My DAC has been running for 4 weeks and it now getting very good. Both DAC chips have broken in so please disregard the above post as it has no meaning.
This is a great DAC now that it has lots of hours on it. I have sold the Berkeley Alpha USB converter running into the AMR 777. The AMR 777 has a better USB input than the Berkeley running through the BNC connector. When running the Berkeley into the AMR777s BNC connector the sound loses punch which is not a problem using the internal USB connector. So I am quite happy with the AMR777 DAC now.
I am using an Audioquest Diamond USB cable. What USB cables are you guys using with the AMR777 DAC?