CAYIN RU6 Portable USB DAC/Amp Dongle User Manual

1. Introduction

The CAYIN RU6 is a portable USB Digital-to-Analog Converter (DAC) and headphone amplifier designed to deliver high-fidelity audio from various digital sources. Featuring a 24-bit Discrete R-2R Ladder DAC, it supports high-resolution audio formats including PCM up to 384kHz and DSD up to 256. Its compact design and versatile connectivity make it an ideal companion for enhancing your audio experience on the go.

2. Package Contents

Please verify that all items are present in the package:

• CAYIN RU6 Portable USB DAC/Amp Dongle
• USB-C to USB-C Interconnect Cable
• User Manual (this document)
• Warranty Card (if applicable)

Note: Optional accessories such as a leather case or USB-C to Lightning cable are sold separately.

3. Product Overview

Familiarize yourself with the components of your CAYIN RU6 device.

Figure 3.1: Angled view of the CAYIN RU6, showcasing its compact design and OLED display.

3.1 Front Panel and Display

• OLED Display: Shows current playback information, sample rate, volume level, and operating mode.
• Volume Buttons: Used to adjust the audio output level.

3.2 Top Panel

Figure 3.2: Top view of the CAYIN RU6, highlighting the 'Discrete R-2R RU6' branding.

• Discrete R-2R RU6 Branding: Indicates the core DAC technology.

3.3 Bottom Panel (USB-C Input)

Figure 3.3: Bottom view of the CAYIN RU6, showing the USB-C input port.

• USB-C Input: Connects to your source device (smartphone, tablet, computer, DAP) for power and digital audio signal.

3.4 Top Panel (Headphone Outputs)

Figure 3.4: Top view of the CAYIN RU6, displaying the 3.5mm unbalanced and 4.4mm balanced headphone output jacks.

• 3.5mm Unbalanced Headphone Output: Standard single-ended output for headphones.
• 4.4mm Balanced Headphone Output: Provides a balanced audio signal for compatible headphones, offering improved channel separation and power.

4. Setup

4.1 Connecting to a Source Device

1. Connect the RU6: Use the provided USB-C to USB-C cable to connect the CAYIN RU6 to your smartphone, tablet, computer (macOS/Windows), or Digital Audio Player (DAP).
2. Power On: The RU6 will typically power on automatically when connected to a compatible source device that supplies power via USB. The OLED display will illuminate.
3. Connect Headphones: Plug your headphones into either the 3.5mm unbalanced or 4.4mm balanced output jack on the RU6. Ensure the connection is secure.

4.2 Driver Installation (Windows Only)

For Windows operating systems, a dedicated driver may be required for optimal performance and DSD playback. macOS, iOS, and Android devices are generally plug-and-play.

• Visit the official CAYIN website (www.cayin.cn) to download the latest USB DAC driver for the RU6.
• Follow the on-screen instructions to install the driver.
• After installation, select the CAYIN RU6 as the default audio output device in your computer's sound settings.

5. Operation

5.1 Basic Audio Playback

1. Ensure the RU6 is connected to your source device and headphones are plugged in.
2. Start playing audio from your source device. The RU6 OLED display will show the current sample rate and volume level.
3. Adjust the volume using the physical volume buttons on the RU6. The RU6 features a proprietary discrete resistor array for 0-99 volume steps, providing precise control.

5.2 Operating Modes: NOS and OS

The CAYIN RU6 offers two distinct operating modes for its R-2R DAC:

• NOS (Non-Oversampling) Mode: This mode bypasses digital filters, providing a raw, unfiltered audio signal. It is often preferred by audiophiles for its natural and organic sound reproduction.
• OS (Oversampling) Mode: This mode applies digital filters to the audio signal, which can reduce aliasing and improve signal-to-noise ratio. It generally results in a smoother, more refined sound.

To switch between NOS and OS modes, refer to the device's menu system accessible via the hardware buttons. The current mode will be indicated on the OLED display.

5.3 Gain Settings

The RU6 includes high and low gain settings to optimize output power for various headphones.

• Low Gain: Suitable for sensitive in-ear monitors (IEMs) and low-impedance headphones, preventing excessive volume and potential distortion.
• High Gain: Provides more power for demanding, high-impedance headphones, ensuring adequate volume and dynamic range.

Access the gain setting through the device's menu. Select the appropriate gain level based on your headphones for the best listening experience.

6. Maintenance

6.1 Cleaning

• Gently wipe the device with a soft, dry, lint-free cloth.
• Do not use liquid cleaners, aerosols, or solvents, as these may damage the finish or internal components.

6.2 Storage

• Store the RU6 in a cool, dry place away from direct sunlight and extreme temperatures.
• When not in use, disconnect it from all devices to prevent accidental power draw.

7. Troubleshooting

8. Specifications

9. Safety Information

• Do not expose the device to water, moisture, or extreme temperatures.
• Avoid dropping or subjecting the device to strong impacts.
• Do not attempt to disassemble or modify the device. This will void the warranty.
• Prolonged listening at high volume levels can cause permanent hearing damage. Adjust volume to a safe level.
• Keep out of reach of children.

10. Warranty and Support

CAYIN products are covered by a limited warranty. Please refer to the warranty card included in your package for specific terms and conditions. For technical support, service, or further inquiries, please visit the official CAYIN website or contact your local distributor.

Official CAYIN Website: www.cayin.cn

CAYIN Store on Amazon: Visit the CAYIN Store