Advise please for best system upgrade under $2,000


I'd like to spend about $2,000 or less to update my system on either new or used components. What would you spend it on to get the most improvement? Speakers, CD, preamp, or amp?
I'm currently running all Solid State: Aragon 4004MKII amp, B&K Ref 20 preamp/processor, Sony DVP S7700 for CD and DVD (96khz/24bit D/A) and Magnepan 2.7 speakers. It sounds very good but I'd like to try tubes to get more musicality and depth. I mainly listen to Jazz and Rock(not Hard Rock).
Unfortunately, there aren't many high end dealers here in Indy so I'd probably be buying without auditioning.

Here's what I'm currently thinking:
1. Musical Fidelity X-Ray CD player($1,000) with a separate MF X-10 tube buffer attached($399).
2. ARC, CJ, Cary or other tube preamp ($2,000 or less used here on Audiogon).

Please offer your thoughts. Specific component and model recommendations are appreciated. Thanks.
noble100
Go with one of the tube pre's you have listed first. A new CD player or dac could still be had if you buy used. The ARC is probably the least tubey and you'll need to research exactly what you want. Some preamps with tubes actually sound syrupy and sloppy. I prefer ARC but tried a little Cary budget model and didn't care for the highs and lows. Beauty of it is if you buy here you can get most of your money back, maybe more if you don't care for it. You'll need to figure out for yourself what sounds best to you between the different tube pre's. It's a wonderful thing to learn about. As long as your Aragon amp still works fine I'd leave it alone. Personally I don't think there's much to be had without spending a ton of money for little gain in the amp department.
RealHiFi,
I'd like a universal player(SACD and DVD-A). Any suggestions on a model? Would a tubed output stage help or am I asking too much?

Mike,
I'm not using expensive cables. I'm embarrassed to say they're just Monster Cables. Do you think upgrading these would help significantly? Also, does the Marantz play SACD and DVD-A both?
I think the BAT's a good suggestion.
Thanks for both your help.
I would get a used Wadia 830 CD player for around 1500.00, you can run it direct to the amp with no preamp, and spend the other 500.00 on some decent cables.
You may consider room treatments and dedicated lines before any component upgrade as this will give you more than a component upgrade IMO. Happy Holidays
The most important component is the room. Spend your $2000 on treating the room and getting the acoustics correct. Add tube traps and RPG diffusers. This change will make a much bigger improvement than any component change.