Which makes the bigger difference?

Agree with Krysgel, your question is about which change in electronics will get finer detail resolution, and isn't about changing speaker or room. Looking at your system as listed I think I would look at a CDP upgrade.

Sorry also failed to mention my interest in the Bryston CDP1 and the Sim Equnoix SE as a possibile match up as well

Thanks to everyone for thier thoughts, I pay ALOT of ATTENTION to vibration control and Room Tuning has made huge differences, as well as other small things such as great cables, cable elevators and PS Noise Harvesters. I've got a small room so little adjustments produce (sometimes) profound differences. Just wondering about my gear, I'd like to go to an ARC CD3 or maybe a Jeff Rowland Integrated (if I can muster the funds) but that's why I ask the question of impact and from what might the best logical choice if I were to make a change and if to go to seperates.

Given your speaker setup is as good as possible... and so forth... the biggest improvement in sound staging, and imaging results for me came by way of going to mono blocks. Tube or SS. First was SS twin mono's on one chassis. Super. that was followed by actual separate twin mono block tube amps. Better in many ways, but they don't match the presence the big dual mono stereo SS amp provided.

Each instance was channeled thru one of two tube preamps in SE fashion. Although the tube monos don't provide the immediacy of the SS amps, nor the bass impact, I do enjoy them equally well... and I am continually torn between the two distinctly different sounds each presents.

the best situation? having both tuype amps is clearly the way for me... and just switching back and forth from time to time as the mood indicates.

having both available, I am not intrigued sufficiently to bi amp my speakers with them either.

gotta agree with the speaker-room guys

My experience is that anything that obscures low level detail will reduce soundstaging. After all, it is the low level detail that creates the soundstaging effect. All components in a system will obscure detail to some extent, so more revealing gear all around will improve soundstaging.

Another crucial aspect is vibration control. If you are using the stock rubber feet that come on most gear, this will obscure low level detail. Switching to cones and other such footers will make a big difference.

I would look into Audio Research tube pre and SS Amp combo. See if anyone else with Apogee speakers are using AR gear.

Agree with Michael.

For soundstaging, I think the most important components are the speakers and the room, and the positioning of speakers within the room. Next is probably the amplification (preamp + amp), and the associated SS vs tubes differences. The CDP will also play a role, but I cannot say to what extent compared to preamp + amp.

What is it that you don't like about your current situation?

I would advise trying to optimize the position of the speakers first, then consider some cost-effective room treatments, before blinding going about changing components.

Just my 2 cents.

Michael