A "Hearty" Benchmark New Paradigm

The M21 redefines the entry-level class with its flagship lineage, Its internal and external "hearts" are full of "heart" in providing you with enjoyment. Its compact screen and class-defying performance are a massive step forward, Aiming to be a benchmark for an entirely new generation.

Flagship Soc a New Entry-level Benchmark

The Qualcomm Snapdragon 680 has superior performance with less power consumption than the SoCs used by players in the same class. It provides a smooth experience with Android 13.

4xCS43198 Full of "Hearty" Power

The four DAC chips allow for an eight-channel fully differential output design, fully unleashing the potential of headphones with class-defying dynamic performance and high anti-interference capabilities. The headphone amplifier section adopts a two-stage circuit design: the first stage is responsible for voltage amplification, while the second stage handles current expansion - all ensuring purer sound with rich detail.

Patented Desktop Mode Battery Protection Expert

Desktop mode makes an appearance on an entry-level FIlO player for the first time. When desktop mode is enabled, the M21 is completely powered by an external power supply. The built-in battery is neither charged nor discharged, allowing you to use the plaver safely on the desktoo without dearading its battery.

Portable/Desktop Dual Power Supply Modes a Jump in Performance

In portable mode, it operates with standard voltage power supply. When using the external power "Super high gain" mode, the player automatically switches to using a high-voltage power supply with 21Vpp (3002) peak drive voltage and 950mW (322) massive output power. This delivers desktop-level power output, making the player a better fit with a wider range of earbuds or headphones for a truly extraordinary auditory feast.

Go Back to the Walkman Era With Just One Touch

The custom cassette-style protective case* paired with an exclusive retro Ul and tailored vintage sound effects all take you on a nostalgic journey back to the Walkman era. Remove the protective case to seamlessly switch back to the original system, giving you the flexibility to use it how you want to.

True Quality Inside and Out

The fully aluminum alloy body with an AG frosted glass back offers a delicate texture and comfortable grip. The screen features an oleophobic coating that significantly reduces fingerprints and smudges, making for smoother touch operation.

Digital and Analog Partition Shielding Purely Heavenly Sound

The digital and headphone amplifier sections exist in separate partitions and each is equipped with independent shielding covers for isolation. This not only further reduces signal crosstalk but also enables efficient heat dissipation, delivering purer sound.

Flagship-Grade Power

There are separate power supply paths for thedigital and analog circuits, which effectively reduce crosstalk between the two. The result is more precise digital processing, purer analog output, and enhanced driving power. The analog circuit isfurther subdivided into multiple independent power supplies for components such as the DAC and headphone amplifier. This clean and robust power delivery enhances the dynamic range and leads to greater reproduction of details in the audio - for a more refined and natural sound.

High-End Hifi Parts for Better Sound

In the M21's audio circuit are high-precision thin-film resistors and low-temperature-drift capacitors that ensure refined and stable sound quality - specifically the greater consistency between the left and right channels and across all frequency ranges. Additionally, fine circuits such as the DAC and headphone amplifier are equipped with over 10 low-impedance, high-capacity tantalum capacitors. These provide abundant energy reserves and a robust power supply for more powerful, dynamic sound.

Global Audio Optimization

FIlO developed a custom crystal oscillator specifically for the M21, which has been carefully selected to meet femtosecond-level standards, in order to ensure consistency and stability in its output. With a high-precision, low-jitter unified clock source, it accurately matches PCM and DSD audio at various sampling rates, ensuring precise reproduction of digital audio signals.

Digital Output

SPDIF output: The low-jitter coaxial output is comparable to that of pro equipment, with the jitter reduced by 70% and achieving high performance when connected to an external high-end audio DAC.

USB Audio Output

Connect to an external audio DAC and instantly turn it into a streaming jukebox.

15h Long Battery Life Exploring The World of Music

The M21's 4000mAh high-voltage battery provides up to 15 hours of ultra-long battery life, effortlessly providing the energy for extended listening sessions when commuting or traveling, allowing you to fully immerse yourself in the world of music. It also supports 20W PD fast charging, enabling quick recharges even during short breaks.

Specifications:

General Specifications:

• Name/Model: M21
• Hardware Solution: SoC: Qualcomm Snapdragon 680, DAC: CS43198 ×4, Amp: OPA1692 ×2 + SGM8262-2 ×2
• Working Mode: Android / Pure Music / AirPlay / USB DAC / Bluetooth Receiving
• Weight: About 193g
• Dimensions: About 68 × 121 × 17 mm
• Volume Control Type: Button Control
• Display: 4.7-inch (750 × 1334) bezel-less screen
• Internal Storage / Available Capacity (ROM): 64GB / About 52GB
• RAM: 4GB
• Memory Card: Single microSD card expansion, up to 2TB (in theory)
• Adaptive Impedance:
  • PO: 8 ~ 350Ω
  • BAL: 8 ~ 350Ω
• Channel Balance: L20 ~ R20 (0.5dB per level)

Buttons and Ports:

• Buttons: Power button ×1; Multifunction button ×1; Volume buttons ×2; Play/Pause button ×1Previous track ×1; Next track ×1
• Toggle Switch: HOLD switch ×1; D.MODE switch ×1
• USB: Type-C USB 3.0 ×1 (charging/data transmission) + Type-C POWER IN ×1
• Headphone Out: Standard 3.5mm
• Line Output: Standard 3.5mm (shared PO)
• BAL Headphone Out: Standard 4.4mm
• BAL Line Output: Standard 4.4mm (shared BAL)
• COAX Headphone Out: Standard 3.5mm (shared PO)
• Exposed Contacts: Connect to cassette-style protective case

Special Functions:

• WiFi: 2.4GHz / 5GHz, supports DLNA, AirPlay, WiFi song transfer, Roon Ready, etc.
• Bluetooth Transmission (5.0): AAC, SBC, aptX, aptX HD, LDAC, LHDC
• Bluetooth Reception (5.0): SBC, AAC, LDAC
• FIIO Link: Android supports WiFi and Bluetooth control; iOS supports Bluetooth control
• MQA: Supports MQA full decoding
• ALL TO DSD: Supported
• EQ Adjustment: 10-band dynamic EQ adjustment (±12dB), 8 built-in preset EQs, user-defined Esupported
• System Navigation Mode: Gesture navigation, 2-button navigation, 3-button navigation
• Double Tap to Wake Up: Supported
• Power Off Timers: Supports Sleep / Idle power off
• Max Supported Sampling Rate:
• USB DAC: Up to 384kHz/32bit; DSD256 (Native)
• Local Decoding: Up to 384kHz/32bit; DSD256 (Native)
• USB Audio: 768kHz/32bit; DSD512 (DoP / D2P / Native)
• Coaxial Output: Up to 384kHz/24bit; DSD128 (DoP)
• Firmware Upgrade: Supports upgrades via local storage, memory card, and OTA

Power & Battery:

• Power Supply: Supports D2.0 and PD3.0 fast charging
• Charging Time: About 1.5 hours (PD3.0 fast charging mode)
• Battery Life and Test Conditions:
• 3.5mm Headphone Out: 15 hours
• Volume Level: 44
• Gain Level: High Gain
• Display Status: OFF
• Track & Format: MP3 44kHz / 16bit
• EQ: OFF
• Load: 32Ω
• 4.4mm Headphone Out: 12.5 hours
• Volume Level: 33
• Gain Level: High Gain
• Display Status: OFF
• Track & Format: MP3 44kHz / 16bit
• EQ: OFF
• Load: 32Ω

Audio Parameters:

Parts of performance and parameters of PO (3.5mm, USB DAC, Super High Gain mode):

• Output Power:
• L+R ≥ 480mW + 480mW (16Ω, THD+N < 1%)
• L+R ≥ 405mW + 405mW (32Ω, THD+N < 1%)
• L+R ≥ 45mW + 45mW (300Ω, THD+N < 1%)

• Output Impedance: < 1Ω
• Crosstalk: ≥ 74dB
• Peak Output Voltage: 10.6Vp-p
• SNR: ≥ 124dB (A-weighted)
• THD+N: < 0.0003% (1kHz / -4dB @32Ω)
• Frequency Response:
  • 20Hz ~ 85kHz: attenuation < 2dB
  • 20Hz ~ 20kHz: attenuation < 0.02dB

• Noise Floor: < 2uV (A-weighted)
• Dynamic Range: ≥ 124dB (A-weighted)

Parts of performance and parameters of PO (3.5mm, USB DAC, High Gain mode):

• Output Power: L+R ≥ 380mW + 380mW (16Ω, THD+N < 1%)
• Output Power: L+R ≥ 290mW + 290mW (32Ω, THD+N < 1%)
• Output Power: L+R ≥ 35mW + 35mW (300Ω, THD+N < 1%)
• Output Impedance: < 1Ω
• Crosstalk: ≥ 74dB
• Peak Output Voltage: 9.5Vp-p
• SNR: ≥ 123dB (A-weighted)
• THD+N: < 0.0004% (1kHz/-4dB@32Ω)
• Frequency Response:
  • 20Hz ~ 85kHz: attenuation < 2dB
  • 20Hz ~ 20kHz: attenuation < 0.02dB

• Noise Floor: < 2.1uV (A-weighted)
• Dynamic Range: ≥ 123dB (A-weighted)

Parts of performance and parameters of LO:

• THD+N: < 0.0005% (1kHz/-5dB@10KΩ)
• SNR: ≥ 122dB (A-weighted)
• Crosstalk: ≥ 111dB
• Noise Floor: < 1.6uV (A-weighted)
• Frequency Response:
  • 20Hz ~ 85kHz: attenuation < 1.8dB
  • 20Hz ~ 20kHz: attenuation < 0.02dB

• Line Output Level: 1.9Vrms
• Dynamic Range: ≥ 122dB (A-weighted)

Parts of performance and parameters of BAL headphone out (4.4mm, USB DAC, Super High Gain mode):

• Output Power: L+R ≥ 540mW + 540mW (16Ω, THD+N < 1%)
• Output Power: L+R ≥ 950mW + 950mW (32Ω, THD+N < 1%)
• Output Power: L+R ≥ 185mW + 185mW (300Ω, THD+N < 1%)
• Output Impedance: < 1.5Ω
• Crosstalk: ≥ 109dB
• Peak Output Voltage: 21.2Vp-p
• SNR: ≥ 126dB (A-weighted)
• THD+N: < 0.0005% (1kHz/-12dB@32Ω)
• Frequency Response:
  • 20Hz ~ 85kHz: attenuation < 2dB
  • 20Hz ~ 20kHz: attenuation < 0.03dB

• Noise Floor: < 2.7uV (A-weighted)
• Dynamic Range: ≥ 125dB (A-weighted)

Parts of performance and parameters of BAL headphone out (4.4mm, USB DAC, High Gain mode):

• Output Power: L+R ≥ 600mW + 600mW (16Ω, THD+N < 1%)
• Output Power: L+R ≥ 720mW + 720mW (32Ω, THD+N < 1%)
• Output Power: L+R ≥ 90mW + 90mW (300Ω, THD+N < 1%)
• Output Impedance: < 1.5Ω
• Crosstalk: ≥ 109dB
• Peak Output Voltage: 15Vp-p
• SNR: ≥ 125dB (A-weighted)
• THD+N: < 0.0005% (1kHz/-8dB@32Ω)
• Frequency Response:
• 20Hz ~ 85kHz: attenuation < 2dB
• 20Hz ~ 20kHz: attenuation < 0.03dB

• Noise Floor: < 2.7uV (A-weighted)
• Dynamic Range: ≥ 124dB (A-weighted)

Parts of performance and parameters of BAL LO:

• THD+N: < 0.0003% (1kHz/-0dB@10KΩ)
• SNR: ≥ 126dB (A-weighted)
• Crosstalk: ≥ 103dB
• Noise Floor: < 1.9uV (A-weighted)
• Frequency Response:
  • 20Hz ~ 85kHz: attenuation < 1.8dB
  • 20Hz ~ 20kHz: attenuation < 0.02dB

• Line Output Level: 3.9Vrms
• Dynamic Range: ≥ 125dB (A-weighted)