FiiO M15S – High-Res DAP with ES9038PRO, Android & Desktop Mode
- 2 reviews
- Fiio
Description
FiiO M15S Desktop/Portable Hi-Res Digital Audio Player
The Power of a Desktop Setup. The Freedom of a Portable Player.
The FiiO M15S is an evolution of the classic M15, engineered to blur the line between portable convenience and desktop performance. It acts as a pocket-sized powerhouse, delivering the robust energy required to drive demanding over-ear headphones while remaining compact enough for your daily commute.
Powered by the legendary ESS ES9038PRO DAC (a chip typically found in high-end desktop equipment), the M15S offers an uncompromised listening experience with elite-level resolution and dynamic range.
Key Features & Highlights
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Desktop/Portable Dual Power Supply Modes: This is the game-changer. When connected to the included fast-charging adapter or the DK3S dock, the M15S activates "Desktop Mode," bypassing the battery to deliver a massive 1200mW+1200mW output power. It drives hard-to-power headphones (like the Sennheiser HD600/800s) with ease.
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Flagship ES9038PRO DAC: Utilizes the 8-channel desktop DAC chip for ultra-low distortion (THD+N <0.0003%) and a pristine noise floor. Every detail of your music is rendered with crystal clarity.
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Snapdragon 660 & Android 10: Experience a lag-free, smartphone-like interface. Install your favorite streaming apps—Spotify, Tidal, Qobuz, Apple Music—and enjoy bit-perfect playback thanks to FiiO's global SRC bypass.
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Five Gain Levels: From "Low" for sensitive IEMs to "Super High" for planar magnetic headphones, the M15S adapts to your entire gear collection.
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Full Wireless Capability: Supports two-way Bluetooth 5.0 with high-res codecs (LDAC, aptX HD, aptX Adaptive) and dual-band WiFi for seamless streaming and Roon Ready integration.
Why Choose the FiiO M15S?
1. No More "Stacking" Required
Audiophiles often carry a DAP strapped to an external amplifier to get enough power. The M15S eliminates this bulk. Its internal amp is powerful enough to stand alone, giving you a clean, one-device solution.
2. Advanced Heat Dissipation
High power means heat. The M15S uses a stainless steel battery compartment and graphene heat dissipation technology to keep the device cool, ensuring consistent performance even during long listening sessions in High Gain mode.
3. A Visual & Tactile Joy
Features a classic volume knob with an RGB indicator light, a responsive 5.5-inch HD display, and a "dragon scale" textured rear panel that feels premium in the hand and resists fingerprints.
Technical Specifications
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SoC: Qualcomm Snapdragon 660
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DAC Chip: ESS ES9038PRO
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Screen: 5.5-inch (1440x720) Touchscreen
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Output Power: Up to 1200mW (32Ω, Balanced, Ultra High Mode)
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Outputs: 3.5mm Single-Ended / 2.5mm Balanced / 4.4mm Balanced
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Battery: 6200mAh (Quick Charge 3.0/4.0 support)
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OS: Android 10 (Open System)
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MQA Support: 8x Unfolding
What's in the Box:
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FiiO M15S Player x1
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DK3S Heat Dissipation Dock x1
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Leather Case x1
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USB Power Cable & Data Cable x1
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Quick Start Guide x1
Specifications
- Weight: 200gr
- Usage: Indoor & outdoor
Pros and cons
- Sustainably produced
- Ideal for everyday use
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Portable Hi-Res Lossless Music Plaver
Desktop/portable dual power supplies | High-performance ES9038PRO DAC
QCC5124 with full Bluetooth format support | Qualcomm 660+Android 10
1200mW+1200mW continuous output power | Dk3s dock included
Five gain levels| Six operating modes including Roon Ready -
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Pocket Desktop-Level MachineM15S
The "deskton/portable dual power supply modes" as featured on the porable desktop-arade plaver M17 and the
portable desktop-grade amp Q7 have been well-received by the audiophile community, which is why we sought to
put this technology on other products.Now with the implementation of the dual power supply modes onto the M15
with its more eraonomic desian, the M15S is the ideal combination of portability and hiah performance.
Flagship-level tech
A new chapter in the high-end
The new M15S starts a new chapter in the Fii0 high-end, sharing the
same technologies as the portable desktop-grade M17 player and the
portable desktop-grade amp Q7 that give you desktop-level
performance in a portable package-including desktop mode, dual
power supply modes, and five gain levels.
Dedicated desktop mode
When in the dedicated desktop mode and under USB fast charging, the
M15S will transform essentially into a desktop device and work
completely without the battery. That is, under this mode the battery will
neither be charged nor discharged, preventing premature battery
degradation.
Desktop/portable dual
power supply modes
Robust performance everywhere
The M15S not only features the “desktop/portable dual power supplies”
as seen in other FiiO products, it is also equipped with an automatic
*auxiliary DC power supply”-the M15S is able to automatically
recognize when fast charging* through USB is being used and
automatically switches to use the highest-voltage power supply, leading
to an increase of 26.67% in power supply for even more power output.
Even when not using the fast-charging adapter, the M15S can still
automatically switch to a higher-voltage power supply that is enough to
drive most headphones.
*Activated as soon as it detects QC/PD fast charging through USB
26.67%
Power supply increase
21.21%
Power output increase
Five gain levels
Near-desktop power
The M15S can be adjusted with five levels of gain.Under battery
power, low/medium/high/over-ear headphone gain levels can be
selected.When under USB power, the enhanced over-ear headphone
gain level is also available, enabling undistorted power output up to
1200mW per channel, easily enough to drive a wide variety of lEMs
and headphones.
Six operating modes
including Roon Ready
Pure Music mode: Fii0 exclusive mode, for immersive music.
Android mode: Freely use third-party apps, including those of
streaming services.
AirPlay mode: wirelessly connect to iOS devices like iPhone/iPad,
with a sound quality boost.
Roon Ready mode: Roon Ready certified, for serious music lovers.
USB DAC mode: acts as a DAC when connected to a
computer/phone, for greatly improved sound.
Bluetooth receiver mode: supports SBC, AAC, aptX, aptX HD, aptX
LL, LDAC, and aptX Adaptive, for convenient quality wireless sound
Overbuilt power supply
For ample clean power anytime
Fully separated digital power supply, effectively reducing crosstalk and
interference. Multi-stage analog power supply, high-precision and low-noise for early
signal processing. Multi-voltage servo power supply for headphone amp, capably
driving low and high-impedance loads
High-performance ES9038PRO DAC
Desktop-grade part
The full, uncut desktop ES9038PRO DAC chip with eight independent D/A converters is
employed in the M15S.Each channel uses four D/A converters in parallel to form a fully
differential output, for a truly rich and highly resolving sound
4th-gen FPGA+NDK femtosecond crystal
DAPs Digital Audio Purification System
Audio data is passed through a Fii0-developed 4th-gen FPGA with phase-locked loop technology, which works
together with two custom Japanese NDK femtosecond crystal oscillators to provide a high-precision and low
jitter unified clock source for the entire audio architecture. This is all done in the pursuit of purer sound.
Multi-stage audio circuit
For faithful sound reproduction
The M15S features a multi-stage audio circuit complete with IV, LPF, gain adjustment
and amplifier sections. High-precision and low-noise film resistor used ensures more
accurate signal reproduction and channel balance. Within the LPF part of the circuit
are Panasonic low-loss metalized film capacitors that guarantee extremely low
harmonic and phase distortion.
Graphene heat dissipation technology
Cooling for consistent high-power output
Advanced and highly efficient heat dissipation design allows the M15S to
maintain stable temperatures and continuously deliver high power output:
Stainless steel battery compartment, to quickly dissipate battery heat;
Low temperature-drift and high-precision thin-film resistors and capacitors,
that can stably cope with temperature swings,
A dedicated metal shield, graphene, and high thermal conductivity silica gel
over hotspots for maximum heat dissipation.
Comprehensive shielding
For truly“clean” sound
In order to shield from interference as much as possible, the M15S
employs a nickel copper shield that shields the analog portion of
the audio circuit as well as the main SoC to ensure the purity of
the analog signals traveling through the circuit. In addition,
stacked onto the main shield are other heat dissipation and
shielding materials as well as wave-absorbing paper. The high-
quality parts and carefully-considered shielding design all aim to
ensure truly clean and highly-resolving sound.
Wireless HiFi taken to the next level
SBCIAAClaptX/aptX HDl DAc 2-way
The M15S wireless capabilities include AirPlay, LNA streaming and transmission, as well as
Bluetooth. Bluetooth is handled by the Qualcomm QCC5124 chip that has a proven track
record in other Fii0 products, allowing the M15S to capably handle 2-way Bluetooth.
Bluetooth 5.0 supported transmission: SBC, AAC, aptX, aptX HD, LDAC, LHDC
Bluetooth 5.0 supported reception: SBC, AAC, aptX, aptX HD, aptX LL, LDAC, aptX Adaptive
Knob/button volume adjustment
Reliable and easy to use
Volume on the M15S can be adjusted either with an analog potentiometer knob or with
buttons, both easily allowing you to fine-tune through the 120 levels of volume the way
you prefer.
Feel free to turmn the volume knob to your heart's content, as the integrated rotary
encoder* is highly precise and des gned for minimal wear with each turn of the knob.
Even if you accidentally drop the device, the encoder is securely fixed ensuring the
continued reliability of the volume knob.
*The volume knob features RGB lights, which can be customized in brightness, color, and behavior
under various device statuses. *Encoder rated durability>30000 cycles (360° forward
rotation+360° reverse rotation is 1 cycle)
Qualcomm 660+Android 10
A match made in heaven
With the stable and smooth combination of the Qualcomm Snapdragon 660 and
Android 10, you can start listening quickly with the M15S.With the ability to freely
install third-party apps and with no global SRC, you can be sure to listen to the music
you want in the highest quality.
Elegantly constructed
Instantly mesmerizing
The M15S features a combination of classical timeless
styling and modern technological touches that give it an
elegant appearance that is enjoyable to use.
*3.5mm single-ended headphone output, with line out and coaxia!
out support *4.4mm balanced headphone output, with balanced
2.5mm
balanced headphone output
3.5mm
single-ended headphone output
4.4mm
balanced headphone output
Long battery life
For worry-free use
Despite its portable size, the M15S features a high-capacity
battery that ensures all-day listening whether you are using single-
ended or balanced output.Battery charge optimization and battery
protection systems are there to ensure that the battery will last for
About3.5h
Charging time
oc3.0+PD
Fast charging protocols
9h/10.5h
Battery life
More safeguards
Fewer headaches
The overheat protection and battery protection systems are
among the many safeguards that ensure the M15S can
consistently maintain its high power output, letting you listen with
fewer headaches.
Temperature protection: The M15S regulates itself to be within
an optimal temperature range no matter the environmental
conditions, including stopping battery charging if necessary.
Optimized battery charging: in desktop mode, the M15S can be
used without going through the battery. When not in desktop
mode, the M15S can be placed in an “optimized battery charging
mode that prevents the battery from being charged all the way to
100% to prevent premature battery degradation.
Rich functionality A true all-in-one
parameters
General Specifications
Name/Model
M15S
working mode
Android mode/Pure music mode/USB DAC mode/Bluetooth receiving mode/AirPlay mode/Roon Ready
color
Black
Size
about 140x80x18.9mm
screen
5.5-Inch full-fit screen (resolution 1440 * 720)
RAM
4GB
Storage expansion
Single TF card slot, up to 2TB (theoretically)
Hardware
Soc: Snapdragon 660, DAC: ES9038PRO, Amplifier: OPA926 * 2, Crystal Oscillator: NDK Femtosecond Crystal Oscillator * 2
Weight
about 345g
Volume Control Type
button control or knob control
Body Memory/User Free Space (ROM)
64GB/About 46GB
Gain
Ultra high (Quick charge)/Super high/high/medium/low
Recommended headphone impedance
8 ~ 150Ω (single-ended output)/8 ~ 350Ω (balanced output)
Channel balance
L20~ R20 (0.5dB per level)
Buttons and interfaces
Button
Physical key
Headphone output
3.5mm single-ended
Balanced output
2.5mm + 4.4mm balanced
coaxial interface
3.5 mm (shared with PO port, up to 384kHz-32bit/DSD128)
USB
TYPE C USB3.0 (charging/data transmission)
Line output port
3.5 mm (shared with PO port)
Balanced line output interface
2.5mm balance + 4.4mm balance (shared with PO ports)
Features
WiFi
2.4GHz/5GHz, supports DLNA transmission and reception, AirPlay, WiFi transmission, Roon Ready, etc.
Bluetooth reception (5.0)
SBC, AAC, aptX, aptX HD, aptX LL, LDAC, aptX Adaptive
MQA
Global 8x decoding
Double click to wakeup
support
Maximum supported sampling rate
Native: Up to 384kHz-32bit/DSD256 / USB DAC up to 384kHz-32bit/DSD256
Power-off timer
Support power saving shutdown/sleep shutdown
Firmware Upgrade
Support local storage upgrade + TF card local upgrade + OTA push upgrade
Bluetooth Transmitter (5.0)
SBC, AAC, aptX, aptX HD, LDAC, LHDC
FiiO Link
Android support WiFi and Bluetooth control, iOS support WIFI control
All to DSD
support
USB Audio
768kHz-32bit/DSD512 (DoP/D2P/Native)
Car mode
can follow the car USB automatic switch machine
EQ
10-band dynamic EQ adjustment (± 12dB), built-in 8 preset EQ, support custom EQ
Navigation control
Gesture control/2-Bottom navigation/3-Bottom navigation
Power Parameters
power supply
Support QC3.0, QC4.0 and PD2.0 and PD3.0 quick charge
charging time
About 3.5 hours (QC3.0 quick charge mode)
Standby Time
>1000h
3.5mm headphone output: 10.5 hours
Volume
40
Screen status
Off
EQ
Off
Gain
super high
Tracks formats
MP3 44.1kHz/16bit
Load
32 Ω
FAQ:
1. M15S Complete user manual, firmware download, etc.
M15S Complete user manual: Click here
FiiO USB DAC driver download: Click here
Firmware download Link:Click here
2. What should I do if the M15S crashes or freezes?
Follow the measures below to see if it can help if the M15S crashes or freezes:
1.【Force to reboot】
Please hold the power button for around 10 seconds until the ""FiiO"" logo shows up.
2.【Extract a LOG file】
For special software issues, please extract a LOG file under the root directory, unzip and copy it to the homepage. And then send it to us for analysis.
Please go to " Settings ->About device" , and continually tap “Model number", until the prompt "Have save output log to built-in storage" appears.
Then please wait for about 20 seconds, and go to M15S's internal storage, then send the folder "fiio_log " to us and inform us the time of the problem for further analysis.
3.【Fail to be charged or turned on】
a. Hold the power button for about 10 seconds when it is charging
b.Try other power adapters and charging cables.
c.The battery of your device may be overused, so it needs to be refreshed through low-current power. It is suggested to charge it through the computer for more than 2 hours, and then unplug the charging cable to see whether it can be turned on.
d. If the problem still exists, please try to leave the device aside for 2 to 3 days, and then charge it again. Because sometimes its system may be stuck, it would return to normal when the device runs out of power.
If the above measures can not help, please ask the local seller for help or contact us by sending an email to support@fiio.com.
4. What can be done if I forget my password?
The device needs to be reset to factory data mode if you forget the password.
Turn off the device first. Hold the pause/play button and plug a USB cable in for power supply. It will enter recovery mode after turning on. On the display, choose "Wipe data/factory reset->Yes until it finishes. Then choose "Reboot system now" to start the device.
Notes:
1. Choose menu: use the volume buttons or previous track buttons
2. Confirm: short press the power button
3. What accessories are included in the M15S?
Other than the M15S, it also has the following accessories:
Leather case
USB cable
Quick start guide
Warranty card
Ejector pin
[Sigal input supported by M15S]
M15S supports USB input, Bluetooth receiving, AirPlay to meet your multiple use conditions.
[Output supported by M15S]
M15S supports 2.5mm/4.4mm balanced,3.5mm headphone out and Bluetooth out, USB Audio out.
4. How to enter enhanced over-ear headphone mode(Ultra High mode) and Desktop mode?
When the M15S is connected to fast charging adapter, the enhanced over-ear headphone mode could be enabled. At this time, the system will pop up a window to prompt the selection of Ultra High Mode and Desktop mode. And the enhanced over-ear headphones mode will be added to the gain setting menu. Please choose whether to switch according to your needs.
Ultra High Mode
The max output power will be1200mW@32Ω in the ultra high mode, and the power supply of
the amp module will be increased to +7.6V.
Desktop mode
When the desktop mode is selected, the machine will be powered by USB, and its battery will neither be charged nor powered, effectively increasing battery life.
How to exit Desktop mode?
You could turn off the Desktop mode from system setting-General-Desktop mode.
5. How to access the storage/SD card after connecting the M15S to a computer?
For Windows computers, it is driver-free. After connecting the M15S to the computer by the included USB cable, the driver will be automatically installed. Then the FiiO M15S disk can be directly seen on the computer.
Mac computers need a driver.
1.After connecting the M15S to the Mac computer, click the ""NO NAME"" folder emerging on the desktop->double click Mac->Mac/MAC OS MTP Client->Android File Transfer.dmg. Drag the ""Android File Transfer.dmg"" to the desktop of the computer.
2. Drag the ""Android File Transfer"" file to the ""Applications"" folder and wait for the completion of the copy.
3. Enter ""Applications"", and double click the ""Android File Transfer"". Then you can manage the files stored in the internal storage of the M15S or the Micro SD card.
Notes: The M15S folder will directly pop up the next time it is being connected to the same computer.
6. How to upgrade the M15S?
The M15S supports online upgrade and local upgrade.
1.Online upgrade
If a new firmware is available and can be detected (with the M15S connected to an available internet), an upgrade notification will show up in the notification center. Tap on it to enter the update menu for the online upgrade. If there's no upgrade notification showing up, you can go to the ""Technical Support->Firmware Upgrade"" menu, and tap the ""Check for updates"" icon to check manually.
2.Local upgrade
Also, the M15S can be upgraded locally by a firmware package. Download the firmware package file from FiiO website, and copy it to the internal storage of the M15S or an SD card. Go to the ""Technical Support->Firmware Upgrade->Local Upgrade"" menu, and find the firmware package file to start the upgrade.
Notes:
1.Do not unzip the firmware package file.
2.Before the upgrade, ensure the power of the device is adequate (>30%) so to avoid upgrade failure.
3.If the device goes to factory mode which cannot detect the firmware, the reason may be that the firmware file is damaged. At this time, press the power button to reboot the device. Re-download the firmware file and restart the upgrade.
7. How to install third-party applications?
There are two ways to install applications that are similar to mobile phones'.
1.After connecting the device to a valid WiFi, go to FiiO market, Google Play or other app markets to download and install the app directly.
2.Local installation: copy the APK file to the M15S. Go to the file management menu to find the file and install it.
8. How to switch the working mode of the M15S?
The M15S has 5 independent working modes: Android mode, Pure Music mode, Bluetooth Receiving mode, USB DAC mode and AirPlay mode. It is defaulted to be the Android mode, which can be switched to other working modes in the drop-down menu.
If the player is in other modes but not the Android mode, you can switch it to other modes through the selection on the display, or tap Settings->Exit to go back to Android mode.
9. How to enable the USB DAC function?
For Mac computers, it is driver-free.
For Windows computers, please make the settings as the followed steps.
1.Install the FiiO DAC driver in the computer first.
2.Switch the working mode of the M15S to USB DAC mode on the drop-down menu or go to Settings->Mode choose menu to enter the USB DAC mode.
3. Connect the M15S to the computer by the USB port. Select the M15S as the audio input both in the computer and the music app, so it can work.
Notes:
When in the USB DAC mode, the M15S does not support Bluetooth transmitting.
10. How to use the M15S as a Bluetooth receiver?
1. Go to the drop-down or Settings menu of the M15S, and choose the working mode as Bluetooth receiving mode.The M15S will enter pairing state automatically at the first time.
2. Go to the Bluetooth transmitting list of the mobile phone, and tap the M15S to complete the connection.
Note:
1. You could hold the play/pause button for 5 seconds to re-enters pairing state in the M15S.
2. The M15S will reconnect the Bluetooth device connected previously after enter Bluetooth receiving mode again.
11. How to use the M15S as a Bluetooth transmitter?
1. Go to the Settings->Bluetooth menu to turn on the Bluetooth function.
2.Make the Bluetooth receiving device, such as Bluetooth earphones, enter the pairing state. (Please refer to the user manual of the Bluetooth receiving device about how to enter pairing state.)
3.Go to the Bluetooth device list of the M15S->Pair new device to complete the connection.
What can be done if the M15S fails to connect to Bluetooth earphones?
If it fails to connect to Bluetooth earphones for the first time, please make sure the earphones are under pairing state (the connection will fail if the earphones are under reconnecting state for the first-time connection). Go to the Bluetooth menu of the M15S to start the connection.
What Bluetooth codecs does the M15S support? And how to switch the Bluetooth codecs?
The M15S supports LDAC, aptX-HD, aptX, AAC and SBC which can be switched on Settings->Audio->Wireless playback quality menu.
What can be done if the volume is too low when the M15S is connected to AirPods?
Go to Settings->About phone, and continuously tap the ""Build number"" 7 times. Go back to Settings->System->Developer options menu to turn off the""Disable absolute volume"". Disconnect and reconnect the two devices through Bluetooth.
12. How to connect the M15S to an external decoder? Does it support USB audio digital output?
The M15S supports USB audio. The setting steps are as follows.
1. Enable ""USB output"" in FiiO Music app of the M15S.
2.Use an OTG cable to connect the M15S and the external decoder.
3.Open FiiO Music app or other music applications to use the M15S as a USB digital output device.
It supports most of the decoding devices on the market. For those unsupported, you can turn off the USB output in FiiO Music app, or unplug and re-plug the USB device after quitting the FiiO Music app. If it does not work, please contact us by sending an email to support@fiio.com for further help.
13. What is the function of the M15S' In-vehicle mode? And how to use it?
【Principle】After turning on the In-vehicle mode, you can connect the M15S to the on-board USB port, and the M15S will power on automatically and switch to the In-vehicle mode screen when the vehicle engine starts, and power off automatically when the vehicle engine stops.
【How to set】Go to Settings->Global->In-vehicle mode, or the drop-down menu to turn on the in-vehicle mode.
(Some onboard USB ports may encounter interruptions when connecting to the M15S, in which case you can try to use FiiO's USB isolator, the LA-UA1, to fix the problem.)
14. What power supply adapter is suggested to charge the M15S?
Fast charging protocols including QC2.0/3.0/4.0 and PD2.0/3.0 are supported. If the power adapter supports either the above protocol, it can trigger the fast charging function
If the power adapter does not support neither the above protocol, it will not trigger the fast charging function but just common charging.
For non-fast charging adapters, it is suggested to use the 5V 1A/2A power adapters.
15. How to use the FiiO Link Bluetooth function?
There are mainly 3 steps.
1. On the FiiO Music app of the M15S, Settings->FiiO Link->┆ (on the upper right corner of the display), choosing Bluetooth as the Server.
2.Connect the M15S to the mobile phone through Bluetooth.
3.On the FiiO Music app of the mobile phone, Settings->FiiO Link->┆ (on the upper right corner of the display), choosing Bluetooth as the Client.
Notes: iPhones only support FiiO Link WiFi function but not Bluetooth.
16. How to use the FiiO Link WiFi function?
There are mainly 3 steps.
1.Make sure the M15S and your mobile phone are connected to the same WiFi network.
2.On the FiiO Music app of the M15S, Settings->FiiO Link->┆ (on the upper right corner of the display), choosing WiFi as the Server. Now an IP address will show up.
3. On the FiiO Music app of the mobile phone, Settings->FiiO Link->┆ (on the upper right corner of the display), choosing WiFi as the Client. Input the IP address in the pop-up dialog and complete the connection.
Notes: iPhones only support FiiO Link WiFi function but not Bluetooth.
17. How to use the AirPlay function?
The AirPlay function will only be available when connecting the M15S to iOS devices but not Android devices. There are mainly 3 steps.
1. Make sure the M15S and your iOS devices are connected to the same WiFi network.
2.Switch the M15S to the AirPlay mode.
3.On the drop-down menu of the iOS device, choose the M15S as the playing device. So the M15S can receive audio signals from the iOS device.
18. How to use the DLNA function?
The DLNA function means the M15S can read and receive music files stored on the device (name it Device A) which supports DLNA function through WiFi.
1. Make sure the M15S and Device A are connected to the same WiFi network.
2.On the FiiO Music app of the M15S, tap DLNA on the main menu and search for Device A to play music of it.
Notes: If there are any devices that cannot use the DLNA function, please give us feedback for further analysis. FiiO Music app does not support music transmission at present but only music reception. We will consider adding the transmission function later.
19. Instructions for Settings->Audio menu
3.5Output selection
PO (Power output), generally used when connecting to earphones and speakers
LO (Line out), generally used when connecting to power amplifiers
SPDIF (Coaxial out), generally used when connecting to DACs
2.4.4Output selection
BAL.PO and BAL.LO available
3.SPDIF out (it only needs to be set in this way when the coaxial output is used)
D2P mode: when playing PCM signals, it will output raw PCM signals; when playing DSD signals, it will first convert DSD to PCM and output PCM signals.
DoP mode: PCM will be output as PCM signals while DSD will be output as raw DSD signals.
Notes:
Select DoP first. For some devices that are not supportive of DoP, please select D2P.
4.Gain
There are 4 levels, Over-ear headphone mode, High, Medium and Low, corresponding to 4 levels of output voltages. You can select different Gains according to the earphones used.
When the M15S is connected to fast charging adapter, the enhanced over-ear headphone mode could be enabled.
5.Lowpass filters mode
There are 7 different filters built in the M15S for your preference.
Filters are the sound effects born with the chip, which only has slight adjustments for the sound. Here are some introductions to some filters. These are only for reference since actual listening also has something to do with the matched device.
1) fast roll-off,linear phase filter: Most Common filter with clean suppression and high rejection, best for music with high transients. Provides crisp clean highs
2) slow roll-off,linear phase filter: coherent and clear sounds, positioned near the middle. It is suitable for classical music.
3) fast roll-off, minimum phase filter: Minimal Pre- Ringing, preferred for Imaging and soundstage. No aliasing in frequency domain. Stronger bass than Linear Phase,clean highs
4) slow roll-off, minimum phase filter: Non-Symetrical filter designed to minimize pre-ringing. Strong punchy bass with good transient attacks
6.Bluetooth Audio Encoder
The Bluetooth transmission takes the highest codec by default. You can choose the highest codec supported for the Bluetooth connection by this option.
7.Balance
If there is any imbalance between the left and right channels when playing music, you can adjust the channel balance here. It has up to 10 levels available.
8.All To DSD
When the All To DSD function is turned on, the PCM signals will be converted to DSD for output with sound quality further improved.
【Principle】All To DSD is mainly about switching digital signals from PCM to DSD format. So when making digital-to-analog conversion, it can use DSD format, enriching music styles with clearer and natural sound quality. In addition, since the lowest format of the DSD is DSD64, i.e. 4 times of the 44.1k/16bit (just looking at the data size), the All To DSD function is upsampling the 44.1k/16bit audio signals. Third-party apps also support All To DSD.
【Notes】 When the All To DSD function is turned on, the CPU will consume more power, which will shorten the play time of the M15S with obvious heating on the body.
During the process of using, if you notice that the total battery life is much shorter than that written on the specification table on our website, please check if the All To DSD function is turning on. It is suggested to turn off the All To DSD function and follow the provided test conditions to check the battery life of the M15S again.
9.Adjustable volume at LO
When it is turned on, the volume will be adjustable in LO mode. If it is turned off, the volume will be fixed as maximum.
20. The indication of sampling rates
On Settings->Display->Sample rate display menu, turn on this option, so it can display the sampling rate of the playing music file.
21. The settings of indicator lights
On the Settings->Display->Indicator light control menu, you can make settings for the brightness of the volume knob indicator light, and display states when the M15S is working or charging. You can also set different display modes for the color light.
22. How to set the system with maximum volume or self-define power-on volume?
Relevant settings can be done on the Settings->Global->Volume setting menu.
1.System Maximum volume setting
2.Touchbar Maximum volume setting
3.Fixed volume setting (to customize the preset volume each time turning on the device)
23. How to change the language on the M15S?
1.Go to Settings->System->Languages and input->Languages->Add a language to choose the intended language.
2.Press the ""="" icon on the right side and drag it to the first line to select the language successfully.
Notes: The language of the FiiO Music app defaults to follow the system's. You can also go to FiiO Music app-> Settings->Languages to choose the language independently.
24. What can be done if the volume is too low when the M15S is connected to AirPods?
1.Go to Settings->About phone, and continuously tap the ""Build number"" 7 times to activate the Developer mode.
2.Go back to Settings->System->Developer options menu to turn off the""Disable absolute volume"".
3.Disconnect and reconnect the Bluetooth.
25. How to optimize the system if it runs slow and unsmooth?
The system runs slow: go to Settings->Storage menu to clean the system and free up space.
Errors happen to FiiO Music: go to Settings->Apps and notifications->All apps->FiiO Music->Storage&cache menu to clear the app.
26. Lyrics display, screenshot and system navigation way of the M15S
【Lyrics display】
Yes. Name the LRC lyrics file the same as the music file and put them in the same folder. On the music playing page, tap the cover on the middle of the screen to switch to the lyrics display page.
【Screenshot】
Use 3 fingers to swipe down the screen. Or hold the power button and volume- button together to get a screenshot.
Where does the screenshot store: FiiO M15S\Files\Internal storage\Pictures\Screenshots
【System navigation way】
The M15S is controlled by gesture navigation by default. It can be changed to 2-button or 3-button navigation way on the Settings->Global->System navigation menu.
DUAL CS 518 Manual V4 JP
No, there is no screen protector applied in the display of the M15S before factory out.
28. When connecting the M15S to the Windows computer, the drive letter shows M17/R7?
If you have connected the M17/R7 to the same Windows computer before connecting the M15S, you will meet this problem. Please go to the device manager and right click the M17/R7, then select uninstall option. Reconnect the M15S and the drive letter will show M15S now.