How to add depth for classical music

While listening to classical music, especially the orchestral pieces (e.g. Beethoven Piano/Violin Concertos, Symphonies), I find that my system is not giving me the depth, such as layers of instruments etc.   My listening environment is not ideal.  I have hard wood floor and tray ceiling.  On one side, I have windows and on the other side, I have a long corridor.  

Here's my system:

• Parasound P5 & A23
  
• Sonus Faber Venere 3.0
  
• Bluesound Node2i
  
• Chord Qutest
  

Would a new preamp/amp or integrated amp help?   I've auditioned Moon (SimAudio) 340iX and thought it's more opened than my Parasound.   But for some strange reason, I didn't really like the sound.   Maybe I need to audition again.  

Would room treatment help?  But my options are limited because of my room.

Love to hear your thoughts.