Synergy
Power
At 4000mW balanced, the K17 is easily one of FiiO’s most powerful, fully balanced desktop amplifiers and integrated players, second only to the K19.
However, the background is very quiet, and unless you are experimenting with sensitive IEMs at the highest gain level, you are unlikely to detect any background hiss.
Pairings
The K17 sounds dynamic and full-bodied with various gears. When switched to lower gain, sensitive headphones such as the Palma DHS-1 punch softly in the bass, sounding quite rounded in the higher registers.
So, there is room to push to a higher gain and make genres like Jazz sound more exciting and defined in positioning. A high gain level would be optimal, but when pushing further, and when more instruments come into the mix, it may start to sound congested and compressed.
With higher impedance IEMs and headphones, such as the Westone Audio MACH 20 and the HD 800s, it sounds full and punchy in the lows without dominating the mids, though darker voices may sound slightly laid-back.
The treble is presented swiftly with a rather sharp roll-off, which is great if you want a relaxing, sibilance-free listen.
With higher gain levels, there is also ample current to drive the bass, with the virtuoso more cleanly separated from the backing. This works well with the 105 AER from Meze Audio, which boosts its brilliance while sounding sweetly rounded.
On a lower gain setting, cymbals and hi-hats are softer sounding and on the shy side. On higher gain levels, I hear a more engaging V-shaped impression from the 105 AER.
I also tested with the more demanding MOONDROP COSMO, which delivered a darker, bassier performance with the top end rolling off sharply.
The parametric EQ would be a great tool in this case to fix the issue and make the overall output more balanced. The onboard equalizer presets are also useful in giving it a quick tweak to sound more open. The dynamic range and vocal clarity can be easily improved without audible distortion.
Select Comparisons
FiiO K9 Pro ESS
Technical
Being the successor to the K9 Pro ESS with AK4191EQ + AK4499EX or the K9 Pro AKM that runs on dual ES9068AS, the K17 packs many more interesting features and components
This includes discrete amping circuitry, doubling the output channels with the 4191EQ and dual 4499EX DAC combo, as well as PMEQ and local playback features.
Using two 4499EX chips on the headphone output, the K17 achieves a marginally higher SNR of 124dB (A-weighted). The discrete amplification also doubles the output from 2100mW to 4000mW at a 32Ω load.
However, the noise floor increases from <3uV to <7.9uV, and the output impedance rises slightly from 1Ω to 1.5Ω. In practice, though, these differences are quite unnoticeable.
Design
The design theme on the K9 Pro series and K17 is very different, albeit their dimension are quite similar, with the K17 being slightly longer.
Both designs are cool, but the K17 is next level with more intuitive controls and a more informative touchscreen display. Perhaps it would be even cooler to combine the design language on both models to create a futuristic look while balancing their respective functionalities.
Another observation is that the K17 is also designed to be placed horizontally, while the K9 Pro can stand upright, which I think is a nice option for smaller desk spaces.
Performance
I compared the K17 with the ESS version of the K9 Pro, and aside from the higher output power, their difference in performance is quite obvious.
While I believe the K17 references the K9 Pro ESS in tuning to keep the output balance in tone, the K17 has a tad bit more brilliance in the treble and enhanced resolution. Combined, this makes it more revealing and holographic in imaging, especially when playing high-resolution Classical music.
On the K17, the mids carry stronger density and resolution and have a more elaborated decay. Transients are more clearly presented on both ends.
Whereas the K9 Pro ESS doesn’t sound as textured and weighted on the lows, sounding softer, not as impactful, and a little rawer, especially in the treble end.
Overall, the K17 feels like a comprehensively improved version over the K9 Pro ESS with a subtler, more M-shaped tuning that strengthens the dynamics and detail retrieval. The vocal is shaped more stereophonic and rounded, and the resolution is stepped up, especially in the lower register.
FiiO K19
Technical
The K19 is the flagship of the series, packing in dual ES9039SPRO decoders for 8-channel output, with an 8-channel THX AAA 788+ amping module, contributing to a mighty 8000mW per channel.
It has an output impedance of lower than 0.6 ohm. Its THD measures as low as <0.0002% and has >128dB SNR and >120dB crosstalk achieved.
The technicalities on the K19 outperform the K17 by a small margin, and the decoding and amping modules are also quite different in design, which is the reason why the two don’t sound much alike.
On another note, the K17 supports streaming features that are not available on the K19, not only limited to local playback but also analogue amping. So, in practice, this is much more “all-in-one” with more possibilities to hook up to different devices.
Design
The K19 has a lovely honeycomb-style die-cast panel and feels much sleeker and more premium than K17’s housing, which is built from folded sheet metal.
I do like the minimalistic approach and industrial build on the K19 a lot but when putting it with the K17, which is geekier-looking with its bigger screen and multiple knobs, it is obvious the K17 beats it in terms of functionality.
The screen on the K17 displays all the current settings information you would need to know. On the K19, you will need to check it on the phone or access the menu.
When you are testing many different gears and need different gain levels, as well as instant switching between outputs and input, you may struggle to do the settings quickly on the K19, which feels more suitable to be dedicated to a fixed setup.
Despite all these quirks, the K19 is beautifully engineered and looks much cleaner in the living room, or vertically placed, doubling as a headphone stand. The K17 has to be placed horizontally and may take up more desk space.
Performance
When testing them side by side as USB decoders, the K17 clearly displays stronger coloration, shaping vocals thicker, sounding more robust with less sibilance.
Playing classical music, the K19 kicks cleaner and firmer, capturing transients with better weight, and is more balanced and extended, giving a better depth of view in the perceived stage.
The K17, on the other hand, sounds richer in the mid-lows and draws the listener closer to the ensemble, putting the focus more on the chamber resonances than the exciting but controlled higher notes on the K19.
The overall technicalities, powerful, agile, and controlled bass response makes the K19 superior, though after equalization, the K17 can come quite close.
The fuller tone on the K17 is more forgiving and rounded than on the more cleanly tuned K19, especially for Pop, R&B, and various genres with stronger bass lines.
Although it doesn’t sound as extended, the bass is punchier and richer, adapting well to different gears and music genres to sound dynamic and lush. Whereas the K19 may get slightly clinical sometimes and may not sound as immersive.
Testing on the highest gain level, the K19 displays a better sense of control with superior vocal separation. It holds together a sharper, more concise vocal image. The K17 also does a good job of delivering energized, fast-recovering bass and controlled treble but may get a little bit hot on the upper end.
If you are listening mostly to streaming content and would like to swap between different IEMs and headphones that are not too power demanding, then the K17 would be a lot more fun and practical with its engaging warmth in the tuning.
My Verdict
Before receiving the K17, I was skeptical about its potential overlap with the K19, especially given their similar price points.
FiiO certainly makes it challenging to categorize their products, but in practice, the K17 feels distinctly different, not only the retro look but the tuning and features being offered.
Overall, the decoding resolution is decent, and the discrete amping circuitry provides a pleasing sense of “analog warmth”, which sounds pretty enjoyable with many genres of music I streamed. However, I wish it could sound slightly more revealing in the treble so I could save having to EQ it.
Coupled with PMEQ, multiple gain levels, and other features such as local playback, the K17 is a satisfying and versatile desktop DAC and headphone amplifier experience.
I find it probably the most fun and positive offering from FiiO to date, and a cool upgrade from the K9 Pro.
FiiO K17 Technical Specifications
- DAC: AK4191EX + AK4499EQ * 2
- USB Decoding: XU316
- Bluetooth Decoding: QCC5125
- AMP: MJE243G/253G Discrete Transistor Current Amplification Headphone Amplifier
- Weight: Approximately 2750g
- Dimensions: Approximately 244.6 x 213 x 66.8 mm
- Bluetooth Receiving (5.1): SBC / AAC / aptX / aptX LL / aptX HD / aptX Adaptive / LDAC
- Display: 3.93-inch LCD (240 x 1020) Bezel-less Screen
- PEQ: Supports Global 31-band PEQ (No PEQ Processing in Digital Output)
- FiiO Control: Supports Settings through the App
- WiFi: Supports 2.4G / 5G Dual-band WiFi
Max Supported Sampling Rate:
- USB Decoding: Up to 768kHz/32bit; DSD512 (Native)
- Coaxial Input Decoding: Up to 192kHz/24bit; DSD64
- Optical Input Decoding: Up to 96kHz/24bit
- Coaxial Output: Up to 192kHz/24bit; DSD64
- Optical Output: Up to 192kHz/24bit
- Streaming Decoding: Up to 384kHz/32bit; DSD256 (DOP)
- Local Playback: Up to 384kHz/32bit; DSD256
