Amp shopping - recommendations anyone?

Hello all. I'm thinking of treating my system to an amplifier upgrade, and would really appreciate some advice. Here's my situation.

Currently running:

Aragon 4004 Mk II
Aragon 24k Preamp
Rega Planet CD
PSB Stratus Gold i Speakers
Kimber cable throughout

I'm very happy with my PSB's and my Rega and don't plan on changing those any time soon. I'll probably tackle the preamp and cabling sometime down the road.

Things I'd like to improve in my system's sound:

- Currently a bit on the warm side
- Bass could be a little tighter
- Would like it to be "faster" (want Linn timing with PSB headroom)
- Soundstaging could be a bit better defined

I'm budgeting approximately $2,700 for the amp upgrade and am strongly leaning towards used. Contenders would include:

- Krell KSA 250
- Classe 301
- Pass Labs X250
- Bryston 7B ST
- Others?

Looking forward to any feedback or advice.

Frankly, I'd go for Musical Fidelity amp/preamp the 3.2 series. The two will cost you about what you want to spend on the amp alone, and you can put the rest of your money into music. I've had far more expensive equipment so I can tell you that Musical Fidelity is worth several times its price. Although I don't take Stereophile as graven in stone, both units are the only inexpensive items to be on their "A" list. Just an opinion. Regards.
InnerSound ESL amp meets your requirements. 30 day trial, plenty of power, nice open highs, used in the $1500 range.
Have you considered the Aragon Palladiums...definately in your price range...they are a tremendous step above the 4004 I have had almost every aragon amp in the last 2 years..
The palladiums are by far the best monos I have had and simply better in every way than the 8002 for 2 channel and the 4004.
My second choice on your list would be the Krell
followed by the Classe...
Best of luck
Custom Audio LLC
I hope you plan on upgrading both the preamp and power amplifier.
There are a ton of amps out there and some may add a little of this and a little of that but IMHO you get a bigger improvement with a better CDP and speakers. I tried over 12 amps last year and I now realize that my system was more limited by the other components than the amp.
Gamut D200 MkII used.
CJ Premier 12 used (there's one here now).
It sounds to me as if you are describing the exact sound characteristics of PSB Stratus Gold i's. Not saying they are inferior speakers by any stretch but that is just the way they sound. I would try and demo as many amps as possible with your speakers. And as far as your aragon amp is concerned i have found that a tubed preamp is a far better match than an ss pre.

Just my 2 cents.
Both the Levinson 27.5 and 23.5 are under $3000 used,
and are very impressive. I've owned the 27.5 and found
it smooth, with expansive soundstage, solid bass and
excellent transient response. The 23.5 is similar with
greater power output, though I think the 27.5 has a
slight edge in musicality.