I would approach the problem by looking at the whole signal chain instead and try gaining at each stage.

-The mic : cold sounding mics usually will get you a cold sounding sound. You might want to go to a shop and compare your mic with other ones plugged on the same system. No point in going further if your mic is not up to it
-The cable : yes, even the cable counts. Go for custom made hi quality cable (not crazy stuff, just plain well shielded pro cables). Many shops will sell both the "family karaoke special" as well as pro quality one. They look almost the same but the price tag will certainly differ, and so does the sound, you would be surprised...
The preamp : In my experience you don't need a really expensive preamp to get a good sound,...at least until the mic up front is about the same price as the preamp ! Even the new VLZ pro Mackie ones you find on their small mixers beats a lot of supposedly good stuff. I prefer to stick to a clean preamp and have it drive a tube "warming" box of some kind. At least you can choose where and went you want some dirt.
-The warming : try test and evaluate all you can get your hands on. It is all a question of taste.

-Before getting to Eq and compression we should leapfrog to the last stage first and speak of converters : many budget digital recorders have very average converters. I find that these "basic" converters tend reproduce high level content (near max) pretty well, but they tend to "swallow" low level content, giving a "dry" or "cold" sound.
That is where a well used compressor/limiter before recording will give you more confidence to drive the level near (but not on) the limit. You can gain 6db or even more on some instruments and this can make a TREMENDOUS difference. Acoustic guitar, voice and bass are good examples of this.
The snag is that you will have to make the right decisions as far as setting the compressor, and this takes a little experience (and quite a few mistakes...). In your case I would go for a DBX
EQ : trim elegantly excess lows and low mid if your eq allows doing it in a not too wide bandpass fashion, *before* compression. If your eq is super simple (like one low shelf only)then go carefully so as not to "empty" the sound!

Summing it up :
Mic ->cable->preamp->"warming"->eq->comp/lim
->recorder+converter

A special note concerning basses and el. guit. These instruments usually want to see an input impedance of at least several hundred kOhms. Never plug them in the line input of your mixer unless they have active cicuitry : they will sound dull and thin.
Boss or other good stomp pedals usually have FET input stages with high inpedance : use one as a makeshift DI box without turning on the effect between the instrument and the preamp
Instrument ->cable->DI or Stomp box ->line in
->"warming"->eq->comp/lim ->converter

good luck

Great advice from MkH

I recomend a mic pre / compressor / eq / valve unit called.

in Europe - TLA 5051
in North America -HHB Radius 40

a great value, usefull tool - in your budget range I belive.

(It partners up well with a Neuman TLM 103 BTW)

:)

interesting thing this boss pedal in front of a line input - what about instrument inputs on preams? I never got a real good sound going with my bass or guitar directli into a Instrument input ( such as Drawmer 1960, 737, voxbox, ....)

why??

do I need to use a D.I. ? :w:

lukee,
I have gotten a pretty good sound using the MP2NV's DI on my Jazz Bass. It didn't sound all that remarkable when soloed, but when I engaged the loading and impedance, the bass just came into focus on a recent mix.
-dennis

I recomend a mic pre / compressor / eq / valve unit called.

in Europe - TLA 5051
in North America -HHB Radius 40

a great value, usefull tool - in your budget range I belive.

Julian,

I've noticed that you like TLA/HHB stuff.
Some people (Fletcher) just can't stand it.
I've also heard that the "white" TLA series is based on IC's and only has a tube in the buffer amp section. Since IC's introduce cross-modulation distortion my question is how audible is it.
Or in general - is there a major sonic difference between this unit and boutique class-A products?

>>I've also heard that the "white" TLA series is based on IC's and only has a tube in the buffer amp section. Since IC's introduce cross-modulation distortion my question is how audible is it.<<

I find that white TLAs don't overdrive in a interesting fashion as some older grey ones did. Just an opinion of course...

Mark

Now I've got a bunch of tube gear and tube mics, and am nuts about tubes, but I think a crucial aspect to getting a natural "warm" (to me this means alive, rather than dead on the morgue slab) sound is to use good converters. A lot of "digital coldness" is just weak converters. Whatever other killer gear you use, it's all going through the converters, so it will be no more lifelike than the converters are.
I would recommend holding out for the really good tube stuff, if tube stuff is desired, and get some classy converters (happy with my RME ADI-8 DS's, but not cheap) and work on the rest of the "signal chain": great instruments, good mic technique and above all placement, all the old school skills.
Ted

BTW, I still haven't found much use for compressors meself (ignorance, I know), and rely mostly on good musicianship dynamics and retakes to get healthy levels to 24 bit digital. I'm sure that eventually I will get a rackfull of compressors, but they way I work I often have close and distant mics on a subject and am very leery of disturbing the 3-D stereo picture with compression...
Ted