Need advice on overall system

Jax2 is right about speaker placement. Are they on stands? Are they isolated from the stands or bonded to them? Try angling them inward so the axis of the tweeters cross just ahead of you're listening position. Playing around with speaker placement is one of the most critical improvements you can make to a system. It is also cheap. Check the distance to side and back walls.

I'm not that familiar with your specific components so I will limit my comments to general ones. Although cabling and power conditioning can certainly make a difference, those differences are more about fine tuning. If you are unhappy with the overall performance/sound of your system, a change in cables or conditioning is not likely to make a leap that would overcome that kind of dissatisfaction IMO. I do think your suggestion about the room could have more impact, but not knowing how bad it is, that would be hard to say. Treatments can be as wife-friendly as carpets, wall coverings and plants in the right places. Speaker positioning also can have a pretty significant impact on presentation. Have you tried playing with that? Just looking at the list of your components my knee-jerk reaction is that if I were to work on one of them it would be the preamp. Seems like the others are proven performers at the top of their class, whereas the pre is a DIY unit that seems a bit outclassed by your other components. The preamp is a very important part of the chain so I might start there. Again, that is just a gut reaction - I have no direct experience with any of your components.

Marco

Tweak- You're right, I do tend to confer less importance on those things. I have anti cables and ICs, but no power conditioning or after market power cords. I never thought of them as basics and think it's more important to put the money into components. Obviously, I could be wrong.

If the majority of you think my components are even adequate, I would really appreciate suggestions on better cables and conditioning. Also, I have no room conditioning, but that's more of a wife thing. I can't afford to spend that much on such things- Audio Magic products have been recommended many times, but they're out of my price range.

You neglected to mention the basics- power conditioning, and cable choices.

Leads me to think you are unfamiliar with what they can do