dBpoweramp is currently in beta test for OS X:

http://forum.dbpoweramp.com/showthre...-Apple-OS-X-R1

The expected release date is early January 2015. dBpoweramp OS X will be on a separate license to existing dBpoweramp Windows, we will offer a 50% discount on purchase of dBpoweramp OS X for existing users of dBpoweramp R15 Windows.