Incremental improvements

I am looking for suggestions on how to make incremental improvements in my system at reasonable costs.

Here is my system:

Rotel RCD-965BX player feeding an MSB Link 2 via an MSB cable.

Home-made Cardas Twinlink cables into an Aronov LS-9000 preamp with 1950's vintage Mullard 12AX7 tubes.

Home-made Kimber PBJ feeding a Classe 10 amp.

Entry level Kimber shotgun biwire cables feeding North Creek Music Borealis speakers.

I use all stock power cords and I use not power conditioning.

The room is fairly small (13 X 15) and I listen to jazz, pop and rock.....i.e James Taylor, Jennifer Warnes, Mary Black, Pat Coil, FourPlay...etc.

At this point the system is really pretty nice (at least to me), and some of the short falls that I hear are probably shortfalls in the recording, not the system.

I would like to warm up the sound just a bit if possible, add more extension and refinement to the sound and perhaps a little more "air" around voices and instruments.

My sense is that my best opportunities are with my digital front end and cableing.

I have been kicking around van den hul First Ultimate interconects as well as interconnects and speaker cable by Signal Cable and Cardas, and speaker cable by Speltz, DH Labs, and Kimber (8TC).

I have also thought about building an Audio Note tubed DAC or buying a new CD player.

I have really enjoyed AGon since I discovered it several moths ago. I would really appreciate input from you on where my best opportunities are in making cost-effective improvements.

Thanks for your time.
Try a PS Audio Ultimate Outlet-plug your CD player & MSB dac into it-you will notice a drastic change.
New $300-Used $150 to $200 or do a home trial with the Cable Company or PS Audio.
Tweaks. Power, Resonance Control, and Acoustics. One place I might start is the Mapleshade Ionoclast gun. Zap all of your CDs and cables. You should notice increased clarity and retrieval of low-level musical information. Then get some Walker SST, paint all of your contacts, including AC power. Burn it in for 5 hours minimum. Then get some Mapleshade heavyfoot brass cone footers. Also place a few upside down on top of your transformers.

You might also try experiementing with slightly different speaker positioning as well as listening chair location. That can help change the sound, and it's free just given some time and effort on your part. Toe-in/toe-out changes the treble balance, "air," imaging, focus, etc. And closer/farther from the back wall changes bass balance. Also moving your listening chair out a few more feet into the room can likewise change the tonal balance and imaging focus for the better.

Let me throw in my 2 cents here. I recently changed my ICs to Ridge Street Audio Poiema Sig, (and I'm using SS gear), this was a very revealing change (see post in reviews). Now I have been guided by a Very estute teacher in helping me gain tremondous gains in performance and jaw dropping results, and here is the name... Bright Star Audio. With just a change in the ICs (NO small change at all either) and the addition of BSA Air Mass and now Big Rock 3 detail, speed, attack, decay, oodles of detail and layering to die for. Isolation is critical in digital and I am without doubt of this now becuse these changes take you where needed and if your budgeting (like I have to) I've just saved bushell baskets of money from NOT CHANGING EQUIPMENT.
hope this helps some