ profiles:

There is plenty of cooling grills on the K17 though it never felt hot to me:

Build quality

The build quality is exceptional. With an aluminum alloy chassis, tactile physical switches, and a gorgeous color LCD screen, the K17 exudes both a premium, vintage HiFi feel, yet it feels modern.

The back is equally impressive with plenty of connections:

A VU meter animation adds a touch of nostalgia:

Both the black version (which I have been using) and the silver version are showstoppers, evoking memories of classic 1970s and 1980s stereo components with the various dials, yet it still has the modern touches you need in 2025, like the touchscreen and displaying Album Art and metadata when streaming or local playback.

The dials are well-thought-out with the volume and a quick menu selector on the right hand side:

Here is a brief animation of the menu navigation using the menu dial:

And dials for on/off, output selector and gains levels on the left hand side:

The device is relatively compact for its capabilities, featuring an intuitive 3.93-inch LCD touchscreen that makes navigation effortless. I really like the usb-c connection on the front, this makes it easy to connect a laptop or a mobile when setup in your hifi rack or possible when using the K17 as a DAC in a desktop setup like this one:

Though to be honest I think it is a little big for a working from home desktop setup (at least in my little setup), especially if you want desktop speakers on the same desk, so I mainly used it in my main hifi setup.

For comparison, the JDS Element IV is much practical device for a smaller desktop:

And of course the FiiO K11 / K11 R2R are also decent desktop headphone dac amplifiers for these smaller setups:

Wired Inputs

As you can see in the photos above there are a lot of wired connections:

• USB x 3 (2 on the back, one larger USB ideal for an external USB device)
• A RS232 “usb” interface (for firmware updates)
• A 12V Trigger input
• Optical
• Coaxial
• RCA Line-In
• Ethernet (it also has Wifi and Bluetooth)
• A 4.4mm balanced input ( an unusual option, but I guess they didn’t have room for a XLR balanced input)

Wired Outputs

• RCA Line-Out
• XLR Balanced Out
• Coaxial
• Optical Digital Outputs

Features

The K17 is so packed with features that I couldn’t include all of them, so I picked a few key things I think everyone should know about the K17.

First some details about the internals which you can peak at through the grills:

FiiO provides lots of technical information on their website here, but I liked this diagram showing the physically separate boards used in the design:

Flagship AKM DAC Implementation

• AK4191 + Dual AK4499EX DAC Chips for reference-level sound quality
• Advanced power supply design with physically separated circuit boards for reduced noise
• Fully balanced design for minimal crosstalk and enhanced clarity

High-Powered Amplification

• 4000mW per channel (balanced output)
• Discrete Class AB transistor current amplifier for powerful, clean output
• Can drive everything from sensitive IEMs to high-impedance headphones with ease

Firmware updates

My unit received a software update within a few days of being setup. This update was split into 2 parts one worked via the local usb disk method to update it:

But the second part of the update required using a computer and mine got stuck when using my Macbook to apply the MCU update but when I switched to my Windows Laptop the update was quickly applied:

This initial update was pretty extensive:

Update I am currently on v193 and most of the issues I had with the K17 are now solved and the update process is now OTA so a much simpler process.

Streaming Support

FiiO talk about 8 different modes of playback and as well as RCA Input, Balanced Input, Optical and Coaxial there are a few “Streaming” modes.

Roon

Update - I also noticed the K17 has now received it own Roon certification.

One of the standout features of the K17—particularly if you’re a Roon subscriber—is its native Roon support, which makes it feel like a truly complete device. Simply link your Tidal account within Roon, and you’re presented with a visually elegant and highly functional streaming solution housed in a beautifully designed unit. From there, all you need are your headphones (and perhaps a pair of powered speakers) to enjoy a fully integrated, high-end audio setup:

Bluetooth and Airplay

These options work as you might expect - though you need to be using the right input for the K17 to be seen when “cast” via bluetooth or Airplay.

With bluetooth you clearly see the codec being used:

APTX-HD	LDAC

I tested with my iPhone, and it supports the AAC codec as well.

But when using an Apple device you can use Airplay 2, but as ever with Airplay 2 you can see the iPhone has converted the bitrate down to 16Bit/44Khz:

USB DAC

But for those who want lossless audio the USB DAC works great presenting lots of high def audio output options:

Local playback and the FiiO Music Application

Another option for lossless playback is using your own local files. Simply load up a USB drive with lots of own FLAC / MP3 files, and you can update the built-in local music with metadata including album art and use the remote or navigate the music using the onscreen browser:

You can actually use the FiiO Link support with the FiiO Android and IOS apps to remotely control and navigate your local music library while not quite as convenient as an App like Roon or WiiM’s mobile app for their Streamers, it is a perfectly good solution for remote controlling playback of music from your Smartphone.

Note: On my iPhone, I had to enter the IP Address of the K17:

But once I did I could remotely control the playback - though the album art was not shown in the App but was on the K17 screen:

FiiO also fixed an issue where the registered IP address of the K17 might end up changing. So now it is much more consistently allowing me to control the K17 using the FiiO Control mobile app on both IOS and Android:

You can even remotely browse the attached local files and trigger playback:

And you can still control the music remotely which is nice:

Overall the remote control experience has been greatly enhanced with the latest K17 firmware updates and I hope to see some more updates in the coming months, but for me the K17 is now a much more complete device than it was a few weeks ago.

Update: Analog and Digital inputs

I forgot to mention in my original review the quality of the digital inputs, but I have been using my DM13 cd player both as a “cd transport” into the coaxial input of the K17 and as a test into the balanced input. It sounds excellent using either path:

Screen and UI Navigation

The on-screen menu system is very intuitive with a Home and a Back on each screen:

Update 31-Band Parametric EQ (PEQ)

You can switch on EQ and switch between the different presets both physically on the device as well as using the remote as seen in this little video:

And you can finally edit the EQ using the FiiO Control application both on IOS and Android:

But we are still missing the ability to use the FiiO “Control” Website https://fiiocontrol.fiio.com to edit those filters but hopefully this feature will be added to the FiiO Control website soon and its lack doesn’t really hold the K17 back in any meaningful way.

I can now finally assign one EQ profile specifically for my external speakers via the Line Out, while reserving other customizable PEQ profiles for various headphones and IEMs in my collection. This level of flexibility significantly enhances the K17’s appeal for users with diverse listening setups.

Sound Impressions

The FiiO K17 delivers an incredible powerful transparent sound signature. Unless you want a “warm” Tube sound from your Amplifier, this is the sound you should strive for. A true end-game level of power and quality.

Bass

The bass is tight, textured, and authoritative, never overpowering but deep and controlled. The K17 delivers * clean sub-bass extension* without bloat, making it an excellent choice for bass-heavy genres and orchestral music alike.

Mids

The midrange is lush and natural, with superb vocal clarity. Whether it’s jazz, acoustic, or rock, vocals sound intimate yet spacious. Instruments have a lifelike presence, making the listening experience truly immersive.

Treble

Treble is smooth yet well-extended, free of harshness or excessive brightness. Cymbals have natural decay, and details are presented effortlessly without fatigue.

Specifications and Measurements

Audio parameters:

6.35mm Single-Ended Headphone Output

4.4mm/XLR4 Balanced Headphone Output

Line Output

FiiO Measurements

Note: These are some measurements that FiiO provided - I have them copied here for completeness:

32 Ohm Single Ended output to the headphone jack on ultra-high gain - gets a very respectable SINAD value of 105/106:

32 Ohm Balanced Output to the headphone jack on ultra-high gain also get a very similar SINAD score:

And finally Balanced LO and RCA where similar (this is the Balanced):

Note: This isn’t SOTA but is respectable and above any level where you might hear noise.

The frequency response curves were flat to > 40K, so I didn’t bother to include them - but you can check them out here

Distortion

Distortion is excellent

Update: Rating

I have now given the FiiO K17 a 5-star Pragmatic Rating. From a hardware perspective, it was always an outstanding end game device offering a striking retro design, robust build quality, and ample power for virtually any use case. And finally with the latest updates, it feels like a finished product.

The K17 now performs exceptionally well across multiple use cases whether as a standalone DAC, a high-power headphone amplifier, or a Roon-ready streaming endpoint. It really is a Jack of all trades and a master of most of them device. With the latest fixes I feel now the K17 is a category-leading audiophile product in the sub $1000 range.

Conclusion

The FiiO K17 feels like an end game device, one that FiiO have been leading up to for a few years with the 3 pronged approach to audio products, embracing retro designs, incorporating high quality audio components, providing massive amounts of power and adding key audio features like PEQ filters, that are now finally easily editable.

Operating the K17 is a joyful, tactile experience, thanks to its physical switches and intuitive touchscreen interface. The VU meter animation, though slightly laggy, adds to the vintage charm. If you’re looking for a high-end DAC/Amp with no compromises, especially if you are a Roon user the K17 is an easy recommendation.