Thank you for the awesome response. I am glad that you are enjoying all of your Audio-GD gear. I did a lot of research before making the decision to invest in Audio-GD. I have owned iFi, McIntosh, Mytek, and now the Topping DAC, and wanted a DAC that can be upgraded and is customizable.
I asked about the USB Blaster because I see here where people are downloading various firmware versions to try on their DACs. It sounds like there is a lot to discover with the factory firmware that will be installed on the R8. I think I will try it "as-is" with the existing setup before trying different firmware. It is good to know that that is an option. For your source settings, are those available from the front panel buttons?