Foreword & Specifications

Operation Instruction
Warranty Information
About Fosi Audio


Thank you very much for purchasing the DS2 headphone amp.
Please read the instructions carefully before using the product.
If you have any problems or suggestions for the product, please feel free to contact us via email. We are always at your service.
Email address of our technical support team:support@fosiaudio.com.

DAC Chipset

Dual CS43131


Output Power

SE: 128mw(32Ω) BAL: 510mw(32Ω)





Frequency Response

20HZ-20KHZ +/-0.5dB



Up to 32bit/384kHz





Dynamic Range






Recommended Headphone Impedance

16~300Ω(SE); 16~300Ω(BAL)


Supported Devices

Mac\ Windows\ iOS\ Android

Audio Stream Format

Sampling Rate

Display Colour












Product Overview & Packing List

Operation Instruction

1.Please use the included USB Type-C cable to connectthe DS2 to your Android/iPhone/Windows/Mac device.Please note: Due to system and hardware differences,some Android phones or music players may have compatibility issues, and some phones require enabling OTG function to use the DS2 properly.

2.When connecting the DS2 to a device with a Lightning connector, please use a Lightning to Type-C OTG cable(not included in the package).

3.When playing music on your computer, select "FosiAudio DS2" as the computer's audio output device.

4.Some devices may not have volume control inexclusive USB audio access mode.

5.The DS2 doesn't have a built-in battery, so it draws power from the audio source device via the USB port. Actual power consumption depends on usage and the device system. The DS2 features two high-quality DAC chips, so it's normal for it to generate heat during use.


Q1.Regarding heat and power consumption:
1. The DS2 does not have a built-in battery, so it will consume power from the connected device during use. Please be mindful of your device's battery life whenconnecting the DS2 to a smartphone or other devices.
2. Although compact in size, the DS2 delivers a high output power. The operational temperature rise is approximately 15-25 ℃ depending on the output powerused during operation. lt is normal for the device to feel slightly warm during use.

Q2.About playing DsD audio files:
1. When playing DSD files on Android devices, it is recommended to use applications that support DSD filedecoding(such as "HiByMusic APP"), enable dedicated USB audio access mode, set the DSD output option to DoP, and turn on exclusive mode.

2. When playing DSD files on iOS devices, it's recommended to use decoding-supported applications(such as "HiByMusic APP") and set the DSD output optionto DoP. Switching tracks with different sample rates may result in a slight POP sound, which is a normal occurrence
3. For playing DSD files on a computer, it is advised to use software that supports DSD file decoding (such as"Foobar 2000 on Windows or Audirvana on Mac")and ensure the related applications are correctly installed.(Please visit the Fosi Audio official website to download the Foobar installation package.)


03.What should be noted when connectingto the 4.4mm headphone iack?
1. Please do not use any 3.5mm to 4.4mm adapters as this may result in no sound, stuttering etc.during use.
2. lt is recommended to use 4.4mm headphones directly.

Q4.Can the DS2 be used to answer calls while connected?
The DS2 does not support call-answering capabilities while connected. Should you receive a call on your mobile phone while using the DS2 device, you will need to converse directly via your phone's speaker and microphone. The connection status of the DS2 will not interfere with the normal operation of your phone's call functions.

05.Potential issues when DS2 is connectedvia USB to various devices :
These issues may arise due to the exclusive USB audicaccess and compatibility differences across devices.Known scenarios include:
1. On certain phones or devices using specific playback software, the DS2's volume control buttons may not affect the device's volume.In such cases, please adiust the volume directly through your device.

2. Power management settings on some phones may prevent apps from running in the background, causing your music playback to stop a few seconds after the device goes to sleep. You can modify the power management settings on your device to allow music apps to run in the background.
3. Operating other applications while the DS2 is inexclusive USB audio mode may result in delays or nosound issues. We recommend focusing solely on music playback when using exclusive mode, or exiting exclusive mode to avoid these problems.

Warranty Information​

Fosi Audio pledges to give a 24-month limited warranty and support from the date of purchase. If you encounter any problem when using our product, please contact our support team at support@fosiaudio.com.

About Fosi Audio​

Fosi Audio designs and builds innovative audio products with all your music in mind. Great sound, simple but elegant designs, high-quality materials, and truly useful features are what Fosi Audio is about. We sincerely hope you get as much enjoyment from our products as we’ve had to create them!


Our Website: www.fosiaudio.com 

Amazon Store: www.amazon.com/fosiaudio 

Facebook Page: Fosi Audio 

Youtube Channel: Fosi Audio 

Whatsapp: +86 13716612254 

After-Sales Service and Technical Support Email: support@fosiaudio.com


DS2 2024 foobar installation