DAC-Q4 - Earphones Fosi Audio - Free user manual and instructions

Product Type	USB DAC and Headphone Amplifier
Model	DAC-Q4
Brand	Fosi Audio
Dimensions (W x H x D)	10 cm x 3 cm x 8 cm
Weight	200 g
Power Supply	USB 5V/500mA
Input Interface	USB Type-B, Optical (Toslink)
Output Interface	3.5 mm headphone, 6.35 mm headphone, RCA line out
Max Sampling Rate	Up to 24-bit / 192 kHz
Supported Formats	PCM, FLAC, WAV, APE, WMA
Headphone Impedance	16-300 ohms
Signal-to-Noise Ratio	>110 dB
Total Harmonic Distortion	<0.005%
Volume Control	Analog potentiometer
Operating System Compatibility	Windows, Mac OS, Linux
Driver Required	Windows driver for ASIO; plug-and-play on Mac/Linux
Power Indicator	Blue LED
Chassis Material	Aluminum alloy
Maintenance Instructions	Clean with a dry, soft cloth. Do not use liquid cleaners.
Safety Warnings	Do not expose to moisture or extreme temperatures. Use only supplied USB cable.
Spare Parts & Repairability	No user-serviceable parts. Contact support for repairs.
Package Contents	DAC-Q4, USB cable, optical cable, user manual
Warranty	2 years

Frequently Asked Questions - DAC-Q4 Fosi Audio

How do I connect the DAC-Q4 to my computer?

Use the included USB cable to connect the DAC-Q4 to a USB port on your computer. The device is plug-and-play on most systems. For Windows, you may need to install the driver from the Fosi Audio website for optimal ASIO support.

Does the DAC-Q4 support optical input?

Yes, it has an optical (Toslink) input for connecting devices like gaming consoles or TVs.

Can I use the DAC-Q4 with headphones that have high impedance?

The DAC-Q4 works well with headphones from 16 to 300 ohms. For very high impedance headphones, consider an external amplifier.

How do I switch between headphone and line output?

The headphone output and line output are independent. Simply plug into the appropriate jack. The headphone output mutes when nothing is connected.

Why is there no sound from my headphones?

Check the volume knob is turned up. Ensure the USB power is connected and the input source is selected. Also verify the audio output settings on your device.

Does the DAC-Q4 require a driver for Mac?

No, it is plug-and-play on Mac OS. No additional driver is needed.

What is the maximum audio resolution supported?

The DAC-Q4 supports up to 24-bit / 192 kHz PCM audio.

How do I clean the DAC-Q4?

Use a dry, soft cloth to wipe the surface. Avoid using any liquids or abrasive cleaners that could damage the aluminum chassis.

Can I use the DAC-Q4 with my smartphone?

Yes, if your smartphone supports USB OTG, you can connect it via a USB OTG cable. Note that power might be limited; an external USB hub with power supply is recommended.

Is there a warranty for the DAC-Q4?

Fosi Audio provides a 2-year warranty against manufacturing defects. Keep the original receipt for warranty service.

USER MANUAL DAC-Q4 Fosi Audio

Fosi Audio

Fosi Audio DAC-Q4 User Manual

Product 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!

Input Type: USB, Optical, Coaxial
Output Type: 3.5mm Headphone, RCA
Chipset: SA9023+CS8412+	97220+NE5532
USB Sampling Rate: 24Bit/96kHz
Optical/Coaxial	24Bit/192kHz
Sampling Rate:
Headphone Impedance: 16-200Ω
RCA Output Level: 2.3V
Power Supply: 5V
THD: ≤0.01%
SNR: ≥105dB
Size (L*W*H): 73.5*98*33MM
Net Weight: 0.4kg

Product Overview & Control Functions

Package Contents

Fosi Audio DAC-Q4 ×1

5V USB Power Supply Cable ×1

PC-USB Cable ×1

Optical Cable ×1

User's Manual ×1

Quick Setup

PC-Windows for example

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

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

Step 2: Connect the Q4 to the PC via the PC-USB cable;

Step 3: Turn down the volume control to lowest level(turn off the power switch) and connect the headphones to the 3.5mm headphone jack;

Step 4: Adjust input mode selection key to select USB input mode;

Step 5: 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.)

Step 6: Left click on the computer desktop sound icon and select Device: "Fosi Audio Q4"(Digital HiFi Audio);

Step 7: 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

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

Step 1: Connect the Micro-USB cable to the AC adapter, then connect the Micro-USB cable to the Q4;
Step 2: Connect the TV to Q4's optical interface via the optical cable;
Step 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.)

Step 5: Open the audio application, play and enjoy!

Fosi Audio

Optical for example

Coaxial for example

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

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

Step 2: Connect the TV to Q4's coaxial interface via the coaxial cable;

Step 3: Adjust the input selection button to select coaxial mode;

Step 4: 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.)

Step 5: Open the audio application, play and enjoy!

Coaxial for example

Troubleshooting/QA

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 AUX BT+USB+			OPT+COA	BT+USB+OPT+COA
Output Ways 3.5mm	Headphone+RCA	AUX	3.5mmHeadphone+RCA	3.5mmHeadphone+RCA
Size 73.5*98*33mm		106*67*14mm	94*71*23mm 110*1	100*30mm

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!

Our website: www.fosiaudio.com

Amazon store: www.amazon.com/fosiaudio

Our Youtube channel: Fosi Audio

Our Facebook page: Fosi Audio

After-sale Service and Technical Support Email:

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Fosi Audio Product's User Manual