There appears to be an initialization issue between OS X Yosemite (has not been confirmed in Mavericks, but may exist) and the Geek Pulse if the Mac is in sleep mode for an extended period, and awakens.

This happens, even though the Pulse still appears as an Output device in Sound preferences.

To fix this issue, do the following:

- Go to System Preferences, Energy Saver

- Change Computer Sleep and Display Sleep to Never

- Uncheck “Put hard disks to sleep when possible”

Even though the computer cannot go to sleep automatically, you can still put it to sleep manually by going to the Apple menu and selecting Sleep. This will not cause any issues.