Introducing the Fosi Audio Decoder DAC-Q4

Get ready to experience high-quality sound like never before with the Fosi Audio Audio Decoder DAC-Q4. This advanced decoder offers a wide range of features that make it an excellent choice for anyone looking to enhance their audio setup. With a sleek and compact design, this DAC is perfect for use at home, in the studio, or on the go. The estimated price for the Fosi Audio Audio Decoder DAC-Q4 is around $79.99, making it an affordable choice for anyone looking to upgrade their audio experience.

Package Contents

• Fosi Audio DAC-Q4 ×1

• 5V USB Power Supply Cable ×1

• PC-USB Cable ×1

• Optical Cable ×1

• User’s Manual ×1

Fosi Audio Decoder DAC-Q4 Specifications

The Q4 is a compact mini digital/analogue audio converter adapter with USB, optical and coaxial digital inputs, a classic 3.5mm headphone jack and RCA outputs, suitable for most home audio systems. With bass and treble controls, it can be used as a preamplifier or volume control for PC/MAC/Computer. Fosi Audio Q4 ensures exquisite musicality, accurate and realistic phasing, and reproduction of the original sound!

Product Overview & Control Functions

Description of Fosi Audio Decoder DAC-Q4

The Fosi Audio Decoder DAC-Q4 is a high-resolution audio decoder that supports PCM up to 32bit/384kHz and DSD up to 12.3MHz. It features a low noise floor, thanks to its high-quality components and circuit design. The DAC-Q4 is compatible with a wide range of devices, including computers, smartphones, and portable music players. It also features multiple input options, including USB, coaxial, and optical, making it a versatile choice for any audio setup.

Setup Guide

Setting up the Fosi Audio Decoder DAC-Q4 is easy. Simply connect it to your device using the USB, coaxial, or optical input. Then, connect your speakers or headphones to the DAC-Q4's audio output. The DAC-Q4 features a convenient volume control knob, making it easy to adjust the volume to your desired level. You can also switch between input sources using the input select button.

Fosi Audio Decoder DAC-Q4 Quick Setup 

PC-Windows for example

Q4, PC, AC adapter, PC-USB cable, Micro-USB cable, Headphones.

• Connect the Micro-USB cable to the AC adapter, then connect the Micro-USB cable to the Q4;

• Connect the Q4 to the PC via the PC-USB cable;

• Turn down the volume control to lowest level(turn off the power switch)and connect the headphones to the 3.5mm headphone jack;

• Adjust input mode selection key to select USB input mode;

• Turn on the power switch (turn up the volume); (Note: The power switch is also the volume control knob. Turn on: Turn the volume knob clockwise to the right; Turn off: Turn the volume knob counterclockwise to the left and adjust the volume to minimum.)

• Left click on the computer desktop sound icon and select Device: “Fosi Audio Q4″(Digital HiFi Audio);

• Open the audio application, play and enjoy!

NOTE: Before connecting the power supply, please turn down the volume control to the lowest level, to avoid your hearing from damage.)

PC-Windows for example

Optical for example

Q4, AC adapter, Micro-USB cable, optical device (TV for example), optical cable.

1. Connect the Micro-USB cable to the AC adapter, then connect the Micro-USB cable to the Q4;

2. Connect the TV to Q4’s optical interface via the optical cable;

3. Adjust the input selection button to select optical mode; Step 4: Set the TV’s optical output sound to RAW/PCM;
   NOTE: Due to different TV types, some TVs default Dolby or DTS sound output, Q4 DOES NOT Support Dolby and DTS sound, please select RAW/PCM Sound, otherwise you will hear a lot of noise or no sound output.) 

4. Open the audio application, play and enjoy!

   

Coaxial for example

1. Q4, AC adapter, Micro-USB cable, Coaxial device (TV for example), Coaxial cable (no include).

2. Connect the Micro-USB cable to the AC adapter, then connect the Micro-USB cable to the Q4;

3. Connect the TV to Q4’s coaxial interface via the coaxial cable;

4. Adjust the input selection button to select coaxial mode;

5. Set the TV’s coaxial output sound to RAW/PCM;
   NOTE: Due to different TV types, some TVs default Dolby or DTS sound output, Q4 DOES NOT support Dolby and DTS sound, please select RAW/PCM sound, otherwise you will hear a lot of noise or no sound output.) 

6. Open the audio application, play and enjoy!

   

Troubleshooting

1. How do I power the DAC-Q4?
   You will need to use the supplied Micro-USB cable to power it, we recommend using the PC-USB port/5V power adapter to power  it.
   Note: The Micro-USB cable cannot be fully inserted into the device power port, please do not force it. Subsequent revisions have been made.

2. Why is it that all my wires are plugged in, but the Q4 RCA analog output is silent?
   At this point, you should check to see if the headphone output is plugged into the headphone. If so, you should unplug the headset to simulate RCA output.

3. Why do I get endless white noise?
   Please check that your input device is using Dolby/DTS audio, please switch off Dolby/DTS audio and try again.

4. No Dolby/DTS audio and I still get noise through the USB input?
   Please switch the USB port to USB 3.0 or back USB port and try again, as some USB ports have unstable data transmission;
   Please try again with another computer;
   Please replace the PC-USB cable and retest, contact us for compensation if the original cable is faulty;
   Please change the power supply adaptation and retest, why?
   Because of the ageing of the power supply there may be an abnormal power supply resulting in white noise. We recommend using the PC-USB port/5V power adapter to power it.

5. USB Device not recognized on Windows?
   Select Start, then type device manager in the Search box, and then select Device Manager;
   Expand Universal Serial Bus controllers. Press and hold (or right-click) a device and select Uninstall. Repeat for each device;
   Once complete, restart your computer. Your USB controllers will automatically install. If Windows update causes the device to be unrecognized, please update all windows components and reboot, retest. Please contact me for a solution.

6. How to do plug and play on Windows?
   Just click the sound icon in your notification area;
   Click the “Select playback device” option;
   Select the playback device “Fosi Audio Q4”(Digital HiFi Audio).

7. I can’t play Spotify music in Plug and Play mode?
   Please exit the Spotify app and switch the playback device to the computer’s own sound card device, open Spotify and play, confirm that it works and then switch the playback device to DAC-Q4 “Digital HiFi Audio”

8. How do I get the highest 24Bit/96kHz resolution on my PC?
   Right-click the PC sound icon in the lower right corner, open Volume Mixer, click on the icon of the device/SPDIF: “Digital HiFi Audio” to open the Properties, click the Advanced, select 24Bit, 96000Hz for maximum sound quality output.

9. Why do I get an intermittent sound?
   Please switch the USB port to USB 3.0 or back USB port and try again, as some USB ports have unstable data transmission;
   Please replace the PC-USB cable and retest, contact me for compensation if the original cable is faulty.

10. Why there is no sound when PC-USB connects to PC?
    First press the PC-USB operation to confirm whether the digital playback output has been selected. If still no sound, you can restart the computer and repeat the operation again, also please make sure you had select correct device name on your PC sound setting.
    Some computers’ USB port are low quality on the front panel, please change USB port to have a try, it’s better use the USB port on the back panel of the computer.

11. Why my device stopping working after short time use?
    Make sure your audio source and the headphones, amplifier or powered speakers you connected are works well. And please check all the connection of the input and output cables, please change the audio source, output devices, cables to try again. Also please check the power supply works or not.

Comparison Section

Model	Q4	N2	K1	K2
Picture
Bluetooth Version	–	–	5.0	5.0
Headphone Output Impedance	16-200 (Ω)	16-200 (Ω)	16-200 (Ω)	16-200 (Ω)
Input Ways	USB+OPT+COA	16-200 (Ω)	16-200 (Ω)	16-200 (Ω)
Input Ways	USB+OPT+COA	AUX	BT+USB+ OPT+COA	BT+USB+ OPT+COA
Output Ways	3.5mm Headphone + RCA	AUX	3.5mm Headphone + RCA	3.5mm Headphone + RCA
Size	73.5*98*33mm	106*67*14mm	94*71*23mm	110*100*30mm

Fosi Audio Warranty information

All Fosi Audio products have an 18-month limited warranty on parts and labor from the date of purchase. Please contact us if you have any problems.

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!

Pros & Cons

Pros

• High-resolution audio decoding up to 32bit/384kHz and DSD up to 12.3MHz
• Low noise floor for clear and detailed sound
• Compatible with a wide range of devices and input options
• Sleek and compact design
• Affordable price point

Cons

• May not be compatible with some older devices
• Does not support wireless connectivity options

Customer Reviews about Fosi Audio Decoder DAC-Q4

Customers love the Fosi Audio Decoder DAC-Q4 for its high-quality sound and affordability. Many have noted that it offers excellent value for the price, with clear and detailed sound that rivals more expensive DACs. Some have noted that the build quality could be improved, but overall, customers are very satisfied with their purchase.

The most common complaints about the Fosi Audio Audio Decoder DAC-Q4 are related to compatibility issues with some older devices. Some users have reported that they were unable to get the DAC to work with their older computer or audio player. However, compatibility issues can often be resolved by updating the device's software or drivers.