Notes: Since Mavericks, the Soft66lc SDR external has not been working in Max. Although I was not able to update the external, there is a temporary workaround.
Mac OS is hijacking the FTDI USB device with its own driver. You can unload the driver from terminal:
sudo kextunload -bundle com.apple.driver.AppleUSBFTDI
To reload the driver use “kextload”.
Here is article from Sparkfun with details about this workaround: https://learn.sparkfun.com/tutorials/how-to-install-ftdi-drivers/mac
And a more elaborate workaround that removes the Apple driver: http://www.mommosoft.com/blog/2014/10/24/ftdi-chip-and-os-x-10-10/
Notes about latency and FTDI http://openbci.com/forum/index.php?p=/discussion/199/latency-timer-os-x-new-info-plist
The real solution involves using the new Apple driver to communicate with the device: https://developer.apple.com/library/mac/technotes/tn2315/_index.html
Or spoofing the driver with a codeless kext: http://stackoverflow.com/questions/7263648/codeless-kext-loading-problem