I have not had the experience you report with my P300. Not sure this will help, but try plugging the BAT into the wall and only the digital components into the P300. I have found benefits from isolating your digital source components from the rest of the system. The BAT, I believe, has a well-designed and regulated power supply, so plugging it into the wall should not have a big effect on its sound, particularly if you have a reasonably good power cord for it. Good luck!
PS Audio PP300 works great, but......
Seasons greetings. I hooked up my brand new PP300 last night. If I listen critically and technically, I can clearly state that it does EVERYTHING they say it does. Much blacker background, Much tighter bass, Much greater detail and instrument space. However, even though all of these things are done better than I ever imagined, I find the music to be less involving. Has anybody else had this experience? Will it get better with break-in? I don't want to give up all of these benefits, but I want my musicality back. FYI: Sonic Frontiers T3/P3, BAT VK5i, BAT VK500, Dynaudio Confidence 5.