FiiO K15
FiiO K15 is the K17 younger sibling with the same good looks and similar features at a very Pragmatic price
The FiiO K15 is the latest DAC and Headphone Amp (and more) and is the younger sibling to the highly acclaimed K17. It offers an impressive package that maintains the looks and most of the K17 premium features and performance that made the K17 exceptional, but at a more accessible price point of $549.
What makes the K15 particularly compelling is how FiiO has prioritized keeping the elements that matter most: the striking retro-inspired design, powerful amplification, comprehensive connectivity options, and advanced features like streaming capabilities and parametric EQ. The result is a device that delivers 90% of the K17 experience at a significantly lower price point.
I would like to thank FiiO for providing the K15 for this review.
If you are interested in finding more information about this product, click here via non affliated link.
So having been listening to the K17 for the past few weeks my main thoughts are really, if the FiiO K17 did not exist, this would probably be my top choice for Desktop Headphone DAC amplifier. As FiiO has achieved something clever here – they’ve preserved the core experience of their flagship desktop DAC/Amp while making some strategic compromises that most users will barely notice in everyday use. So fundamentally, the K15 is the better value amplifier, but if you have the money, the K17 does offer you that little bit extra.
But before I get into the details of the differences, let’s have a quick look at the unboxing experience:
Unboxing and First Impressions
The FiiO K15 arrives in very secure packaging:
But removing the box from this packaging, you immediately get high expectations for the device inside:
The back of the box provides some details about the product’s features and specifications:
Opening the box reveals the K15 nestled securely inside with extra padding that protects the device during shipping:
A closer look at the unboxing experience shows the careful attention to detail in the packaging:
The complete package includes:
- The K15 unit
- Power adapter and cable
- 2 USB cables
- Infrared remote control
- 6.35mm to 3.5mm headphone adapter
- XLR protective cap
- User manual and warranty card
The remote control provides convenient access to the K15’s functions, including the ability to switch between EQ profiles. It’s similar to the remote used with other FiiO products, and I like how the device name is printed on the remote itself:
Here’s another view of the remote that comes with the K15 compared to the K17 remote:
Build Quality
Just like the K17 the build quality of the K15 is exceptional, especially considering its price point, I find it amazing that FiiO could do this as it really is the same experience as the K17. With an aluminum alloy chassis, tactile physical switches, and a gorgeous 3.93-inch LCD screen, the K15 exudes a premium, vintage HiFi feel while incorporating modern technology.
When compared to the K17, you can see the similar design language that FiiO has maintained across their product line:
The back panel offers comprehensive connectivity options:
Here’s a comparison of the back panel with the K17, showing similar but slightly different connection layouts:
The main difference on the back is the lack of Optical and Coaxial outputs and the addition of a separate DC power
supply option on the right hand side:
Like its sibling, the K15 features a gorgeous screen with the same UI as the K17, including a VU meter animation that adds a touch of nostalgia to the modern interface:
Available in both black and silver finishes, the K15 maintains the retro-inspired aesthetic that has become a signature
of FiiO’s recent products. The dials are well-designed and intuitive, with volume and menu selection on the right side
and power, output selection, and gain controls on the left.
The underside of the unit features cooling grills that help maintain optimal operating temperatures:
The device’s dimensions (244.6 x 213 x 66.8mm) and weight (2,100g) give it a significant feel without being unwieldy, though while it can be used in a desktop setup, I find both the K15 and the K17 slightly too big for my Work from home office desk. But with larger desks it won’t be a problem and it is perfect for integration into larger audio systems.
Features
The FiiO K15 is packed with features that would be impressive at any price point, let alone at its $549 retail price.
Before I get into some of the specific features, I thought it would be useful to include this small section with the key differences between the K15 and K17 as I don’t go into all the features of the K15 because it shares 90% of its features with the K17. So please read my K17 review on Pragmatic Audio
FiiO K15 vs. FiiO K17
The most obvious comparison is with the K15’s more expensive sibling, the FiiO K17. Here’s how they stack up:
| Feature | FiiO K15 | FiiO K17 |
|---|---|---|
| DAC Chips | Dual AK4497S | Dual AK4499EX + AK4191 |
| Max Power Output (32Ω, Balanced) | 3,000mW per channel | 4,000mW per channel |
| PEQ Bands | 10-band | 31-band |
| Outputs | No Optical / Coaxial Outputs | Both Optical / Coaxial Outputs |
| Power Supply | Both AC and DC options | AC Only |
| Price | $549 | $989 |
Despite these differences, the K15 maintains the core experience of the K17. The sound signature is remarkably similar, with the K17 offering slightly more refinement in micro-detail retrieval and a bit more power for the most demanding headphones.
For most users and with most headphones, the differences will be subtle. The K15 represents an exceptional value proposition, delivering 90% of the K17 experience at a significantly lower price point.
But let’s delve into some of the unique features of the K15:
Dual AKM AK4497S DAC Implementation
At the heart of the K15 are dual AKM AK4497S DAC chips, part of AKM’s new “VELVET SOUND” range. These premium chips deliver pristine digital-to-analog conversion, preserving the smallest details from low to high frequencies while ensuring ultra-low distortion and a wide dynamic range.
The K15 is one of the first audio products in the world to implement these flagship AKM chips in a dual configuration. FiiO claims they achieve an organic and immersive sound signature that preserves the musicality of recordings while revealing fine details.
Power Supply Options
The K15 features a high-efficiency 30W internal AC power supply but also supports 12V DC input for external linear power upgrades. It has independent digital and analog power rails with a multi-stage analog supply with multiple dropout regulators that guarantee a constant supply of clean current to each audio stage.
I am a sucker for diagrams, and this is the layout of the power supplies:
For those interested here are power plug specifications:
During operation, the K15 uses less power than the K17 while delivering excellent audio performance. Here is a breakdown off what I measured as far as usage:
Here is a comparison of the power draw from the K15 compared to the K17:
| Model | Idle (W) | Standby (W) | Switched On (W) | Playing Music (W) |
|---|---|---|---|---|
| K17 | 3.0 | 5.0 | 11.2 | 16.5 (HD600) |
| K15 | 1.9 | 2.5 | 4.8 | 13.5 (HD600) |
So, the K15 is much cheaper to run than the K17.
Powerful Amplification
The K15 features a discrete Class-AB amplifier circuit capable of delivering up to 3,000mW per channel via the balanced output. This provides more than enough power to drive demanding headphones with authority, from sensitive IEMs to high-impedance over-ear models.
To further protect the integrity of the signal, FiiO has used a tri-board design with separate digital, analog, and power supply sections spread across different circuits. Again, as I am a sucker for diagrams so this is one that FiiO provides:
This layout reduces the chance of crosstalk and electrical interference, resulting in an audibly cleaner sound.
User Interface and Control Options
A 3.93-inch color LCD touchscreen on the front panel provides visual controls, while tactile knobs offer quick access to key functions. For hands-free operation, there’s an infrared remote, and the FiiO Control app enables the unit to be controlled remotely.
Since the K15 has the same on-screen menu as the K17, please check out my K17 Review for full details on the onscreen menus and the ability to remotely control the K15 via the FiiO Music and FiiO Control Smartphone App.
Just like the K17, the menu system has been excellently designed and is intuitive and easy to navigate, with clear icons and logical organization.
Wireless Connectivity:
With Bluetooth 5.1 supporting multiple codecs (SBC, AAC, aptX, aptX LL, aptX HD, aptX Adaptive, and LDAC), the K15 ensures high-quality wireless audio. For network streaming, it offers both Gigabit Ethernet for lossless performance and dual-band Wi-Fi for wireless convenience.
Streaming Capabilities
The K15 supports multiple streaming options:
Roon Ready
For Roon subscribers, the K15’s native Roon support makes it a complete solution. Simply, link your streaming service
accounts within Roon, and you can enjoy a visually elegant and highly functional streaming experience.
Bluetooth and Airplay
The K15 supports high-quality Bluetooth codecs including LDAC and aptX HD, as well as Airplay for Apple users, making it easy to stream from mobile devices.
Local Playback
The K15 can play music files directly from a connected USB drive, with support for high-resolution formats up to 384kHz/32-bit and DSD256. The on-screen interface allows for browsing and playback control, while the FiiO Control app provides remote control capabilities that allow you to remotely browser the contents of the usb.
10-Band Parametric EQ
The K15 features a 10-band parametric EQ that can be controlled through the FiiO Control app. This allows for precise sound customization to match your preferences or to compensate for the characteristics of your headphones.
The FiiO Control app allows you to create and manage PEQ profiles:
You can rename custom profiles to match specific headphones or listening preferences:
You can save multiple EQ profiles for different headphones or listening scenarios, making it easy to switch between them using either the physical controls, the remote, or the app.
Desktop PEQ configuration:
The PEQ capabilities are slightly more limited on the K15 compared to the K17. However, I doubt if this affects anyone using the K15 as you still get 10 customizable preset slots, each with 10 Band PEQ that can be editable both within the FiiO App and also via Google Chrome on a PC and Macbook via USB serial connection using the FiiO Control software:
Note: This was the K15 USB serial connection name when I connected it into my computer to access the screen above:
Sound Impressions
The FiiO K15 delivers a transparent, detailed sound signature that serves as an excellent foundation for its PEQ capabilities.
Bass
The bass response is tight, controlled, and extends deep with excellent definition. There’s no artificial coloration or bloat in the low frequencies, allowing the natural bass character of your headphones to shine through. The powerful output ensures that bass notes have proper weight and impact, particularly with bass-heavy genres like electronic music and hip-hop.
When listening to tracks with substantial low-end content, the K15 maintains composure and control, preventing bass from becoming muddy or overwhelming the rest of the frequency spectrum.
Midrange
Vocals and instruments in the midrange are reproduced with exceptional clarity and natural timbre. The K15 presents the midrange with neither recession nor emphasis, allowing for an engaging and accurate listening experience across various genres.
Female vocals sound particularly impressive, with a smooth, natural presentation that avoids both the harshness that can occur with some DAC/Amps and the artificial warmth that others introduce. Male vocals have appropriate body and presence, while acoustic instruments sound realistic and well-textured.
Treble
The high-frequency reproduction is detailed and extended without becoming harsh or fatiguing. The K15 captures the shimmer of cymbals and the air around instruments with precision, avoiding both artificial brightness and rolled-off character.
The treble presentation strikes an excellent balance between detail retrieval and listening comfort, making the K15 suitable for extended listening sessions without fatigue.
Soundstage & Imaging
The K15 presents an impressively spacious soundstage with excellent separation between instruments. The clean output with low crosstalk contributes to precise imaging, allowing for accurate placement of sounds within the stereo field.
While the soundstage isn’t unnaturally wide, it extends beyond the confines of your head with headphones that are capable of good spatial presentation. The depth and height dimensions are also well-represented, creating a three-dimensional listening experience with appropriate recordings.
Specifications and Measurements
Here are the overall specifications:
| Specification | Details |
|---|---|
| Color | Black/Silver |
| Dimensions | 244.6 x 213 x 66.8mm |
| Weight | 2,100g |
| Master control | X2000, ESP32-S3 |
| DAC | AK4497S x 2 |
| USB | XMOS XU316 |
| Headphone amplifier transistor | MJE243G/253G |
| Display | 3.93-inch LCD |
| Bluetooth | 5.1 |
| Audio codecs | SBC/AAC/aptX/aptX LL/aptX HD/aptX Adaptive/LDAC |
| Decoding USB | 768kHz/32-bit; DSD512 (Native) |
| Coaxial input | 192kHz/24-bit; DSD64 |
| Optical input | 96kHz/24-bit |
| Local playback | 384kHz/32-bit; DSD256 |
| Streaming playback | 384kHz/32-bit; DSD256 (DOP) |
| RCA output | L+R=2.4Vrms+2.4Vrms (1kHz@10kΩ) |
| XLR output | L+R=4.8Vrms+4.8Vrms (1kHz@10kΩ) |
| Frequency response | 20Hz – 80kHz, attenuation < 2.8dB |
| SNR | ≥122dB (A-weighted) |
| Noise floor | <5.3μV (A-weighted) |
| THD+N | <0.00054% (1kHz/-12dB@32Ω) |
Headphone Output Performance
Just focusing on the headphone output:
6.35mm Single-Ended Output
| Specification | Ultra High Gain Mode | Super High Gain Mode |
|---|---|---|
| Output Power (16Ω) | L+R≥1400mW+1400mW (THD+N＜1%) | L+R≥1400mW+1400mW (THD+N＜1%) |
| Output Power (32Ω) | L+R≥1400mW+1400mW (THD+N＜1%) | L+R≥760mW+760mW (THD+N＜1%) |
| Output Power (300Ω) | L+R≥180mW+180mW (THD+N＜1%) | L+R≥90mW+90mW (THD+N＜1%) |
| Output Impedance | ＜1Ω (32Ω) | ＜1Ω (32Ω) |
| Crosstalk | ≥76dB (1kHz@32Ω) | ≥76dB (1kHz@32Ω) |
| THD+N | ＜0.00054% (1kHz/-12dB@32Ω) | ＜0.00058% (1kHz/-10dB@32Ω) |
| SNR | ≥122dB (A-weighted) | ≥119dB (A-weighted) |
| Noise Floor | ＜5.3μV (A-weighted) | ＜5.3μV (A-weighted) |
| Frequency Response | 20Hz |
20Hz |
| Peak Output Voltage | ＞20.6Vp-p | ＞14.6Vp-p |
4.4mm/XLR4 Balanced Output
| Specification | Ultra High Gain Mode | Super High Gain Mode |
|---|---|---|
| Output Power (16Ω) | L+R≥1400mW+1400mW (THD+N＜1%) | L+R≥1400mW+1400mW (THD+N＜1%) |
| Output Power (32Ω) | L+R≥3000mW+3000mW (THD+N＜1%) | L+R≥2800mW+2800mW (THD+N＜1%) |
| Output Power (300Ω) | L+R≥700mW+700mW (THD+N＜1%) | L+R≥350mW+350mW (THD+N＜1%) |
| Output Impedance | ＜1.5Ω (32Ω) | ＜1.5Ω (32Ω) |
| Crosstalk | ≥116dB (1kHz@32Ω) | ≥116dB (1kHz@32Ω) |
| THD+N | ＜0.00059% (1kHz/-13dB@32Ω) | ＜0.00054% (1kHz/-9dB@32Ω) |
| SNR | ≥120dB (A-weighted) | ≥120dB (A-weighted) |
| Noise Floor | ＜9.5μV (A-weighted) | ＜9.5μV (A-weighted) |
| Frequency Response | 20Hz |
20Hz |
| Peak Output Voltage | ＞41Vp-p | ＞29Vp-p |
Line and XLR Output Performance
| Output Type | Specification | Performance |
|---|---|---|
| Single-Ended (RCA) | THD+N | ＜0.00071% (1kHz/-11dB@10kΩ) |
| SNR | ≥119dB (A-weighted) | |
| Crosstalk | ≥119dB (1kHz@10kΩ) | |
| Noise Floor | ＜2.6μV (A-weighted) | |
| Output Level | 2.4Vrms (1kHz@10kΩ) | |
| Frequency Response | 20Hz |
|
| Balanced (XLR3) | THD+N | ＜0.00055% (1kHz/-8dB@10kΩ) |
| SNR | ≥120dB (A-weighted) | |
| Crosstalk | ≥117dB (1kHz@10kΩ) | |
| Noise Floor | ＜3.3μV (A-weighted) | |
| Output Level | 4.8Vrms (1kHz@10kΩ) | |
| Frequency Response | 20Hz |
Finally, I thought it might be interesting to do a comparison table with the K17:
FiiO K15 vs K17 Power Output Comparison
Headphone Single-Ended (6.35mm) Output
| Model | Gain Mode | 16Ω | 32Ω | 300Ω |
|---|---|---|---|---|
| K17 | Ultra High | 1800mW | 1850mW | 240mW |
| K17 | Super High | 1800mW | 1000mW | 120mW |
| K15 | Ultra High | 1400mW | 1400mW | 180mW |
| K15 | Super High | 1400mW | 760mW | 90mW |
Headphone Balanced (4.4mm/XLR4) Output
| Model | Gain Mode | 16Ω | 32Ω | 300Ω |
|---|---|---|---|---|
| K17 | Ultra High | 1800mW | 4000mW | 950mW |
| K17 | Super High | 1800mW | 3900mW | 480mW |
| K15 | Ultra High | 1400mW | 3000mW | 700mW |
| K15 | Super High | 1400mW | 2800mW | 350mW |
Line Output Performance
| Model | Output Type | Output Level | THD+N | SNR |
|---|---|---|---|---|
| K17 | RCA (Single-Ended) | 2.5Vrms | <0.00053% | ≥121dB |
| K17 | XLR3 (Balanced) | 5Vrms | <0.00045% | ≥125dB |
| K15 | RCA (Single-Ended) | 2.4Vrms | <0.00071% | ≥119dB |
| K15 | XLR3 (Balanced) | 4.8Vrms | <0.00055% | ≥120dB |
Key Differences Summary
- K17 advantages: Higher power at 32Ω single-ended (1850mW vs 1400mW), better balanced output at 300Ω, slightly better line output performance
- K15 advantages: More consistent power across impedance’s in ultra-high gain mode, slightly lower THD+N in some configurations
- Power difference: K17 delivers 29% more power at 32Ω single-ended and 33% more power at 32Ω balanced (ultra-high gain)
Rating
The FiiO K15 earns a 5-star Pragmatic Rating due to its exceptional value proposition, comprehensive feature set, and excellent sound quality.
Here’s the breakdown:
- Build Quality: ⭐⭐⭐⭐⭐ (Premium materials with the stunning retro design)
- Sound Quality: ⭐⭐⭐⭐⭐ (Transparent, detailed presentation with virtually no noise floor)
- Features: ⭐⭐⭐⭐⭐ (Comprehensive connectivity and PEQ capabilities)
- Measurements: ⭐⭐⭐⭐ (Excellent technical performance, though not quite at the level of the K17)
- Value: ⭐⭐⭐⭐⭐ (Exceptional value for the price)
The K15 is ideal for:
- Audiophiles seeking a high-performance DAC/Amp solution without breaking the bank
- Users who want comprehensive connectivity options for various audio sources
- Those who appreciate both technical excellence and aesthetic design
- Anyone looking to drive a wide range of headphones from a single device
- Music lovers who value a clean, transparent sound signature that lets their headphones shine
Conclusion
The FiiO K15 represents an incredible achievement in value-oriented high-end audio. By taking most of the best aspects of the K17, the looks, most of the power, the inputs and outputs, and the features like streaming and PEQ and providing them in a much more affordable package, FiiO has created a product that will satisfy even demanding audiophiles at a very pragmatic price.
The compromises FiiO has made—using the slightly less expensive AK4497S DAC chips but newer, reducing the maximum power output somewhat, and limiting the PEQ to 10 bands instead of 31—are thoughtfully chosen to minimize the impact on real-world performance. For the vast majority of users and headphones, these differences will be negligible in practice.
What’s particularly impressive is how the K15 maintains the premium feel and user experience of its more expensive sibling. The build quality, interface, and overall design language remain intact, creating a cohesive product that never feels like a “budget” option.
For those who have been eyeing the K17 but found it beyond their budget, the K15 represents an opportunity to get most of the way there at a significantly lower price point.
In a market where true value is often hard to find, the FiiO K15 stands out as a pragmatic choice that delivers performance well beyond its price point. It’s not just a great value—it’s a genuinely excellent product in its own right.