Replace Amp or Preamp?

First let me start by saying that im very satisfied with my budget system which currently consist of:
Electron Kinetics Eagle 400 mono blocks
Mcintosh CR10 zone control preamp
Theata data basic/Theata data universal 3 transport
Dunlavy SC4 speakers

I do notice that on some difficult passages I get a little jumble in the music not enough to make me disatisfied but I do notice it from time to time. I have been told by some that the weak point is the CR10 seeing how it is not a true preamp but more of a zone controler. Ive had one person blame it my amps saying that they were good bass amps but thats about all. To each his own but I love the amps as I find them warm and musical.
I have looked at couple preamps but not sure what direction to go thus far im looking at the following:

Audio Experience Symphonies tube preamp
Theata Theta Casablanca

Ive looked at several older Mac preamps but can not bring my self to pay more for a piece of equipment than it cost brand new.

Any suggetions on the 2 preamps mentioned above would be great or any others in the $300 to $500 range that are currently avaliable would be great. For those that think I should be looking at amps as the weak point what do you think of the emotiva XPA-1 amps or any recomendations in the $1000 range?

Your digital front end is several generations behind the times, You might try to borrow a newer DAC and, for purposes of getting a handle on the preamp position, try one with decent integrated volume control. A Benchmark, for example.
Drubin both Data's are just transports. I forgot the name of my DAC as I put this post together. I will look when I get home and add it to this post.
Your Pre-amp is definatley the weak link. I owned the MAC CR10 and it is average at best. I like your suggestion of the tubed pre or maybe try and find a NAD C162 which is an excellent pre-amp for the money. (maybe $350 used?)
Mik971 thanks for the input! Here in Columbus Ohio all the audio shops have closed their doors. So no more trying diffrent gear in your rig it's all internet driven so you have to buy then try and resale if that piece dosent go with your gear or you dont like the gear!
If your amps seem to drive your speakers well, pick up a used pre-amp on A-Gon. That way you can sell if for some reason it is not a good match and not loose much. I think it will be pretty easy and you will be thrilled with the results. Again, the McIntosh works well for a switcher, but not as a pre. The difference will be dramatic and be money well spent. If you listen to mainly digital sources, get a tubed pre if you can afford. It is a great way to try tubes with very little technical skill needed.
I agree, I had a McIntosh c15 which was decent but then I paired a McCormack RLD 1 with my McCormack DNA 125 and it was night and day.

Fast forward five years....I wanted to upgrade and couldn't decide where to start. I had used the DNA 125 with a few preamps and decided that it is a great amp and maybe the best improvement was a preamp upgrade. It is such a good amp that I think it would take a lot of $$$ to better it.

Don't get me wrong the RLD 1 is a very good pre but I took a chance and brought home a conrad-johnson Classic 2SE. I was giving up a lot, no remote volume or source selection, no balance (never used it) HT loop, etc. but at the end of the day sound quality is paramount. The c-j made such a pronounced improvement I ultimately upgraded my speakers and dac... I have never listened to so much music both old and new since getting that pre. It was the best purchase I've made in a long time. I am not listening to analyze or critique my system, I'm just enjoying the awesome sound and synergy these components have together.
I think your preamp is definitely the weak link here. The problem is a good active preamp isn't cheap and I think it will be difficult to get one within your budget. (Understand, that's just my personal opinion. Also, difficult is not impossible. Sometimes good deals do come along.) You may want to consider a passive unit. You can easily find something well within your budget and the sound quality is usually far better than a cheap active preamp. Creek and Channel Island both make passives that should work well for you.
Mik971 the monoblock amps drive the Dunlavy's very well and easy. Anyone have any thoughts on any preamps currently on audiogon? I've been looking at a Proceed pre preamp and the two I mentioned above. Or any others on Audiogon?
I like the Quicksilver at that price. Lp Gear has a demo for sale at $900. Can be had used around $600 from time to time. I used one with a Carver amp, and liked it a lot.
A used Quicksilver would be excellent and a major step up to higher level musicality and natural sound. They are very well built and exceptionally reliable. Good call Acman3.
A few years ago I owned the Proceed Pre you ask about and was not impressed with it. Can't recall much about it other than being unimpressed.
There are not a lot of preamps listed in your price range, and none of the SS pres in the <$500 range look interesting. There are a couple of tube pres that are interesting though. The Decware preamp listed looks good and is located in Columbus. You might be able to listen to it before purchasing. The other tubed pre under $500 is the Dared. It has been favorably reviewed. Either of these pres are worth investigating to make sure they are compatible with your amp.
I have no experience with any of your gear so take this FWIW.
Any one have any experience with the Audio Research preamps. The LS1 or LS7?
I agree iwth Mik971
I also owned the AR LS1 tube hybrid pre-amp. It is an excellent sounding unit!! It did not work in my listening area because it had a stepped volume control so I couldn't dial in the exact volume i wanted. (amp didn't match perfectly) I think you would be very happy with the AR or possibly a used Conrad Johnson if you can spend a little more..
Mik971 AR LS1 or Motif mc9 by Conrad Johnson? If you had to pick one.
Tough choice. I am familiar with the ARC unit and it is excellent. I have only heard the Conrad Johnson PV3, PV10 which are both excellent. I would stick with a tubed/tube hybrid pre if it were my choice. The Motif line of pre-amps have good feedback online, but are solid state so you can't fine-tune the sound with tube rolling. Either way you won't go wrong as it will be a large improvement over the McIntosh.
Seems everyone leans towards a tubed/tube hybrid with SS amps or digital fronts. This will be a new venture for me. One that I've been contemplating for some time now. So I guess it's time to take the plunge!