I have those wonderful transparent Harman Kardon speakers attached to an iMac. I'd love to use a ConnectAmp to play music through these speakers. They need to be attached to the Mac USB port. I've tried attaching the 2 small speakers directly to the Connect in order to use them simply as speakers, but that doesn't seem to work. Using the Mac as line in doesn’t work either even though a computer is listed among the possible line-in connections. Any ideas other than buying new speakers?