A deeper more holographic soundstage.

As three_easy_payments said tube rolling has improved this for me. A recent acquisition of Sophia Electric KT88 tubes has really changed the sound stage for the better and yes, proper speaker placement is a must.

In order of importance: Loudspeaker. Loudspeaker position. Room acoustics. Pre-amp/amp. Source. 

In order of importance: Loudspeaker. Loudspeaker position. Room acoustics. Pre-amp/amp. Source.  Other miscellaneous tweaks.

roxy1927

Here what I said to another member, and his reply a few weeks later, after he did what I said.

"Equipment between the speakers is the single biggest killer of sound staging and depth perspective, it makes a hiend sound into midfi, because there’s no artist to place and see with your eyes. 
If you can’t go to the side, maybe the behind you, or as I did in one place that allowed it, the next room."

hiendmmoe OP
First and foremost to say it didn’t make huge difference would be the understatement of this century. I think I solved most of issues regarding everything. The two biggest improvements: spacial depth and much lower noise floor. Everything sounds so much more open. I’ll never place my rack between my speakers again!

Hallelujah!!!
Now we just need to convince the other 80% of "glitz queens" who would rather stare in wonderment at their lit up electronics and shiny machined racks, instead of seeing the imaging, depth and sound staging placement of the artists of the music they play.

It never ceases to amaze me with "glitz queens" at the money they spend just to look at their equipment while listening, and they really do stare at it, maybe trying to find the image/depth between the shiny machined boxes, instead of basking in it.

Cheers George