Help. System sounds thin and bright or harsh

Lots of thoughts.  I don’t think your equipment including the DAC is terribly warm.  That said, it is not like you have obnoxiously bright stuff either.  
 

Thinness can come from a few places.  Tell us more about the room.  Carpeting?  Wall treatment?  Pictures, windows, curtains, etc…. How far do you sit from the speakers?  
 

Do you have a subwoofer?  Those start rolling off above 50hz and it is going to sound thin at lower volumes.  A good sub could help that out potentially.  That along could be your issue with fullness.  Regarding edginess, That could be a single component.  Might be the JC2, might be the pass.  I have a Modwright UDP 205 here paired with AGD amp and preamp and it is sweet and musical.  
 

I would  try a sub.  Let’s here more about your room but you might borrow an amp or preamp from your retailer that you work with to see if it helps.  

My first thoughts all centered around positioning. But it sounds like you have covered that. Secondly floor and wall treatments. It would be really helpful to us if you could upload photos of your system and venue to virtual systems under your UserID. Often, one look can completely redirect the discussion to some relavent factor. 

I have owned lots of Pass gear and the line that sounds more in line with your interests would be the XA line. They are much warmer and more natural. Tubes… everywhere and anywhere are appropriate.

Parasound preamps are not known to be particularly trebly or hot on the top… but a good tube preamp will definitely more to your liking… maybe used Audio Reseach or Conrad Johnson… Rouge can be a bit hot for tube gear.

"Harsh" can be a result of out of spec distortion in any of the front end components. To rule that out you'll have to swap out each piece one at a time. If it solves the problem, then the offending piece can be sent for testing/service.

in your old room was your back up against a wall and now you are sitting out in the room?  

sitting up against a wall reinforces bass quite a bit.  

is the new room more lively / less furnished / less treated with drapes and carpet?  

also settings can change when gear is moved around.  could you be using the inverted polarity outputs on your preamp or one of them?  

Apart from a pair of REL T5x, I'd look at the tubes. Any idea what 6SN7s are fitted?  RCA VT231 or Ken-Rad 6SN7 are on the warmer side.