Welcome to RO! The K2 is a great mic for vocals, both male and female, acoustic guitar and percussion- I have 2 of them. i suspect it will be equally great on acoustic piano but haven't had the pleasure yet-

The only preamp under $350 I could recommend is the rane ms1- In the lower range I also like the grace 101 but now we're talking 600 bucs... :D

thanks so much. ill check them out

In the really low price range, you might take a look at the M-Audio Audio-Buddy. It is surprisingly good with most mics. Only real problem is that is does not give full 48V on phantom power, but many mics does not care.

Gunnar.

No one else will probably agree but check the specs and the sounds
of the ART (duck) TPS I can record vocals with this that are great sounding.The "voicings" Just sound like EQ's to me like the cheap radios with "jazz","Rock"or "voice"buttons for presets.
I usually use my ear and spin the knob. I have the old one but the new one is around 100.00 a channel and has variable input impedance! I love recording with my cheap 200.00 preamp then pissing my friend off with my recordings at his studio with his $30,000 bunch of preamps!
(But I am very good at post eq, multiband compressor & silky exiter!)
Anyway for cheap it is very good.
You can also buy a presonus eureka for about 420.00 shipping included (little more than your 350.00 limit but my new one sounds VERY good!) Many people are talking about this box favorably unless you have super expensive stuff and would never admit that you thought it sounded good.

Another vote for the MS1b. Freakin' amazing from a crappy little box. Ugly, too. But clear, clean, etc.