FiiO K3 Complete User Manual

1. Product Introduction

The FiiO K3 is a multi-function USB DAC (Digital-to-Analog Converter) designed for PC-HiFi systems. When connected to a computer, it can perform functions such as USB decoding, act as a USB digital interface, and handle audio decoding and amplification.

Product Features:

• Dual USB AUDIO mode
• Flagship decoding capability: PCM384k/DSD256
• RGB work indicator
• Dual headphone outputs, dual digital audio outputs
• ADC type volume control

List of Items Included in Package:

(Please check to make sure that all items are included)

1. USB A-Type C cable (1 pc)
2. Spare foot pad (4 pcs)
3. Quick user guide (1 pc)
4. Warranty card (1 pc)

Note: The products, accessories, user interface, and other illustrations in this manual are schematic and for reference only. Due to product updates and upgrades, the actual product and schematic diagram may be slightly different. Please refer to the actual product.

2. Ports and Indicators Explained

The FiiO K3 features a variety of ports and indicators:

Device Layout:

[Diagram Description: Top view of the FiiO K3 showing controls like BAL, GAIN, BASS, volume knob, and RGB indicator. Rear view showing LINE OUT, USB AUDIO switch (1.0/2.0), COAX OUT, and OPT OUT ports.]

Port and Indicator Descriptions:

1. 2.5mm Balanced Headphone Output Interface: Connect a 2.5mm earphone to this jack. The balance boost function will be activated automatically, potentially improving output power by about 50%.
2. 3.5mm Single-Ended Headphone Output Interface: Connect a 3.5mm headset to this jack.
3. Bass Boost Switch: When the switch is turned to the left, bass boost is OFF; when switched to the right, bass boost is ON.
4. Low/High Gain Switch: When the switch is turned to the left, it indicates low gain. When switched to the right, it indicates high gain. The high gain setting can be adjusted based on different types of headphones.
5. RGB Indicator: This light is located next to the power/volume knob. While playing music, the indicator displays different colors according to the sampling rate.
6. Power/Volume Knob: Turn the knob clockwise to stop and turn the power on. Continue rotating clockwise to increase the volume. Turn counterclockwise to decrease the volume. Continue rotating counterclockwise until you hear a beep to turn off the power. When the power is off, the white dot on the knob points towards the RGB light.
7. Linear Output: Directly driven by OPA1612, ensuring high-quality sound reproduction. Suitable for speakers, amplifiers, decoders, etc.
8. USB Mode Selection Switch: When the switch is set to 1.0, it is USB Audio 1.0 drive-free mode. When dialed to 2.0, it represents USB Audio 2.0 drive mode.
9. Type C USB Interface: Connect the computer (Windows or OS system) to power the K3. This port is also used for audio input.
10. COAX OUT (Coaxial Output): This digital output port is used to connect speakers, amplifiers, or decoders with coaxial input.
11. OPT OUT (Optical Output): This optical output port is for connecting speakers, amplifiers, or decoders with optical input.

3. Usage Steps

Step 1: Select the appropriate USB mode and connect to the computer with the data cable.

[Diagram Description: Illustration showing the FiiO K3 connected via USB Type-C cable to a laptop. The USB AUDIO switch on the K3 is shown.]

• USB Audio 1.0: Decoding sampling rate can reach 96k/24bit, no driver needed. After connecting the data cable, turn the power/volume knob clockwise until you hear a click and the device turns on. Select the K3 device on the computer.
• USB Audio 2.0: Decoding sampling rate can reach 384k/DSD256, requires driver installation on Windows. After connecting the data cable, turn the power/volume knob clockwise until you hear a click and turn the device on. For MAC computers, no driver installation is needed, but K3 must be selected as the sound device in Mac settings.

For Windows system computers, please visit the FiiO official website to download and install the USB driver. Download link: www.fiio.com/q1mkiifaq. For driver installation tutorials, please see Appendix 1 of this document. Select K3 as the output device on the computer.

How to select K3 as sound device:

For example, on a Windows 7 system, right-click the desktop taskbar volume icon, select the playback device to enter the "sound" management interface, and finally choose "FiiO Q-series" speaker as the default.

Note:

• The USB mode (1.0 to 2.0) switch requires re-plugging and connecting to the computer.
• Because the K3 needs power from the source, and power supply and data transfer share the same slot, it is designed for desktop computers or notebooks. Mobile devices are not recommended.
• When the phone is turned on or plugged in, the indicator light will flash then remain ON.
• When the K3 is turned off or disconnected, the indicator light will be off.

Step 2: Select output jack according to the usage scene.

Scene 1: Connect to the headset using a 2.5mm or 3.5mm port.

[Diagram Description: Illustration showing the K3 with 2.5mm and 3.5mm headphone jacks, and a pair of headphones connected to one of them.]

Note:

• When both the headphone jack and the BAL jack are plugged in, only the BAL jack will be valid.
• If you want to use the 3.5mm headphone jack, please unplug the 2.5mm balanced jack device.

Scene 2: Connect to an active speaker or amplifier with a 3.5mm audio cable.

[Diagram Description: Illustration showing the K3's LINE OUT port connected via a 3.5mm audio cable to two active speakers.]

Note: The line out is controlled by the power/volume knob and can work with 2.5mm/3.5mm output simultaneously. However, it is recommended to eject headphones while using the line out.

Scene 3: Connect to the amplifier with coaxial input.

[Diagram Description: Illustration showing the K3's COAX OUT port connected via a coaxial cable to an amplifier's coaxial input.]

Note: The coaxial output supports up to 192k sampling rate and DOP output of DSD64. If the connected device does not support this, please adjust the audio output settings of the PC player. Power/volume knob adjustment is invalid to the coaxial output volume.

Scene 4: Connect to the device with optical input port.

[Diagram Description: Illustration showing the K3's OPT OUT port connected via an optical cable to a device's optical input.]

Note: The optical output supports up to 96k sampling rate. If the connected device does not support this, please adjust the audio output settings of the PC player. Power/volume knob adjustment is invalid to the optical output volume.

Step 3: Play the song on the computer using the music app.

First, select K3 as the output device in the playback settings of your music software. For example, using FB2000 (see Appendix 2 for reference). Then, play the music and adjust the power/volume knob to the appropriate volume to enjoy the music.

Note:

• It is recommended to adjust the volume of the computer to the maximum. Control the output volume of the unit by adjusting the volume knob.
• When playing songs with different sampling rates, the indicator light will change to display a specific color accordingly:
  • Playing music with a 48KHz sample rate or below will display blue.
  • Playing music with a sample rate above 48KHz will display yellow.
  • When playing a DSD track, it will display green.
• Bass: With the bass boost function switch on, there will be a strong bass effect when playing music.
• Gain: The maximum output with high gain is 6dB higher than the low gain, which is suitable for higher impedance headphones. Please change the gain switch according to the following steps safely: Turn off K3 first, then turn the gain switch to the high gain position, then turn on the unit and gradually adjust to appropriate volume.

Switching to high gain during use will increase the output power suddenly, which may damage your headphones and hurt your ears.

5. Safety Instructions

• ⭐ When the system is abnormal, try re-plugging the USB cable.
• ⭐ Before using, please adjust to an appropriate volume (the LINE OUT volume can also be adjusted).
• ⭐ To avoid pop sound that can hurt your ears, it is not recommended to wear headphones before plugging them in.
• ⭐ Do not repair by yourself, disassemble, or place the product in a location with water.
• ⭐ When using headphones, you will not be able to hear the external environment. For your personal safety, please use headphones in a safe environment, not a dangerous one.
• ⭐ Switching to high gain during use will increase the output power suddenly, which may damage your headphones and hurt your ears.

6. Troubleshooting

The following are some of the problems that may occur during use and their solutions. If you encounter an unsolvable problem, please contact FiiO customer service center at support@fiio.com.

Fault 1: No sound output

• Check whether this unit is turned on.
• Check whether the latest driver is downloaded from the official website and installed correctly.
• Check whether Control Panel > All Control Panel Items > Sound shows "FiiO Q series".
• Check whether "FiiO Q series" is the default device in "playback device" settings.
• Check whether the headset is plugged in completely.
• Check whether the volume is too low; increase the volume of the connected device or adjust the volume knob of K3 to increase the unit's volume.

Fault 2: Small sound

• When using a high-impedance earphone, it is recommended to set the GAIN switch to "H".
• You can increase the volume of the connected device or adjust the volume knob of K3 to increase the volume of the unit.
• In-ear earphones and headphones are recommended for PO or BAL output. Insertion of line output may result in less sound.

7. Specification List

Note: Specifications are subject to change without notice.

8. Learn More

To learn more about FiiO products, please go to http://www.fiio.com.

Appendix 1: How to Install Driver

Note: Please install the driver for K3 as follows (using Windows 7 32-bit system as an example).

First, visit the driver download link to download the official latest driver, as shown below:

[Image Description: Screenshot of a web browser showing the FiiO website with a section for driver download. A button labeled "Download" is visible next to "USB DAC Driver (v4.47.0)".]

After the download is complete, unzip the file and then double-click "FiiO_USB_DAC_Driver-V4.47.0.exe" to start the application installer.

After running the program, follow the steps below:

[Image Description: Screenshot of the driver setup wizard showing a "Confirm uninstallation" prompt for "FiiO Portable High-Res Music Player series v4.47.0".]

You can customize which disk to install on, or you can install it on the C drive as default. If installing on the default C drive, click "Install".

[Image Description: Screenshot of the driver setup wizard showing the "Choose Install Location" screen, with a destination folder path C:\Program Files\FiiO\FiiO_Driver.]

[Image Description: Screenshot of the driver setup wizard showing the "Installing" progress bar, with text indicating preparation and waiting.]

During the installation process, you may encounter 2-3 anti-virus software interceptions. You need to manually select "Allow this operation" or "Allow all operations of the program". "Allow loading" is very important; blocking the operation or loading will lead to failed driver installation.

[Image Description: Screenshot of the driver setup wizard showing "Installation Complete" with a "Next" button.]

[Image Description: Screenshot of the driver setup wizard showing "Completing the FiiO Portable High-Res Music Player series v4.47.0 Setup Wizard" with a "Finish" button.]

Appendix 2: FB2000 Choose K3 Operation Tutorial

Open FB2000, select the menu "Library - Configuration" to enter the parameter option setting interface, as shown below:

[Image Description: Screenshot of the foobar2000 audio player software, showing the menu bar with "Library" selected, and a dropdown menu with "Configuration" highlighted.]

The "Play" - "Output" device can be selected. For example, select "KS: K3", click "Apply", and then click "Confirm", as shown below:

[Image Description: Screenshot of the foobar2000 Preferences window, specifically the "Output" section, showing "KS: K3" selected as the Device.]

After selecting the output device, return to the main interface, select and play a song. Adjust it to the appropriate volume, plug in your headphone, and enjoy the music.

To play DSD songs, you can choose the following output:

[Image Description: Screenshot of the foobar2000 Preferences window, showing various output device options, including ASIO and WASAPI, with specific entries related to FiiO and DSD.]