1. Introduction
Thank you for choosing the LOXJIE D40 Pro Decoder Headphone Amplifier. This device is designed to deliver high-fidelity audio performance, featuring an ES 9039MS Pro chip, MQA full decoding capabilities, and versatile connectivity options including Bluetooth 5.0. This manual provides essential information for setting up, operating, and maintaining your D40 Pro to ensure optimal sound quality and longevity.
Please read this manual thoroughly before using the product and keep it for future reference.
2. Safety Information
- Do not expose this unit to rain or moisture.
- Do not disassemble the unit. Refer all servicing to qualified personnel.
- Ensure proper ventilation around the unit. Do not block ventilation openings.
- Use only the power cable provided or a suitable replacement.
- Avoid placing the unit near heat sources or in direct sunlight.
- Disconnect the power cable during lightning storms or when unused for long periods.
3. Package Contents
Verify that all items listed below are included in your package:
Image: Contents of the LOXJIE D40 Pro retail box. This image displays the D40 Pro unit, a user manual, a power cable with various international plug adapters, a remote control, and a USB cable.
- LOXJIE D40 Pro Unit
- User Manual
- Power Cable (with interchangeable plugs)
- Remote Control
- USB Cable
4. Product Overview
4.1 Front Panel
Image: Front view of the LOXJIE D40 Pro. From left to right, it features power, function (FN), input selection, and output selection buttons, a central digital display, a large function knob, and three headphone output jacks (6.35mm, 4.4mm, and balanced XLR).
- Power Button: Turns the unit on or off.
- FN (Function) Button: Used to switch filter modes or access other functions.
- Input Selection Button: Cycles through available input sources.
- Output Selection Button: Selects between different output modes (e.g., headphone, line out).
- Display Screen: Shows current sample rate, input, and other status information.
- Function Knob: Adjusts volume, navigates menus, or confirms selections.
- 6.35mm Headphone Jack: Standard unbalanced headphone output.
- 4.4mm Headphone Jack: Balanced headphone output.
- Balanced Headphone Jack (XLR 4-pin): Professional balanced headphone output.
4.2 Rear Panel
Image: Rear view of the LOXJIE D40 Pro with numbered labels indicating various input and output ports. These include RCA outputs, XLR outputs, AES/EBU input, I2S input, Bluetooth antenna, Optical input, Coaxial input, USB input, and the main power input.
- RCA Output: Unbalanced analog audio output.
- XLR Output: Balanced analog audio output.
- AES/EBU Input: Professional digital audio input.
- Bluetooth Antenna: For wireless Bluetooth connectivity.
- I2S Input: High-resolution digital audio input.
- Optical Input: Digital audio input (Toslink).
- Coaxial Input: Digital audio input (RCA).
- USB Input: For connecting to a computer or other USB audio source.
- Power Input (100-240V AC): Connects to the main power supply.
4.3 Remote Control
Image: The LOXJIE D40 Pro remote control, showing buttons for power, screen off, mute, navigation (up, down, left, right, OK/Menu), EQ, Mode, Input, Output, and Volume +/-. The remote allows for convenient control of the unit's functions from a distance.
The included remote control provides convenient access to all major functions of the D40 Pro:
- ON/OFF: Power on/off.
- Screen off: Toggles display brightness or turns off the screen.
- Mute: Mutes/unmutes audio output.
- Navigation Buttons (Up/Down/Left/Right/OK/Menu): For menu navigation and selection.
- EQ/Filter Switch: Cycles through digital filter modes.
- Mode: Switches between different operating modes.
- Input Switch: Selects input source.
- Output Switch: Selects output type.
- Volume +/-: Adjusts output volume.
5. Setup
5.1 Power Connection
- Ensure the D40 Pro is placed on a stable, level surface with adequate ventilation.
- Connect the provided power cable to the AC IN port on the rear panel of the D40 Pro.
- Plug the other end of the power cable into a suitable wall outlet (100-240V AC).
5.2 Audio Connections
The D40 Pro offers a variety of input and output options. Choose the appropriate cables and connections for your audio system.
Input Connections:
- USB Input: Connect a USB cable from your computer or digital audio player to the USB input on the D40 Pro. For Windows users, it may be necessary to install a specific driver from the LOXJIE official website for optimal performance and high-resolution audio playback.
- Optical/Coaxial Input: Connect an optical (Toslink) or coaxial (RCA) cable from your digital audio source (e.g., CD player, TV, game console) to the corresponding input on the D40 Pro.
- AES/EBU Input: For professional audio equipment, connect an AES/EBU cable to the dedicated input.
- I2S Input: Connect compatible I2S sources for high-fidelity digital audio transmission. The D40 Pro supports multi-standard I2S configurations (HD1/HD2).
Image: A diagram illustrating the I2S multi-standard options (Normal HD1 and Inverted HD2) supported by the LOXJIE D40 Pro, showing pin configurations and how to select them on the unit's display.
- Bluetooth: Ensure the Bluetooth antenna is securely attached to the rear panel for stable wireless connection.
Output Connections:
- RCA Output: Connect RCA cables from the D40 Pro to your amplifier or active speakers for unbalanced analog audio.
- XLR Output: Connect XLR cables from the D40 Pro to your balanced amplifier or active speakers for balanced analog audio.
- Headphone Outputs: Plug your headphones into the 6.35mm, 4.4mm, or balanced XLR headphone jacks on the front panel.
Image: A visual representation highlighting the three headphone output options on the LOXJIE D40 Pro: a 4-core balanced Canon port, a 6.35mm unbalanced jack, and a 4.4mm balanced jack, indicating independent volume control and power output.
6. Operating Instructions
6.1 Power On/Off
Press the Power button on the front panel or the remote control to turn the unit on or off.
6.2 Input Selection
Press the Input Selection button on the front panel or the remote control to cycle through available input sources (USB, Optical, Coaxial, AES/EBU, I2S, Bluetooth).
6.3 Volume Control
Rotate the Function Knob on the front panel or use the Volume +/- buttons on the remote control to adjust the output volume. The volume level will be displayed on the screen.
6.4 Headphone Output
When headphones are connected, the D40 Pro will automatically route audio to the selected headphone output. Ensure the correct headphone jack is used for your headphone type (unbalanced 6.35mm, balanced 4.4mm, or balanced XLR).
6.5 Bluetooth Pairing
- Select Bluetooth as the input source on the D40 Pro.
- On your mobile device, search for Bluetooth devices and select "LOXJIE D40 Pro" to pair.
- Once paired, audio from your device will be streamed to the D40 Pro. The D40 Pro supports high-quality codecs like LDAC.
Image: A graphic demonstrating the LOXJIE D40 Pro's Bluetooth 5.1 capabilities, highlighting its support for LDAC codec for high-resolution wireless audio transmission, with a typical range of 0-10 meters.
6.6 Display Brightness
Press the Screen off button on the remote control to adjust the display brightness or turn off the screen completely.
6.7 Digital Filter Modes
The D40 Pro features multiple digital filter modes to fine-tune the sound signature. Use the FN button on the front panel or the EQ/Filter Switch button on the remote to cycle through these options. Refer to the on-screen display for the currently selected filter.
6.8 MQA Decoding
The D40 Pro supports MQA (Master Quality Authenticated) full decoding via its USB input, allowing you to experience the full quality of MQA music files. It also supports MQA-CD playback via optical and coaxial inputs, enabling high-quality MQA audio from compatible CD players.
Image: The LOXJIE D40 Pro unit with text indicating its support for MQA full decoding via USB input and MQA-CD via optical/coaxial inputs, allowing for high-resolution audio playback.
7. Key Features
- Advanced XMOS XU-316 Processor: Supports PCM up to 32bit/768kHz and DSD up to DSD512 for high-resolution audio playback.
- Qualcomm Bluetooth 5.0 Chip: Provides high-quality wireless audio streaming with support for LDAC 24bit/96kHz, aptX/HD, SBC, and AAC codecs.
- Fully Balanced Circuit Design: The headphone amplifier section features a fully balanced circuit for high power output and extremely low distortion.
- Ultra-Low Phase Noise Clock Processing: Optimized circuitry ensures ultra-low clock jitter for precise audio reproduction.
- Advanced Power Supply Design: Built-in low-noise power supply processing, along with discrete component linear regulated power supplies, provides clean and stable power to analog circuits.
- Firmware Upgrade Function: Allows users to update the system and USB firmware for future enhancements and compatibility.
- High-Quality Components: Features high-quality gold-plated input and output connection terminals for reliable signal transfer.
- Comprehensive Remote Control: A full-featured remote control is included for convenient operation.
8. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use liquid cleaners or aerosols.
- Storage: If storing the unit for an extended period, disconnect it from power and store it in a cool, dry place away from direct sunlight and extreme temperatures.
- Ventilation: Ensure the ventilation openings are clear of dust and obstructions to prevent overheating.
9. Troubleshooting
If you encounter issues with your LOXJIE D40 Pro, please refer to the following common troubleshooting steps:
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Power cable not connected; power outlet issue. | Ensure power cable is securely connected to the unit and a working power outlet. |
| No sound output | Incorrect input selected; volume too low; faulty cables; output mode incorrect. | Verify correct input source is selected. Increase volume. Check all audio cables for secure connection and integrity. Ensure the correct output mode (e.g., headphone or line out) is selected. |
| No sound from headphones | Headphones not fully plugged in; incorrect headphone jack used. | Ensure headphones are fully inserted into the correct jack. Try a different headphone jack if available. |
| Bluetooth not connecting | D40 Pro not in pairing mode; device too far; interference. | Ensure Bluetooth input is selected on D40 Pro. Move device closer. Avoid sources of strong electromagnetic interference. |
| USB audio issues (e.g., no sound, low quality) | Missing or incorrect USB driver (for Windows); incorrect audio settings on computer. | Install the latest USB driver from the LOXJIE official website. Check your computer's sound settings to ensure D40 Pro is selected as the output device and sample rate/bit depth are correctly configured. |
Firmware Update
The D40 Pro supports firmware updates. Visit the official LOXJIE website for the latest firmware versions and instructions on how to perform an update. This can resolve bugs and introduce new features.
10. Specifications
| Feature | Specification |
|---|---|
| DAC Chip | ES 9039MS Pro |
| USB Processor | XMOS XU-316 (3rd Gen) |
| PCM Support | Up to 32bit/768kHz |
| DSD Support | Up to DSD512 |
| MQA Support | Full MQA Decoding (USB), MQA-CD (Optical/Coaxial) |
| Bluetooth Version | 5.0 |
| Bluetooth Codecs | LDAC (24bit/96kHz), aptX/HD, SBC, AAC |
| Headphone Output Power | High power output (e.g., 350mW x 2 into 600Ω) |
| Package Dimensions | 13.94 x 9.61 x 3.23 inches |
| Item Weight | 3.65 pounds |
| Power Input | 100-240V AC |
11. Warranty and Support
The LOXJIE D40 Pro comes with a one-year warranty from the date of purchase. This warranty covers manufacturing defects and malfunctions under normal use.
If you encounter any problems during the use of your product, or require technical assistance, please contact the seller or LOXJIE customer support. Please retain your proof of purchase for warranty claims.
