If the host is a VSTi system for OSX, it is possible that the VSTi version of the Bass Station has not been installed. The Bass Station was initially shipped as an Audio Unit Plug-in only. If an install disc only has the AU version of the Bass Station on the OSX partition, the full OSX VSTi version can be downloaded from the download section of this website. Once installed, use the serial number from the inside cover of the Bass Station manual to authorise the plug-in. If the VSTi version of the Bass Station is installed and the Bass Station still does not appear, particularly in OSX versions of Steinbergs Cubase SX, from the Devices menu within Cubase select 'Plug-in settings'. The Bass Station may be listed but not ticked. Tick the box to the left of the plug-in name, close the plug-in settings window, close Cubase and then reboot the Mac. The Bass Station should appear the next time Cubase is opened.