1. Introduction
This manual provides instructions for the safe and effective use of your Questyle M15i Portable USB C DAC Headphone Amplifier. Please read this manual thoroughly before using the product to ensure optimal performance and longevity.
The Questyle M15i, a compact and powerful device designed to enhance your audio experience.
2. Package Contents
Verify that all items listed below are included in your product package:
- Questyle M15i USB DAC Headphone Amplifier x1
- Type-C to Type-C cable x1
- Type-C to USB-A Converter x1
- User Manual x1
- Warranty Card x1
The Questyle M15i package includes the M15i unit, a Type-C to Type-C cable, a Type-C to USB-A converter, and the user manual.
3. Product Overview
Familiarize yourself with the physical components and indicators of your M15i device.
The M15i features a USB-C input, 3.5mm single-ended output, 4.4mm balanced output, and a gain switch for adjusting output levels.
Data Status Indicator
The M15i features LED indicators to show the current data sampling rate:
- 1 LED on: Sampling rate ≤ 48kHz
- 2 LEDs on: Sampling rate > 48kHz
Gain Indicator
The M15i offers two gain modes, indicated by LEDs:
- 1 LED on: Standard gain
- 2 LEDs on: High gain
LED indicators on the M15i provide visual feedback for data sampling rate and selected gain mode.
4. Setup
Follow these steps to connect your M15i to your audio source and headphones.
Step 1: Prepare Your Audio Source
For optimal performance, ensure your audio source is configured for lossless audio quality, if supported.
To enable lossless audio on iOS devices, navigate to Settings > Music > Audio Quality and select 'Lossless Audio'.
Step 2: Connect the M15i to Your Device
Use the provided Type-C to Type-C cable to connect the M15i to your smartphone, tablet, or computer. If your device uses a USB-A port, use the included Type-C to USB-A converter.
Connect the M15i to your mobile device using the appropriate USB cable.
Step 3: Connect Headphones
Plug your headphones into either the 3.5mm single-ended output or the 4.4mm balanced output on the M15i.
Once connected to your source device, plug your headphones into the M15i's output jack.
5. Operating Instructions
The M15i is designed for plug-and-play functionality. No additional drivers are typically required for most compatible devices.
Playing Music
Once connected, simply play audio from your device. The M15i will automatically process the audio signal, providing enhanced sound quality.
Enjoy high-fidelity audio playback by simply connecting your M15i and playing music.
Adjusting Gain
The M15i features a manual gain adjustment switch on its side. Adjust the gain setting according to your headphones' characteristics and personal preference:
- Standard Gain: Suitable for most sensitive headphones and in-ear monitors (IEMs).
- High Gain: Recommended for headphones with higher impedance or lower sensitivity that require more power.
6. Compatibility
The Questyle M15i offers broad compatibility with various operating systems and music platforms:
- Operating Systems: iOS, Harmony OS, Android (versions 5.1+), Windows (versions 10+), macOS.
- Music Platforms: Compatible with popular streaming services and local music playback applications.
Note: When connecting to Lightning interface devices (e.g., older iPhones/iPads), an additional MFi-certified Lightning to Type-C adapter (such as the Questyle LTC02) is required and sold separately.
The M15i is compatible with a wide range of devices and operating systems, offering plug-and-play functionality.
7. Maintenance
Proper care and maintenance will help prolong the life of your M15i.
- Keep the device dry. Avoid exposure to moisture, liquids, or extreme temperatures.
- Clean the exterior with a soft, dry cloth. Do not use harsh chemicals, solvents, or abrasive materials.
- Protect the USB-C and audio ports from dust and debris when not in use.
- Avoid dropping the device or subjecting it to strong impacts.
8. Troubleshooting
If you encounter any issues with your M15i, please refer to the following common problems and solutions.
No Sound Output
- Ensure the M15i is securely connected to both the source device and headphones.
- Verify that the volume on your source device is not muted or set too low.
- Check if your headphones are functioning correctly with other devices.
- Confirm that your source device's audio output is directed to the M15i (e.g., in system sound settings on a PC).
Intermittent Disconnections
- Ensure the USB-C cable is fully inserted into both the M15i and the source device, and that the cable is not damaged.
- Try using a different USB-C cable if available.
- For iOS devices, ensure you are using an MFi-certified Lightning to Type-C adapter if applicable, and that it is securely connected.
Device Not Recognized
- Disconnect and reconnect the M15i from your source device.
- Restart your source device (smartphone, tablet, or computer).
- For Windows PCs, ensure your operating system is updated to Windows 10 or later.
- If issues persist, contact Questyle customer support.
9. Specifications
The following are the technical specifications for the Questyle M15i:
| Feature | Detail |
|---|---|
| Model Name | M15i |
| DAC Chip | ESS ES9281AC |
| PCM Support | Up to 768kHz/32bit |
| DSD Support | Up to DSD512 |
| Outputs | 3.5mm Single-ended, 4.4mm Balanced |
| Amplifier Technology | Questyle Patented Current Mode Amplifier (CMA) |
| THD+N | 0.0003% |
| Impedance Adaptive Range | 8ohm ∼ 600ohm |
| Connectivity | Wired (USB-C) |
| Dimensions | 2.44 x 0.47 x 1.09 inches |
| Item Weight | 3.52 ounces |
| Material | Metal |
| UPC | 799194388246 |
10. Warranty and Support
Product Warranty
The Questyle M15i comes with a standard manufacturer's warranty. Please refer to the warranty card included in your package for specific terms and conditions, including coverage duration and limitations.
The package includes a warranty card with detailed information regarding product coverage and support.
Customer Support
For technical assistance, troubleshooting, or warranty inquiries, please contact Questyle customer service. You can find contact information on the official Questyle website or through your purchase platform.
