Can an HDMI output be converted into something a USB input would accept?

Thanks Steve -- I tried that too, but no luck...

Thanks for the responses, folks -- I'm afraid this ship won't float.  @whart you may be right, but the Cambridge tech support people said it was a "DSD" signal, so I assumed they meant unencrypted DSD -- you know what happens when you assume.  It sounds like there is no simple conversion, so I'll just continue to listen to my SACD's the old fashioned way (which sounded good, it's just a bit inconvenient).  Happy listening to you all!