Symphony 64 features Extended Audio Routing with VBus and SBus technology. VBus allows users to route demanding, stand-alone software instruments, directly between Core Audio based applications, instead of running them as plug-ins. Symphony’s SBus doubles the DSP power of The Symphony System by facilitating the communication of digital audio between Symphony equipped Macs with a single cable. Now it is possible to route audio to a second computer and back again for plug-in processing, sample libraries, soft-synth players, and session transfers from one Core Audio application to another.

As with all Symphony PCI/PCIe cards, this is only half of the system. A full Symphony system requires an X-Symphony card be installed in each Apogee converter. The Symphony 64 is available by itself to upgrade/expand an existing Symphony system or bundled together with up to 4 X-Symphony cards.