Custom Firmware Builds for Element II, EL DAC II, and Atom DAC

We’ve mentioned the possibility of firmware updates for Element II, EL DAC II, and Atom DAC. Several custom options have been compiled by now, so below is a list of all releases we have shared thus far.

Feel free to comment if you are interested in something unique!

Features currently in evaluation at the time of writing include:

  • DoP: Support for DSD over PCM means the USB device can receive DSD and transmit to the DAC as a PCM I2S stream. Native DSD is supported by Element II and EL DAC II hardware, and may be available with future drivers.
  • OS Volume Controls: Also called “Hardware Volume”, this option prevents your operating system’s volume slider from adjusting volume. Most customers find this option unhelpful, so we have elected to keep OS volume controls enabled by default in all production DACs. Certain use cases necessitate disabling volume controls (mainly for PS4 owners).
  • UAC2 / UAC1: Element II, EL DAC II, and Atom DAC are intended to take advantage of USB Audio Class 2 drivers for up to 32/384kHz support and optional ASIO usage. Older operating systems and PS4s only provide USB Audio Class 1 drivers, which limit sampling rate to 24/96kHz max. Please keep in mind that installing a UAC1 firmware disables UAC2 support and removes the ability to install firmware updates on the DAC, meaning installing UAC1 firmware is a one-way street. Any firmware built for UAC1 will be listed with a warning note.
  • Self-Power: All current JDS Labs DACs are designed to use their own AC power adapter. Nevertheless, some operating systems default to confusing power management settings for USB devices declared as Self-Powered. For this reason, we programmed Element II, EL DAC II, and Atom DAC to boot by default without the self-power flag. This choice is meant to simplify setup with Win10 and MacOS. For iOS, lack of the self-power flag means that a USB hub is required so that the phone or tablet’s battery is not utilized. Enabling the self-power flag eliminates the need for a USB hub to establish a UAC2 connection. Connection with Win10 is supported with the self-power bit, although you may need to disable USB Selective Suspend.

Firmware versions highlighted in bold are the default you should expect if ordering today. If you prefer an alternative configuration, you are welcome to describe your version request in the Shipping Notes field during checkout and we will load onto your DAC before shipment.

Element II

Version DoP? OS Volume Controls? UAC2 UAC1 iOS Connectivity? Note
1.3.3 No Enabled Yes No Requires Hub Initial release
1.3.4 No Enabled Yes No Requires Hub Updated USB device name JDS Labs Element II
1.3.5 Yes Enabled Yes No Requires Hub Added DoP
1.3.6 No Disabled Yes No Requires Hub Lock output volume to 100%
1.3.7 No Disabled No Yes Requires Hub Supports PS4; WARNING: Disables Future Updates!
1.3.8 No Enabled Yes No No hub required See Self-Power section



Version DoP? OS Volume Controls? UAC2 UAC1 iOS Connectivity? Note
1.6.3 Yes Enabled Yes No Requires Hub Initial Release
1.6.4 Yes Enabled Yes No No hub required See Self-Power Section


Atom DAC

Version DoP? OS Volume Controls? UAC2 UAC1 iOS Connectivity? Note
1.4.2 No Enabled Yes No Requires hub Initial Release
1.4.3 No Enabled Yes No No hub required See Self-Power Section
1.4.4 No Disabled No Yes No hub required Supports PS4; WARNING: Disables Future Updates!
1.5.2 No Enabled Yes No Requires hub Disables  Standby Mode; see Self-power Section



You may install any version of firmware for your DAC; there is no need to install versions sequentially. Version numbers are used for identification purposes only.

We strongly encourage updating through the XMOS DFU app for Windows 10. Installing in MacOS is supported by the XMOS DFU loader, which is a command line tool.

In Windows 10

  1. Begin by installing the XMOS Drivers for your DAC if you have not done so already. Drivers can be found on the product page, or from our general Downloads page.
  2. Connect your DAC directly to a USB port on your computer. Connecting through a USB hub or USB port on your monitor can prevent the update app from establishing a connection.
  3. Open the DFU update app, which is found in the directory where you installed the XMOS drivers, by default in Windows 10:
    Element II 
    C:\Program Files\XMOS\USBAudioStDriver_30DA\W10_x64\xmosusbaudiost30DA_dfuapp.exe

    EL DAC  II
    C:\Program Files\XMOS\USBAudioStDriver_30E0\W10_x64\xmosusbaudiost30E0_dfuapp.exe
    Atom DAC
    C:\Program Files\XMOS\USBAudioStDriver_30E1\W10_x64\xmosusbaudiost30E1_dfuapp.exe
  4. Download a new firmware .bin file from the list above.
  5. Click Browse and select the downloaded .bin file.
  6. Start Start. You should see the version number change upon completion.

In MacOS

Please see page 8 of “Using the DFU loader – OS X”. You will need to install the XMOS DFU compiler as described here. You may need the following VID/PID numbers for the command line tool:

VID: 0x20B1
PID for Element II : 0x30DA
PID for EL DAC II : 0x30E0
PID for Atom DAC : 0x30E1


9 thoughts to “Custom Firmware Builds for Element II, EL DAC II, and Atom DAC”

  1. I am looking to buy an Atom stack. I must be able to use the Atom DAC with both Win10 and iOS (13.7 now and 14 when available). You mention the need for a USB hub for iOS connectivity. Will use of the Apple lightning to USB 3 camera adapter fulfill the hub requirement for iOS? If not, please specify what adapters or workarounds are necessary for DAC operation with both these operating systems.

    1. @InMotian – Yes, you may use Atom DAC with the Lightning adapter and a USB hub as described at

      I’ll upload an alternative firmware shortly which should bypass the need for a hub.
      Edit: See v1.4.3

  2. My Element II is connected directly to my iPad Pro with the Apple USB-C Multiport Adapter and it works fine without an additional hub. Is the Multiport Adapter serving as a hub in this scenario? Is there any disadvantage with this setup, and would I see some advantage installing 1.3.8?

    1. @Alan – Yes, some of Apple’s adapters avoid the need for a hub. There’s no advantage to installing v1.3.8 in this case.

  3. Element II version 1.3.5 appreciated. DoP matters most to me. #2 need after that is 4.4mm balanced output. Guessing I won’t see that from JDS anytime soon?

    1. Thanks, Brian. We’re currently reworking DoP support for EL DAC II and Element II, and once we’re content with the beta firmware it will become standard.

      As for balanced headphone connectivity: We view 4.4mm balanced connectors as a marketing fad in direct objection to our performance standards. Benchmark explains well in their article titled AUDIO MYTH – BALANCED HEADPHONE AMPLIFIERS ARE BETTER

  4. Just thought I’d mention that I got this to work under Mac OS Catalina. I have no experience building source code, so it was a little slow going. Before building, I installed X-Code and the X-Code command line tools from Apple, installed Homebrew and the latest USB libraries via Homebrew, then edited the xmosdfu.cpp file to replace the VID and PID codes with the ones mentioned in this blog post.

    These instructions were the most understandable for my beginner’s brain:

    Note that the instructions don’t cover editing the xmosdfu.cpp file for different vendors and devices. I edited the relevant section of that file so that it looked like this:

    /* the device’s vendor and product id */
    #define XMOS_VID 0x20B1
    #define XMOS_L1_AUDIO2_PID 0x30DA
    #define XMOS_L1_AUDIO1_PID 0x30E0
    #define XMOS_L2_AUDIO2_PID 0x30E1
    #define XMOS_SU1_AUDIO2_PID 0x0008

    I successfully changed the firmware on an EL DAC II from 1.6.3 to 1.6.4.

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