FiiO SnowSky OAK NANO

In-ear headphones with a dynamic driver

• Beryllium-coated driver
• Pure titanium housing, CNC-machined
• Cryogenically treated, silver-plated single-crystal copper cable
• Dynamic driver with a 13.8 mm outer diameter
• W-shaped diaphragm with independent surround
• Acoustic prism front chamber
• Airflow-controlled, damped rear chamber
• Two interchangeable tuning nozzles
• Includes interchangeable plugs (3.5 mm/4.4 mm/TC)
• 0.78 mm 2-pin detachable cable
• Hi-Res Audio certified

Ultimate elegance – a new movement in sound

The History of the OAK Series

The new OAK series pays homage to the timeless craftsmanship of Audemars Piguet. We honor the watchmaker’s pursuit of perfection and translate this dedication into rock-solid build quality and an elegance that never fades. Where sound meets light, individuality and sophistication take center stage.

OAK NANO is the first model in the OAK series, the spiritual successor to the FIIO FD7, and SNOWSKY’s first flagship product. The OAK NANO is the result of two years of research and development—a journey of ceaseless refinement in pursuit of jewelry-grade craftsmanship and an exceptional sonic character. The development team chose beryllium metal for the diaphragm—the same premium material found in the FD7. Its rare combination of lightness and rigidity ensures a distinctively clear and open sound character. Together with a series of sophisticated acoustic innovations, the OAK NANO transforms every listening session into a first-class audio experience.

High-Quality Materials – Sublime Sound Fidelity

Beryllium Alloy Diaphragm

The OAK NANO inherits the acoustic DNA of the legendary FIIO FD7 and carries on the legacy of beryllium diaphragms while breaking new ground. As a driver material, beryllium is ultra-light, exceptionally rigid, and superior to aluminum or titanium. Its low damping and high sound velocity ensure no unwanted coloration, making it the top choice for high-end audio.

While pure beryllium is becoming increasingly rare due to global supply chains, the OAK NANO utilizes a special beryllium alloy that mirrors the performance and sonic characteristics of the pure metal. FiiO has pushed the boundaries of precision engineering to reduce the thickness of the diaphragm and thus further exploit the material’s potential. This significantly improves high-frequency reproduction, transient response, and distortion control, enabling the precise reproduction of the finest details—from the crisp attack of percussion to the delicate nuances in vocals.

Refined Sophistication – Timeless Elegance

Pure Titanium Housing

The OAK NANO utilizes pure titanium, prized for its density and hardness, to create a housing that remains flawless over time. Through a series of sophisticated and precise manufacturing processes, including mirror polishing, CNC machining, and PVD coating, its distinctive design language comes to life, showcasing the headphones’ unique color, luster, and sharp contours with impressive clarity.

The conductor reimagined – The next level of sonic purity

-192 °C cryogenically treated with liquid nitrogen, silver-plated single-crystal copper cable

FiiO selects 6N OCC (99.99998% pure) single-crystal copper as the raw material. This ultra-high-purity conductor is naturally free of grain boundaries and offers exceptionally low resistance and high conductivity, while eliminating oxygen and hydrogen impurities that compromise signal integrity.

To push electrical performance to its absolute limit, each conductor undergoes a 168-hour (7 full days) deep cryogenic treatment.

At -192 °C, internal stresses in the metal are completely relieved, allowing the atomic structure to rearrange itself and form a more uniform, denser arrangement. This molecular restructuring ensures a more uniform flow of electrons, resulting in a remarkably clear and fluid sound—free from the harshness or “graininess” often found in standard cables.

High-flux-density magnetic control – Unleashed dynamic power

13.8-mm dynamic driver with external magnet

Building on the legacy of the FD7, the OAK NANO features a larger 13.8-mm driver unit with a correspondingly enlarged and thickened magnet. A larger magnet means a stronger and more stable magnetic field. Laboratory tests confirm that the magnetic flux density in the voice coil gap reaches nearly 1.5 T, with distortion of only 0.1% even at 114 dB SPL. This immense magnetic force provides the necessary driving power for greater amplitude and minimal vibration distortion, resulting in outstanding transient response.

*Test data from FIIO Acoustic Labs

Tailor-made – Excellence in Every Detail

Advanced dynamic driver design

Starting with the acoustic characteristics of a single dynamic driver, FiiO spared no effort in refining the OAK NANO’s diaphragm, magnetic system, and voice coil—every detail is a deliberate step toward higher performance and a more refined sound.

-Diaphragm thickness -50%

Lighter, stronger beryllium dome tweeter

In the pursuit of perfection, FiiO has achieved the impossible: a larger beryllium dome that is simultaneously significantly thinner. Combined with FiiO’s newly developed high-flux magnetic circuit, the OAK NANO achieves lightning-fast transient response and breathtaking high-frequency reproduction.

-Effective vibrating area +30%

W-shaped independent surround

Inspired by high-end home audio systems, the OAK NANO features a separate beryllium dome and a beryllium-coated suspension design that eliminates the weaknesses of conventional diaphragms. The result is a 30% larger effective diaphragm area and significantly greater energy reserves. Experience sound that is beautifully textured and undeniably powerful

-Magnetic flux density 1.5 Tesla

1.5-T high-flux external magnet design

With a dynamic headphone, everything begins and ends with the driver. The OAK NANO features a magnetic flux density of 1.5 Tesla, which significantly improves conversion efficiency and driver control. This high-flux environment effortlessly drives the diaphragm, resulting in a remarkably full-bodied and authoritative sound.

-Pure Copper CCAW Voice Coil

Refined High-Frequency Soundstage

Specially Selected Pure Copper Voice Coil

While conventional single-driver designs often use lightweight copper-clad aluminum (CCAW) to enhance detail, the OAK NANO takes a more refined approach. Since our beryllium dome naturally offers high resolution in the high-frequency range, we opted for a pure copper voice coil to balance the sound character.

This choice lends the sound a rich, soft warmth and a gentle, organic timbre—resulting in a deeply emotional and fatigue-free listening experience.

Precision Correction – The Sound Stays on Track

Acoustic Prism System in the Front Chamber

The OAK NANO utilizes an advanced Acoustic Prism to ensure your music stays “on track.” This technology, proven in the acclaimed FD7, corrects the phase of sound waves as they travel through the chamber. By eliminating time delays and standing wave distortions, it enables superior control over every frequency, resulting in a refined sound.

Precise airflow control – transformed mids and bass

Airflow-controlled, damped rear chamber

Using micro-precise CNC machining, a high-density acoustic damping grid has been integrated into the vent openings of the OAK NANO’s rear chamber to regulate internal airflow. This special damping effectively suppresses resonances, resulting in deeper and more impactful bass. The midrange also benefits, with noticeable improvements in richness and density in the 100 Hz to 4 kHz range. The result is a fuller, more satisfying midrange and bass across the board.

Two sound profiles – Discover a new sound at any time

Two interchangeable tuning nozzles

The OAK NANO features interchangeable tuning nozzles, including both red and black acoustic filters, to offer advanced tuning options. Each tuning nozzle features different densities of damping material to offer a total of two distinct sound profiles that match your personal listening preferences.

Red nozzle

Master of atmosphere. Deep, present bass foundation with a powerful sense of space. Perfect for pop, rock, and folk.

Black Tip

Precise and detailed. Crystal-clear transparency with bright, detailed high-frequency reproduction. Perfect for classical and instrumental music.

Seamless compatibility – tailored to your needs

Detachable cable and interchangeable plugs

The OAK NANO was designed for ultimate flexibility. With a fully detachable cable and an interchangeable connector system, it effortlessly adapts to any listening environment. The package includes three interchangeable connectors to cover all your devices. Of particular note is the Type-C connector, which unlocks a variety of real-time adjustment options—giving you the flexibility of multiple setups in a single device.

3 interchangeable connectors

8-band precision PEQ

The OAK NANO comes standard with 3.5mm single-ended, 4.4mm balanced, and Type-C DSP connectors for digital decoding.

The Type-C connector houses a BES3001-SP DSP audio decoding chip with a balanced output, supporting the decoding of high-resolution 32-bit/384 kHz PCM audio as well as an 8-band precision PEQ setting. Thanks to FIIO’s proprietary algorithm and access via the FIIO Control app or web interface, users can effortlessly customize, export, and save custom audio curves.

* Web PEQ access: Official FIIO website > Support > Web-based PEQ settings.

*The Type-C connector does not currently support UAC 1.0 (e.g., Xbox, Switch, and PlayStation consoles).

* Support for the FIIO Control App is currently limited to Android; iOS is not yet supported.

0.78 mm 2-pin detachable cable

This widely used connector offers comprehensive compatibility with a variety of aftermarket cables. The robust 2-pin design ensures a secure fit and provides an absolutely stable connection for an uninterrupted signal path.

Premium Accessories – Exceptional Standards

22 ear tips and a custom-designed carrying case

True to our commitment to always go the extra mile, the OAK NANO comes standard with 22 pairs of ear tips in various designs, as well as a newly designed carrying case. Everything you need, right out of the box—no additional purchases required.

22 pairs in 3 different earbud designs

-FIIO HS20

Made from high-quality silicone that highlights the warmth of vocals and the depth of low frequencies. With German LFGB certification for food-grade quality, it sits comfortably and securely in the ear—soft, breathable, and gentle on the skin.

-FIIO HS18

Designed with a wide opening that matches the nozzle size of the OAK NANO for direct, unobstructed sound transmission. Thanks to its ultra-thin 0.4 mm flange, it is virtually invisible when worn.

-SpinFit CP360

Features medical-grade silicone and a unique swivel design that adapts to your individual anatomy, ensuring a secure, comfortable fit.

-Custom-made carrying case

This carrying case, crafted exclusively for the OAK NANO, combines an aluminum alloy with PU leather, offering a understated yet sophisticated design with an unmistakably premium feel.

The Gold Standard of Sound Fidelity – Officially Recognized

Hi-Res Audio Certified

OAK NANO has met the certification standards for high-fidelity audio established by the Japan Audio Society and the Consumer Electronics Association—a trusted seal of quality that guarantees faithful sound reproduction.