To all Mac users with the internal USB-DAC card installed:
Starting with Yosemite (Mac OS X 10.10) Apple requires all kernel extensions (i.e. your DAC driver) to be signed. Unfortunately, Lake People / Violectric have not updated their driver with the right signature yet. As a consequence the driver will not be loaded by the OS and your music will sound funny to say the least. If you already updated to Yosemite and have no way to roll back to the old OS version you can circumvent the problem by disabling the signature check with the following procedure:
- Open a terminal (open Spotlight and type "terminal", a text console will appear)
- Type the following: sudo nvram boot-args="kext-dev-mode=1"
- Press enter
- Type in your admin/root password and press enter.
The next time you plug in your Vio the driver should be correctly loaded (maybe reboot if not). You have to repeat this procedure after resetting the PRAM of the Mac.
PS: When you look around the internet you will notice that Violectric isn't the only company without up to date drivers. Apparantly a lot of USB DACs suffer from the same problem since the drivers are usually supplied by the chip manufacturers (Tenor in this case) who can't be bothered to sign their drivers. If you haven't updated to Yosemite yet I suggest you hold off until the situation has cleared.
Edited by nicooo - 11/19/14 at 8:09am