1. Introduction
The Aune X8 18th Anniversary Edition-BT is a high-performance Digital-to-Analog Converter (DAC) designed for audiophiles. This device features high-resolution audio decoding up to 32bit/768k and DSD512, a unique op-amp replaceable design for sound customization, and multiple input/output options including USB, coaxial, optical, Bluetooth 5.1 (with aptX-HD and LDAC support), RCA preamp/line out, and balanced TRS output. This manual provides detailed instructions for setup, operation, and maintenance of your Aune X8 XVIII-BT DAC.
Image 1.1: Front view of the Aune X8 18th Anniversary Edition-BT DAC.
2. Product Overview
2.1 Key Features
- High-Resolution Audio: Supports up to 32bit/768k PCM and DSD512.
- Op-Amp Replaceable Design: Allows users to customize sound characteristics by replacing the dual op-amp.
- FPGA Core Design: Utilizes FPGA technology for purer digital signals and enhanced sound quality.
- Versatile Inputs: USB, Optical, Coaxial, and Bluetooth 5.1 (aptX-HD, LDAC).
- Multiple Outputs: RCA Preamp Out, RCA Line Out, and Balanced TRS Preamp Out.
- 7 Filter Modes: Provides various sound filtering options.
2.2 Controls and Connections
Image 2.1: Front and Rear Panel Layout of the Aune X8 XVIII-BT DAC.
Front Panel:
- Selection Button: Used to cycle through input sources.
- Indicator Lights: Display the currently selected input (USB, OPT, COAX, A, B, C, D, MN).
- Volume Knob: Controls the output volume for the preamp output.
Rear Panel:
- TRS Output (L/R): Balanced TRS preamp output for professional audio connections.
- RCA Preamp Out (L/R): Variable RCA output for connecting to power amplifiers or active speakers.
- RCA Line Out (L/R): Fixed level RCA output for connecting to integrated amplifiers or preamplifiers.
- Coaxial Input: Digital audio input.
- Optical Input: Digital audio input.
- USB Input: For connecting to computers or portable devices.
- Bluetooth Antenna (ANT): For Bluetooth signal reception (Bluetooth version only).
- Power Switch (SW): Turns the device on or off.
- Power Input (DC): Connects to the provided power adapter.
3. Setup
3.1 Initial Connection
- Connect the provided power adapter to the Power Input (DC) on the rear panel and then to a suitable power outlet.
- Connect your audio output device (e.g., power amplifier, active speakers, headphone amplifier) to the appropriate output on the X8 XVIII-BT DAC:
- For variable output, use RCA Preamp Out or TRS Output.
- For fixed line level output, use RCA Line Out.
3.2 Connecting Input Sources
The Aune X8 XVIII-BT DAC supports various digital audio inputs:
- USB Input: Connect a USB cable from your computer, smartphone, tablet, or portable music player (with appropriate cables) to the USB Input on the rear panel.
- Optical Input: Connect an optical cable from your digital audio source (e.g., TV, CD player, game console) to the Optical Input.
- Coaxial Input: Connect a coaxial cable from your digital audio source to the Coaxial Input.
- Bluetooth Input: Ensure the Bluetooth antenna is securely attached to the ANT connector on the rear panel.
Image 3.1: Multi-Connectivity Diagram.
4. Operation
4.1 Power On/Off
Flip the Power Switch (SW) on the rear panel to the 'ON' position to power on the device. Flip it to 'OFF' to power off.
4.2 Input Selection
Press the Selection Button on the front panel to cycle through the available input sources (USB, OPT, COAX, Bluetooth). The corresponding indicator light will illuminate to show the active input.
4.3 Volume Control
The Volume Knob on the front panel controls the output level of the RCA Preamp Out and TRS Output. Rotate clockwise to increase volume and counter-clockwise to decrease volume. The RCA Line Out provides a fixed output level and is not affected by the volume knob.
4.4 Filter Modes
The X8 XVIII-BT DAC features 7 digital filter modes. These modes can be selected to fine-tune the sound characteristics according to your preference. Refer to the product's detailed specifications or Aune's official website for specific instructions on how to cycle through and select these filter modes, as the method may vary.
4.5 Bluetooth Pairing (Bluetooth Version Only)
- Ensure the Bluetooth antenna is connected.
- Select the Bluetooth input using the Selection Button.
- On your mobile device (smartphone, tablet, laptop), enable Bluetooth and search for available devices.
- Select "Aune X8 XVIII-BT" (or similar) from the list of devices to pair.
- Once paired, audio from your device will be streamed to the X8 XVIII-BT DAC.
Image 4.1: Bluetooth connectivity with portable devices.
5. Advanced Features
5.1 Op-Amp Replacement
The Aune X8 XVIII-BT DAC allows for the replacement of its dual op-amp, enabling users to customize the sound signature. This feature is intended for experienced users. Exercise caution when handling electronic components.
- Ensure the device is powered off and disconnected from the power supply.
- Carefully open the device casing according to the specific instructions provided with your unit or by Aune support.
- Locate the existing dual op-amp.
- Using an appropriate tool (e.g., op-amp puller), gently remove the op-amp. Note its orientation.
- Insert the new compatible dual op-amp, ensuring correct orientation and pin alignment. Do not force the op-amp into place.
- Close the device casing securely.
Image 5.1: Op-Amp replaceable design.
Different dual op-amps can significantly alter the sound characteristics. Experiment with various compatible op-amps to find your preferred sound.
5.2 FPGA Core Design
The X8 XVIII-BT DAC incorporates Aune's proprietary FPGA (Field-Programmable Gate Array) technology. This design is implemented to process digital signals with high precision, resulting in a purer and more accurate audio reproduction.
Image 5.2: Illustration of FPGA Core Design.
6. Connectivity Scenarios
6.1 PC HiFi Setup
Connect the X8 XVIII-BT DAC to your computer via USB. This allows the DAC to process high-resolution audio files (up to 32bit/768k DSD512) from your computer, enhancing the sound quality for active speakers or headphone amplifiers.
Image 6.1: PC HiFi setup with Aune X8 DAC.
6.2 Coaxial/Optical Input Setup
Utilize the coaxial or optical inputs to connect to digital transports or players. This setup supports PCM up to 384k and DSD128, providing a high-quality audio system without requiring a PC.
Image 6.2: Coaxial/Optical input setup.
6.3 Portable Device Connectivity
The X8 XVIII-BT DAC can be connected to various portable devices such as iPhones, Android phones, iPads, or portable music players via USB (corresponding cables may be needed). This provides an instant improvement in sound quality for your mobile audio experience.
Image 6.3: Portable device connectivity.
7. Specifications
| Feature | Specification |
|---|---|
| Model | X8 18th Anniversary Edition-BT |
| Decoding Capability (USB) | PCM 32bit/768kHz, DSD512 |
| Decoding Capability (Coaxial/Optical) | PCM 32bit/384kHz, DSD128 (DoP) |
| Bluetooth Version | 5.1 |
| Bluetooth Codecs | aptX-HD, LDAC, AAC |
| Outputs | RCA Preamp Out, RCA Line Out, Balanced TRS Preamp Out |
| Inputs | USB, Coaxial, Optical, Bluetooth |
| Op-Amp | Replaceable Dual Op-Amp |
| Filter Modes | 7 Digital Filter Modes |
| Dimensions | 9.61 x 7.17 x 4.41 inches (Package Dimensions) |
| Weight | 3.83 pounds (Item Weight) |
Image 7.1: Key Features Overview.
8. Troubleshooting
- No Power: Ensure the power adapter is securely connected to both the device and a working power outlet. Check the power switch on the rear panel.
- No Sound:
- Verify that the correct input source is selected on the DAC.
- Check all audio cable connections between the DAC and your amplifier/speakers.
- If using preamp outputs, ensure the volume knob is not set to minimum.
- Confirm that your amplifier/speakers are powered on and set to the correct input.
- Intermittent Audio/Dropouts:
- Check the quality and secureness of your digital input cables (USB, optical, coaxial).
- For Bluetooth, ensure your source device is within range and there is no interference.
- Try a different input source or cable to isolate the issue.
- Bluetooth Connection Issues:
- Ensure the Bluetooth antenna is properly attached.
- Make sure the DAC is in Bluetooth input mode.
- Forget the device on your source device's Bluetooth settings and attempt to re-pair.
- Sound Distortion:
- Check if the input signal level is too high, causing clipping.
- Ensure all connections are secure and free from damage.
- If using a replaceable op-amp, ensure it is correctly seated and compatible.
9. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the device. Avoid using liquid cleaners or abrasive materials.
- Placement: Place the device on a stable, flat surface with adequate ventilation. Avoid direct sunlight, heat sources, and high humidity.
- Cable Management: Ensure cables are not excessively bent or strained to prevent damage.
10. Warranty and Support
10.1 Warranty Information
All Aune products come with a 2-year after-sales service. This warranty covers manufacturing defects and issues arising from normal use.
10.2 After-Sales Service
Aune provides a comprehensive after-sales system. Should you encounter any problems during the use of your product, please contact Aune customer support. They will assist you promptly and provide a satisfactory resolution.
10.3 Product Condition
All Aune items are new and carefully packaged. If you observe any signs of use upon receiving your product, it may be due to transit or warehouse handling. Please communicate with customer support to address such concerns.
11. Product Video
Video 11.1: Official product video showcasing the Aune X8 18th Anniversary Edition DAC's features and design. This video provides a visual overview of the device and its capabilities.
