FiiO K9 Desktop Headphone Amplifier User Manual

Introduction

The FiiO K9 is a high-performance desktop headphone amplifier and DAC designed to deliver exceptional audio quality. It integrates advanced components and versatile connectivity options to enhance your listening experience. This manual provides detailed instructions for setting up, operating, and maintaining your FiiO K9.

Key Features

• High-performance ES9068AS*2 DAC: Features two ES9068AS DACs, one for each channel, ensuring high-fidelity audio conversion.
• THX AAA 788+ Amplifier: Equipped with a THX AAA 788+ amplifier, providing up to 780mW at 300Ω and 2000mW at 32Ω with low distortion.
• Isolated Digital and Analog Power Supply: Separate power supplies for digital and analog sections minimize interference for pure sound reproduction.
• QCC5124 Bluetooth Chip: Supports Bluetooth 5.1 with LDAC, aptX HD, aptX Adaptive, aptX, aptX LL, AAC, and SBC codecs for high-resolution wireless audio.
• Professional PEQ via FiiO Control App: Customize your sound with 7 preset music tuning styles accessible through the FiiO Control app.

Product Overview

The FiiO K9 features a robust desktop design with clearly labeled controls and input/output ports. Familiarize yourself with the device's layout before proceeding with setup.

Image: Front and rear panels of the FiiO K9 Desktop Headphone Amplifier, showing all controls and connection ports.

Image: Angled view of the FiiO K9, highlighting its compact desktop form factor and antenna.

Front Panel Controls:

• Volume Knob: Adjusts the output volume. Features an RGB indicator for status.
• Input Selector: Cycles through USB, Optical, Coaxial, Line, and Bluetooth inputs.
• Output Selector: Switches between Line Out (LO), Pre Out (PO), and Headphone Out (HP).
• Gain Switch: Selects low, medium, or high gain for headphone output.
• Headphone Outputs: 6.35mm single-ended, 4.4mm balanced, and 4-pin XLR balanced.

Rear Panel Connections:

• AC Power Input: Standard IEC AC cable socket with voltage selector (100-120V / 220-240V).
• USB Input: USB Type-B port for connecting to a computer.
• Digital Inputs: Optical and Coaxial.
• Analog Inputs: RCA Line In and 4.4mm Balanced In.
• Analog Outputs: RCA Line Out and XLR Balanced Out.
• Bluetooth Antenna: For wireless connectivity.

Setup

1. Unpacking: Carefully remove all components from the packaging. Ensure the following items are present: FiiO K9 unit, AC power cable, USB Type-A to Type-B cable, 6.35mm headphone adapter, rubber feet, and quick start guide.
2. Voltage Selection: Before connecting the power cable, verify that the voltage selector switch on the rear panel is set correctly for your region (100-120V or 220-240V).
3. Placement: Place the FiiO K9 on a stable, flat surface. Attach the included rubber feet to the bottom of the unit to prevent scratching and ensure stability. A vertical stand is also provided for vertical mounting if preferred.
4. Power Connection: Connect the AC power cable to the K9's rear panel and then to a power outlet.
5. Input Connection:
   • USB: Connect the USB Type-A to Type-B cable from your computer to the K9's USB input.
   • Optical/Coaxial: Connect your digital audio source (e.g., CD player, TV) to the corresponding Optical or Coaxial input.
   • Line In (RCA/4.4mm Balanced): Connect analog audio sources to the RCA or 4.4mm balanced inputs. Note that the balanced input takes priority over the unbalanced RCA inputs.
6. Output Connection:
   • Headphones: Plug your headphones into the desired front panel output (6.35mm, 4.4mm balanced, or 4-pin XLR balanced). Use the 6.35mm adapter if necessary.
   • Line Out (RCA/XLR): Connect the RCA or XLR balanced outputs to a power amplifier or active speakers if using the K9 as a preamplifier.

Operating Instructions

Power On/Off:

Press the power button on the rear panel to turn the unit on or off. The volume knob's RGB light will illuminate upon power-on.

Input Selection:

Use the "INPUT" button on the front panel to cycle through available input sources: USB, Optical, Coaxial, Line, and Bluetooth. The selected input will be indicated by an LED.

Output Selection:

Use the "OUTPUT" button on the front panel to select the desired output mode: LO (Line Out), PO (Pre Out), or HP (Headphone Out). The corresponding LED will light up.

Volume Control:

Rotate the large knob on the front panel to adjust the volume. Adjust gradually to avoid sudden loud sounds.

Gain Adjustment:

Use the "GAIN" switch on the front panel to select between Low (L), Medium (M), and High (H) gain settings. Choose a gain level appropriate for your headphones' impedance and sensitivity.

Bluetooth Pairing:

1. Select Bluetooth as the input source using the "INPUT" button.
2. On your mobile device, search for Bluetooth devices and select "FiiO K9".
3. Once paired, the Bluetooth indicator LED on the K9 will remain steady.

FiiO Control App:

Download the FiiO Control app from your device's app store. This app allows for advanced control and customization, including switching between 7 preset music tuning styles (Professional PEQ).

Specifications

Image: A detailed table listing the technical specifications of the FiiO K9 amplifier.

Maintenance

• Cleaning: Use a soft, dry cloth to clean the exterior of the FiiO K9. Avoid using liquid cleaners or solvents, as they may damage the finish or internal components.
• Ventilation: Ensure the unit has adequate ventilation. Do not block the ventilation slots on the sides or top of the device.
• Storage: When not in use for extended periods, store the K9 in a cool, dry place away from direct sunlight and extreme temperatures.
• Cable Management: Keep cables organized and free from kinks or excessive tension to prevent damage to the cables or ports.

Troubleshooting

Official Product Video

Warranty and Support

For warranty information and technical support, please refer to the documentation included with your product or visit the official FiiO website. Keep your proof of purchase for warranty claims.

Optional protection plans are available for purchase separately, offering extended coverage beyond the standard manufacturer's warranty. Please check with your retailer for details on available plans.