HIFIMAN EF600 Desktop Balanced Headphone DAC & Amplifier User Manual

1. Introduction

The HIFIMAN EF600 is a high-performance desktop balanced headphone DAC (Digital-to-Analog Converter) and amplifier. It integrates HIFIMAN's HYMALAYA PRO R2R DAC technology with a powerful headphone amplifier, offering versatile connectivity options including XLR, RCA, 6.35mm outputs, and high-resolution Bluetooth audio. Designed for home audio environments, the EF600 also functions as a headphone stand, combining functionality with a distinctive aesthetic.

Figure 1.1: Front view of the HIFIMAN EF600 unit.

2. Safety Information

• Read all instructions before operating the device.
• Keep the device away from water, moisture, and extreme temperatures.
• Do not attempt to disassemble or repair the unit yourself. Refer all servicing to qualified personnel.
• Ensure proper ventilation around the unit to prevent overheating.
• Use only the specified power supply and cables.
• Adjust volume levels responsibly to protect your hearing.

3. Package Contents

Verify that all items are present in the package:

• HIFIMAN EF600 Unit
• Power Cable
• USB Cable (Type-A to Type-B or Type-C)
• User Manual (this document)

4. Product Features

• HYMALAYA PRO R2R DAC: Features advanced R2R DAC technology for low distortion, low noise, and efficient power consumption.
• Powerful Balanced Output: Delivers 5.12W per channel, suitable for driving a wide range of headphones.
• Optimized Thermal Design: Engineered with a tower case design for convection cooling, placing the center of gravity at the bottom and cooling at the top for stable operation.
• Versatile Connectivity: Includes USB-B, USB-C, Coaxial, RCA, and Balanced XLR inputs, along with XLR 4-pin balanced and 6.35mm single-ended headphone outputs, and XLR balanced/RCA single-ended line outputs.
• High-Resolution Bluetooth: Supports multiple Bluetooth codecs, including aptX-HD, for high-fidelity wireless audio streaming.
• Integrated Headphone Stand: The unit's design allows it to function as a convenient headphone stand.

Figure 4.1: Internal design and thermal management of the EF600.

5. Controls and Connections

5.1 Front Panel

Figure 5.1: Front panel controls and indicators.

• Gain/OS Indicators: Display current gain mode (High/Low) and Oversampling (OS) or Non-Oversampling (NOS) status.
• Input Indicators: Show the active input source (USB/Coaxial, Bluetooth, RCA, Balanced In).
• Input Selectors (Left/Right): Buttons to cycle through available input sources.
• Volume Control: Rotary knob to adjust output volume.
• XLR 4-Pin Balanced Headphone Output: For balanced headphones.
• 6.35mm Single-ended Headphone Output: For single-ended headphones.

5.2 Rear Panel

Figure 5.2: Rear panel connections.

• Bluetooth Antenna: For wireless Bluetooth connectivity.
• USB-B Input: Connect to a computer or other USB audio source.
• Type-C Input: Connect to devices with USB-C output.
• Coaxial Input: Digital audio input.
• XLR Balanced Input (L/R): Analog balanced audio input.
• RCA Single-ended Input (L/R): Analog single-ended audio input.
• XLR Balanced Output (L/R): Analog balanced line output to external amplifiers or active speakers.
• Power Connector: For connecting the AC power cable.
• Power Switch: To turn the unit on or off.

Figure 5.3: Front and rear panel overview with OS compatibility notes.

6. Setup

6.1 Placement

Place the EF600 on a stable, flat surface. Ensure adequate space around the unit for proper ventilation, especially at the top, to facilitate convection cooling. The unit's design allows it to serve as a headphone stand, providing a convenient storage solution for your headphones.

Figure 6.1: EF600 used as a headphone stand.

6.2 Power Connection

1. Before connecting the power cable, locate the AC 115V/230V voltage selector switch on the rear panel.
2. Ensure the switch is set to the correct voltage for your region (e.g., AC 115 for North America, AC 230 for Europe).


Figure 6.2: AC Voltage Selector.

3. Connect the provided power cable to the power connector on the rear panel and then to a suitable AC power outlet.

6.3 Connecting Audio Sources

The EF600 offers multiple input options:

• USB-B / USB-C: Connect your computer, smartphone, or other digital audio source using a compatible USB cable. For Windows 10 and earlier operating systems, additional drivers may be required.
• Coaxial: Connect digital audio sources such as CD players or media streamers via a coaxial cable.
• RCA Single-ended Input: Connect analog audio sources like preamplifiers or phono stages using RCA cables.
• XLR Balanced Input: For high-quality analog balanced audio input from compatible sources.

6.4 Connecting Headphones or External Amplifiers

The EF600 provides several output options:

• XLR 4-Pin Balanced Headphone Output: For headphones equipped with a 4-pin XLR balanced connector.
• 6.35mm Single-ended Headphone Output: For headphones with a standard 6.35mm (1/4 inch) single-ended connector.
• XLR Balanced Output (L/R): To connect the EF600's DAC output to an external balanced amplifier or active speakers.
• RCA Single-ended Output (L/R): To connect the EF600's DAC output to an external single-ended amplifier or active speakers.

7. Operation

7.1 Power On/Off

Flip the power switch on the rear panel to the 'ON' position to power on the unit. Flip it to 'OFF' to power down.

7.2 Input Selection

Use the Left and Right Input Selector buttons on the front panel to cycle through the available input sources (USB/Coaxial, Bluetooth, RCA, Balanced In). The active input will be indicated by the corresponding LED on the front panel.

7.3 Gain Settings

The EF600 features different gain modes (High Gain, Low Gain) and Oversampling (OS) or Non-Oversampling (NOS) modes. These settings can be selected via the input selector buttons, and their status is indicated by the LEDs on the front panel. Experiment with these settings to find the optimal sound for your headphones and preferences.

7.4 Volume Control

Rotate the large volume knob on the front panel to adjust the output level of the connected headphones or line outputs. Start with a low volume and gradually increase it to a comfortable listening level.

7.5 Bluetooth Pairing

1. Ensure the Bluetooth antenna is securely attached to the rear panel.
2. Select Bluetooth as the input source using the front panel input selector. The Bluetooth indicator LED will illuminate.
3. On your source device (e.g., smartphone, tablet), enable Bluetooth and search for available devices.
4. Select 'HIFIMAN EF600' from the list of devices to pair.
5. Once paired, the Bluetooth indicator LED on the EF600 may change status (e.g., solid light) to confirm connection.
6. The EF600 supports various Bluetooth codecs, including aptX-HD, for high-quality wireless audio.

Figure 7.1: Supported Bluetooth codecs.

8. Maintenance

• Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Avoid using liquid cleaners or solvents.
• Ventilation: Ensure that the ventilation openings are not blocked by dust or debris. Periodically clean them with a soft brush or compressed air.
• Storage: If storing the unit for an extended period, disconnect it from power and store it in a cool, dry place.

9. Troubleshooting

10. Specifications

Figure 10.1: Product Dimensions.

11. Warranty and Support

HIFIMAN products are designed for reliability and performance. For warranty information, technical support, or service inquiries, please refer to the official HIFIMAN website or contact their customer service directly. Keep your proof of purchase for warranty claims.