All versions of Spark support the following I/O device formats:
When using a version of Spark under Mac OS 9, you can use either Sound Manager or any I/O device with ASIO drivers. These include USB, Firewire and PCI I/O devices.
When using a version of Spark under Mac OS X, you can use any I/O device with Core Audio drivers, including the internal audio system. These also include USB, FireWire, PCI or PCIe I/O devices.