I bought the same unit on 12/16/2013, almost immediately after the first release. I loaded on the entire 1 TB with music. I did not use the unit for long time until the firmware upgrad so that I can use external DAC.
For your question #1: I had the exactly same issue. I have tried few power red USB hub with no success. Finally, I tried passive, no wire USB hub $2.99). It worked since then.
For your question #2: I am having the exactly same problem after the 2/28/2017 firmware update, prior to that, everything was prefect. After the update, I can not output PCM from USB output, no matter what I do. It will always output DSD with 512 with no sound, but noise. I have tried few DACs without success, one of my DACs shows 512, no sound but noise. All DACs failed play.
Analog (RCA) output plays fine. However, my DACs are lot better than Sony's DAC.
For your question #1: I had the exactly same issue. I have tried few power red USB hub with no success. Finally, I tried passive, no wire USB hub $2.99). It worked since then.
For your question #2: I am having the exactly same problem after the 2/28/2017 firmware update, prior to that, everything was prefect. After the update, I can not output PCM from USB output, no matter what I do. It will always output DSD with 512 with no sound, but noise. I have tried few DACs without success, one of my DACs shows 512, no sound but noise. All DACs failed play.
Analog (RCA) output plays fine. However, my DACs are lot better than Sony's DAC.