The headphone amplifier is wonderful. The documentation for the product is in need of serious attention. The DAC interfaces and USB input have absolutely no usable information. How about some instructions and decent explanations on which driver to select and installation specifics? I had my Cambridge CXN up and running in less than 30 minutes. After more than 6 hours of searching through obscure Internet sites and e-mailing one of the posters, I think I have it running correctly through the USB input, be I’m really not sure. Seriously, if you need to have a customer review the documentation or test your processes and procedures, I’d be happy to help. Nothing ruins the buying experience like not being able to use what you bought.