FiiO K5 Pro Desktop DAC and Headphone Amplifier User Manual

1. Introduction

The FiiO K5 Pro is a high-performance desktop Digital-to-Analog Converter (DAC) and headphone amplifier designed to elevate your audio experience. It features advanced decoding capabilities and a robust amplification stage, making it suitable for a wide range of headphones and audio setups. This manual provides detailed instructions for setting up, operating, and maintaining your K5 Pro.

Figure 1: FiiO K5 Pro Desktop DAC and Headphone Amplifier

2. Product Features

• High-Performance DAC & USB Decoding: Equipped with an ES9038PRO DAC chip for 32-bit processing and an XUF208 USB decoding chip, supporting up to 768kHz and DSD512 inputs.
• Versatile Inputs: Supports Coaxial, Optical, and RCA line-in inputs. Optical and Coaxial inputs support up to 192kHz.
• Multiple Outputs: Features a 6.35mm (1/4 inch) headphone output and RCA line-out outputs. The RCA line-out signal is adjustable up to 2Vrms, allowing connection to active speakers or external amplifiers.
• Powerful Headphone Amplification: Delivers up to 1.5W of total power output into a 32Ω load, and up to 20Vpp at 300Ω, capable of driving both low and high impedance headphones.
• Precise Volume Control: ADC volume adjustment ensures smooth, fine-increment volume changes without undesirable noise or channel imbalances, accommodating various headphone sensitivities.

3. Setup Instructions

3.1 Unpacking and Placement

Carefully remove the FiiO K5 Pro from its packaging. Place the unit on a stable, flat surface away from direct sunlight, heat sources, and excessive moisture. Ensure adequate ventilation around the device.

3.2 Connecting Power

1. Connect the provided power adapter to the 'POWER IN DC 15V' port on the rear panel of the K5 Pro.
2. Plug the power adapter into a suitable wall outlet.

3.3 Input Connections

The K5 Pro offers multiple input options:

• USB IN: Connect your computer or compatible device using a USB cable to the 'USB IN' port for high-resolution audio playback.
• COAXIAL IN: Use a coaxial cable to connect to digital audio sources.
• OPTICAL IN: Use an optical (TOSLINK) cable to connect to digital audio sources.
• LINE IN (RCA): Connect analog audio sources using RCA cables to the 'LINE IN' ports.

Figure 2: Rear panel showing various input and output connections.

3.4 Output Connections

• Headphone Out (6.35mm): Plug your headphones into the 6.35mm jack on the front panel. A 3.5mm adapter may be used for headphones with smaller plugs.
• LINE OUT (RCA): Connect to active speakers or another amplifier using RCA cables.

4. Operating Instructions

4.1 Power On/Off and Volume Control

The large knob on the front panel serves as both the power switch and volume control. Rotate the knob clockwise until it clicks to power on the device. Continue rotating clockwise to increase volume, and counter-clockwise to decrease volume. Rotate counter-clockwise until it clicks to power off.

4.2 Input Selection

Use the 'INPUT' toggle switch on the front panel to select your desired audio source. The switch positions correspond to different inputs:

• 'U' (USB): For USB input.
• 'L' (Line In): For RCA Line In.
• 'S' (SPDIF): For Coaxial and Optical inputs.

4.3 Gain Selection

The 'GAIN' toggle switch allows you to adjust the amplification level to match your headphones' impedance and sensitivity. There are three gain levels:

• Low Gain
• Medium Gain
• High Gain

Select a lower gain for sensitive headphones and a higher gain for demanding, high-impedance headphones.

Figure 3: Front panel showing volume knob, input, and gain switches.

4.4 RGB Light Indicator

The RGB light around the volume knob indicates the current sample rate of the audio being played:

• Blue: 48kHz and below
• Green: Above 48kHz
• Red: DSD format

5. Maintenance

To ensure the longevity and optimal performance of your FiiO K5 Pro, follow these maintenance guidelines:

• Keep the device clean by wiping it with a soft, dry cloth. Avoid using harsh chemicals or abrasive materials.
• Do not expose the unit to extreme temperatures, humidity, or direct sunlight.
• Ensure proper ventilation to prevent overheating.
• Avoid dropping or subjecting the device to strong impacts.

6. Troubleshooting

If you encounter issues with your FiiO K5 Pro, refer to the following common troubleshooting steps:

• No Sound:
  • Check all cable connections (power, input, headphones/speakers).
  • Ensure the K5 Pro is powered on and the volume is not at minimum.
  • Verify the correct input source is selected using the 'INPUT' switch.
  • Confirm that your computer's audio output is set to the FiiO K5 Pro.
• Distorted Sound:
  • Reduce the volume on both the K5 Pro and your source device.
  • Adjust the 'GAIN' switch to a lower setting if your headphones are very sensitive.
  • Ensure the audio source file is not corrupted or of low quality.
• Intermittent Audio:
  • Check for loose cable connections.
  • Try a different input cable or port.
  • Ensure no other devices are interfering with the signal (e.g., electromagnetic interference).

If problems persist, consult the FiiO official support resources or contact customer service.

7. Specifications

8. Warranty and Support

The FiiO K5 Pro comes with a standard manufacturer's warranty. For detailed warranty information, please refer to the warranty card included with your product or visit the official FiiO website. For technical support, troubleshooting assistance beyond this manual, or service inquiries, please contact FiiO customer support through their official channels.

Always ensure you are using official FiiO accessories and following recommended guidelines to maintain warranty validity.