iFi Pro iDSD 4.4mm Desktop DAC and Headphone Amplifier User Manual

1. Introduction

The iFi Pro iDSD 4.4mm is a versatile high-resolution audio device designed for discerning audiophiles. It functions as a Digital-to-Analog Converter (DAC), a tube/solid-state headphone amplifier, and a wireless audio streamer. This manual provides essential information for setting up, operating, and maintaining your Pro iDSD to ensure optimal performance and longevity.

Figure 1: Front view of the iFi Pro iDSD 4.4mm unit, showcasing its controls and display.

2. Safety Information

• Power Supply: Use only the provided power adapter. Ensure the voltage matches your region's power supply.
• Ventilation: Do not block ventilation openings. Ensure adequate airflow around the unit to prevent overheating.
• Moisture: Keep the device away from water, moisture, and high humidity. Do not operate with wet hands.
• Cleaning: Disconnect power before cleaning. Use a dry, soft cloth. Avoid liquid cleaners or aerosols.
• Servicing: Do not attempt to service the unit yourself. Refer all servicing to qualified service personnel.
• Placement: Place the unit on a stable, level surface. Avoid placing it near heat sources or in direct sunlight.

3. Package Contents

Verify that all items are present in your iFi Pro iDSD package:

Figure 2: The iFi Pro iDSD package contents, including the main unit, remote control, various cables, and user documentation.

• iFi Pro iDSD 4.4mm Unit
• iFi Remote Control
• Power Adapter
• USB 3.0 Cable
• RCA Interconnect Cables
• WiFi Antenna
• iFi iPower Power Supply
• User Manual and Warranty Card

4. Front Panel Controls and Indicators

The front panel provides access to essential controls and displays operational status.

Figure 3: Detailed view of the Pro iDSD front panel, highlighting the input selector, filter knob, output mode switch, headphone outputs, gain control, and master volume knob.

• Power Button: Turns the unit on/off.
• Input Selector: Rotates through available inputs (USB, SPDIF, Optical, Ethernet, Micro SD). Press to adjust OLED brightness; hold to adjust polarity.
• Filter Selector: Cycles through digital filters and DSD remastering options.
• Output Mode Switch: Selects between Solid-State, Tube, or Tube+ amplification modes.
• Headphone Outputs: Includes 6.3mm (1/4"), 3.5mm TRS, and 4.4mm TRRS balanced jacks.
• Headphone Gain Selection: Adjusts gain (0dB/9dB/18dB) for various headphone sensitivities.
• Volume Control: Master volume knob for all outputs.
• OLED Display: Shows current input, sample rate, and selected filter/mode.

5. Rear Panel Connections

The rear panel houses all input and output connections for integrating the Pro iDSD into your audio system.

Figure 4: Rear panel connections of the Pro iDSD, including balanced XLR, RCA, Ethernet, USB Type A and B, digital inputs (Coaxial, Optical, AES/EBU, BNC), Micro SD slot, and power input.

• XLR Balanced Output: For connecting to balanced amplifiers or active speakers.
• RCA Single-Ended Output: For connecting to single-ended amplifiers or active speakers.
• Output Selector: Switches between HiFi Fixed, HiFi Variable, Pro Fixed, and Pro Variable output levels.
• Ethernet Port: For wired network streaming.
• USB Type A Host: Connect USB drives or external HDDs for direct playback.
• USB 3.0 Type B: Connect to a PC or laptop for USB audio input.
• Digital Coaxial S/PDIF Input: For digital audio sources.
• Micro SD Card Slot: For external storage playback.
• AES/EBU Digital Input: Professional digital audio input.
• WiFi Antenna Connector: Attach the provided antenna for wireless streaming.
• BNC Digital Input: Acts as both S/PDIF and AES3id.
• Clock Sync Mode: For external clock synchronization.
• BNC Sync Out: Clock synchronization output.
• DC Loop-out: For use with other iFi Pro series components.
• 15V/4A DC Power Input: Connect the iPower power supply here.

6. Initial Setup

1. Unpack: Carefully remove all components from the packaging.
2. Connect Antenna: Screw the WiFi antenna onto its connector on the rear panel.
3. Power Connection: Connect the iPower power supply to the 15V/4A DC input on the rear panel, then plug it into a wall outlet.
4. Audio Output: Connect the Pro iDSD to your amplifier or active speakers using either the XLR balanced outputs or RCA single-ended outputs. Select the appropriate 'Output Selector' mode (e.g., 'HiFi Variable' if using the Pro iDSD as a DAC/preamp).
5. Audio Input: Connect your desired audio source (e.g., PC via USB 3.0 Type B, network via Ethernet, or other digital sources).
6. Power On: Press the power button on the front panel. The OLED display will illuminate.

Figure 5: Example of a stacked iFi Pro system, illustrating rear panel connections for multiple units.

7. Operating Modes (Solid-State, Tube, Tube+)

The Pro iDSD offers three distinct amplification modes, allowing you to tailor the sound signature to your preference:

• Solid-State Mode: Provides a clean, transparent, and dynamic sound. This mode is ideal for critical listening and offers the most neutral presentation.
• Tube Mode: Engages the 2x GE5670 tubes, offering a warmer, more fluid, and natural sound with a slight emphasis on harmonic richness.
• Tube+ Mode: Further reduces negative feedback in the tube circuit, resulting in an even more pronounced tube sound with enhanced warmth and a relaxed presentation.

Switch between these modes using the dedicated switch on the front panel. Allow a few moments for the tubes to warm up when switching to Tube or Tube+ modes.

Figure 6: The GE5670 vacuum tubes, which are utilized in the Pro iDSD's Tube and Tube+ amplification modes.

8. Digital Filters and DSD Remastering

The Pro iDSD features several digital filters and DSD remastering options to fine-tune the audio output:

• Bitperfect: A non-oversampling mode that preserves the original digital signal without alteration.
• Bitperfect+: Applies an analog filter to correct very high-frequency roll-off present in Bitperfect mode.
• Gibbs Transient Optimised (GTO): A digital filter designed to minimize time-domain distortion with pre-ringing and minimal post-ringing.
• Apodising: Features no pre-ringing and modest post-ringing, offering a smooth sound.
• Transient Aligned: Utilizes a high tap count for precise transient response.

Additionally, the Pro iDSD can remaster non-DSD files to DSD512 or DSD1024, enhancing resolution. When upsampling to DSD512/1024, the unit first oversamples to 705.4/768kHz, and the specific digital filters mentioned above do not apply in these modes. Native DSD files are played in Bitperfect mode only, unless upsampled.

9. Network Streaming

The Pro iDSD supports wireless (WiFi) and wired (Ethernet) network streaming, allowing access to various online music services and local network storage.

• WiFi Connection: Attach the provided WiFi antenna. To connect, use the MUZO app (available for Android/iOS) or access the unit's IP address in a web browser after connecting via Ethernet. The WPS button (often combined with the filter button) can also be used for quick setup with compatible routers.
• Ethernet Connection: Connect an Ethernet cable from your router to the Pro iDSD's Ethernet port for a stable wired network connection.
• Supported Services: Stream from services like Tidal, Spotify, and Qobuz via the MUZO app. The unit also supports DLNA for streaming from network-attached storage (NAS) or media servers (e.g., JRiver Media Center) and AirPlay for Apple devices.
• USB Host Playback: Connect a USB drive or external HDD to the USB Type A host port. Content can be accessed via the MUZO app. Ensure media is formatted as FAT32.

10. Headphone Output

The Pro iDSD features a powerful balanced headphone amplifier capable of driving a wide range of headphones. It offers multiple output options:

• 6.3mm (1/4") Jack: Standard single-ended headphone output.
• 3.5mm TRS Jack: Single-ended output for portable headphones or IEMs.
• 4.4mm TRRS Balanced Jack: Balanced output for headphones with compatible balanced cables, offering enhanced power and channel separation.
• Gain Control: Use the gain switch (0dB/9dB/18dB) to match the output power to your headphones' sensitivity. Lower gain for sensitive IEMs, higher gain for demanding over-ear headphones.

Figure 7: The Pro iDSD connected to headphones, demonstrating its use as a high-fidelity headphone amplifier.

11. Troubleshooting

• No Sound:
  • Check all cable connections (power, input, output).
  • Ensure the correct input is selected on the front panel.
  • Verify the volume knob is turned up and not muted.
  • Confirm the output selector on the rear is set appropriately (e.g., 'HiFi Variable' for volume control).
• Static/Buzzing Noise:
  • If using WiFi, try disconnecting the antenna or switching to a wired Ethernet connection to rule out wireless interference.
  • Ensure all cables are securely connected and not damaged.
  • Check for ground loops in your audio system.
• Network Streaming Issues:
  • Ensure the WiFi antenna is properly attached and your network credentials are correct.
  • For DLNA, verify your media server is running and discoverable on the network.
  • If the app freezes with DSD files, try streaming lower resolution files or using a different playback method (e.g., USB from PC).
• OLED Display Not Working: Press the input selector button briefly to adjust brightness. If still unresponsive, power cycle the unit.
• Remote Control Not Working: Check battery. Ensure no obstructions between remote and unit.

12. Specifications

13. Maintenance

• Cleaning: Use a soft, dry, lint-free cloth to clean the exterior of the unit. Do not use abrasive cleaners, waxes, or solvents.
• Ventilation: Periodically check that the ventilation slots on the top and sides of the unit are clear of dust and debris.
• Tube Replacement: The GE5670 tubes have a finite lifespan. If you notice a degradation in sound quality in Tube or Tube+ modes, consult iFi support for information on tube replacement.
• Firmware Updates: iFi may release firmware updates to improve performance or add features. Check the official iFi website for the latest firmware and update instructions.

14. Warranty and Support

The iFi Pro iDSD 4.4mm comes with a limited warranty. Please refer to the warranty card included in your package for specific terms and conditions. For technical support, service, or warranty claims, please visit the official iFi website or contact their customer support directly. Keep your proof of purchase for warranty validation.

15. Product Overview Video