" ... At 10-15 hours, it was strange, sort of a roller
coaster of opening up and closing off, and me thinking there
was something wrong with it. Powered it off and back on
later in the day and it was open again, not as lean
..."
Question: Are you letting it (and all the components in your
system) fully warm up before you critically listen to it?
As an example. my REGA ISIS valve cdp and REGA OSIRIS
integrated amp both need a minimum of 2 to 3 hours to warm
up properly (particularly the tubes in the cdp) to sound
close to their best.
They sound best [ i.e. even better / "right" ] if
left on to warm up first for much longer periods before some
critical listening sessions.