What's next for the ultimate sound quality?

Gleb, great job on the speaks! You definitely need some better amplification to get them to shine. IMO there aren't any mass market "receivers" out there that can beat a decent integrated or preamp/amp combo - just my opininon.

Tubes certainly aren't just audiophile fluff. Generally, they impart a bit of richness and depth in a system (among other qualities). I am currently using a Jolida 502BRC tube integrated and might not ever go back to SS. For the money it beats any SS I have ever used. What is the speakers sensitivity rating?

Looking at your room I would strongly suggest room treatments. Start with a thick area rug (preferably padded underneath) between your listening position and the speakers. Next, get some absorption at the ceiling and wall first reflection points. There is plenty of info on the web about this. I did this a few weeks ago and am enjoying the vast improvement.

Finally neighbor, you are lucky to be in a big city with a wealth of audio shops. Get out and start some auditioning ASAP! Most places will let you home audition gear. Search the archives for shops in Chicago or let me know if you need assistance.

Right. So the consensus seems to be to leave the speakers be and upgrade amplification + install sound panels.

If tube amplifiers sound as cool as they look, then I'm sold :) It also seems possible to build one yourself and stick to the DIY philosophy. I'm afraid the richness of sound also means "warmness", no? In this case, tube amps may not be the best match for the warm scanspeak drivers. I'm going to try a tube amp anyway. Also, browsing a little online about Krell 400xi, it seems that it's kind of bright, revealing and aggressive, which is exactly what these drivers need imho. Definitely something to try!

So many thanks, everybody!

The system sensitivity is around 92-93db. The tweeter is 92.5 and woofer is 87, but since there are 2 of them wired in parallel facing the same direction, you get +6db = 93db for the woofers as well.

You describe two shortfalls: soundstage and imaging and thin sound.

The soundstage and imaging could be improved with the acoustical treatment as suggested by Mdowns32. You are probably getting alot of sound reflection which blurs the image and soundstage. Also, make sure that the speakers are equi-distant from side and back walls. Also, play with toe-in angle.

Thin sound: You might try putting the speakers closer to the corners or at least closer to the back wall.

Other than that, you are into trying a number of things including different amplification - I have always preferred tube and there are a number of different designs using different driver tubes that can affect the sound. I have gotten the impression from reviews on digital switching amplification is that it can sound thin. You might want to try different cables. Good power cables can make a huge difference. The DAC recommendation is also very valid. Finally, controlling vibration and resonance is also important.

My suggestion would be try to locate the closest audio society in your area, listen to different set-ups, and possibly borrow equipment from other members to see what the effect is of different equipment, cables, etc.

You will get a lot of good recommendations from the Audiogon forum but it comes down to gaining experience with different types of equipment - solid state, tube, and digital switching amplification; effects of cables, effects of good transports, effects of vibration control, and so on...

Good luck and enjoy the journey!

If you go with a kit for amplification, check out the Audio Note kits.