Symphony I/O (Mk1) Release v5.5: Notes and Comments

What's New in this Release:

  • Support for the following on macOS Big Sur on Intel and Apple Silicon Macs
      • Symphony I/O (original Mk1)
      • Symphony64 PCIe card
      • Symphony64|Thunderbridge
      • Legacy interface support with Symphony64 PCIe or Thunderbridge: AD16x, DA16x, Rosetta 800, Rosetta 200
  • System Requirements: macOS 11 or later - Apple Silicon and Intel Processors

*This installer is not compatible with macOS 10.15 or lower. User previous Release installers for older macOS versions.


If you’re using an Apple Silicon Mac, you will need to allow user management of kernel extensions to install the Apogee driver.

  1. Quit this installer and shutdown the Mac.
  2. Press and hold the Mac’s Power button until the display shows Loading Startup Options, then release it. This takes you to the Startup Options screen.
  3. In the Startup Options screen, select the Options icon, then click Continue underneath it.
  4. Once the main window has loaded, select the Startup Security Utility in the Utilities menu. You’ll then be prompted to select the system for which you want to configure startup security. Once you’ve unlocked that disk, click on the button to set startup security for that disk. Then select Reduced Security, and check the upper of the two boxes, which allows user management of kernel extensions.
  5. Quit Startup Security Utility, and select Restart from the Apple menu to restart into normal mode.
  6. Once you’ve restarted, launch this installer again and begin the install. Towards the end of the install, before you restart the Mac, open System Preferences and go to the General tab of

    the Security & Privacy pane. If you see a message towards the bottom of the window with an Allow button, then unlock the Security & Privacy pane and click the Allow button. If the Apogee installer has finished, restart the Mac.

Note on Firmware

  • Nothing has been changed since the previous Symphony Release, other than support for macOS 11.0 and Apple M1. If your Symphony I/O is already on the latest firmware, there is no firmware update required. If your Symphony I/O is using older firmware, you will need to download the Symphony I/O Firmware Updater from the previous Release 5.4c Installer package and use an Intel Mac running macOS 10.10.5 or earlier (10.6.8 - 10.9 recommended) with USB 2.0 ports to update the firmware, as the firmware updater app is not compatible with any version of macOS newer than 10.10.5.

Known Issues

  1. I/O level controls for Symphony I/O do not work from Audio MIDI Setup, System Preferences Sound, or the Keyboard Volume Control.
  2. Clock Source menu no longer available in Audio MIDI Setup.
  3. GUI graphical anomalies in Maestro 2 software