That's what I'm wondering. The site seems to mention compatability with only firewire/USB DACs.
EDIT: From the website:
Q: What hardware will work with Amarra?
A: Amarra works with most FireWire and USB DACs. To ensure full functionality Amarra has been qualified to work with these audio interfaces:
• Amarra Model Four and Model Three
• All Sonic Studio Audio Interfaces (302/303/304/305)
• Benchmark
• Empirical Audio
• Lynx AES16e PCIe (Mac Pro)
• RME Fireface 400 and 800,
• Sonicweld Decoder and Diverter
• Wavelength
• Weiss Engineering Vesta, Minerva, AFI1, ADC2, DAC2
• More interfaces are qualified each week.