actually alot of you have been right
first of all....I know it's fizzy and everything, did,'t try to get the best possible sound but just wanted to have all the freqs in there.
so here's the solution with my comments (which are actually quite similar to SW's):
1. API - (as most of you have guessed).....I find this preamp to be way more open, natural and 3-dimensional sounding. it represents all the freqs and still leaves alot of space so guits sit well in the mix.
2. RME - I actually prefer this one for vox over the octo, but don't like it at all for guitars, I find is dull, muffled and flat sounding.
3.Focusrite - this preamp has actually surprised me, for little more than 600 for 8 pres (I also have the converter-option) these sound really good IMO, not quite as 3-dimensional and open as the API but somewhere between the RME and API...(closer to the RME though
) but IMO this preamp is definitely not as dull and flat sounding as the RME (at least not on drums and guitars).