Record With My New Imac Options

[bubblingpeter]

hi there,
last week i tried the new powerbook g4 of a friend of mine, fell in love with that wonderful creature, i decided to try out a program for guitar from native-instruments (guitarrig),i noticed that worked pretty well and with almost no latency, but the input volume was anyway to low, and when i tried to turn it up the guitar went in orrible feedback.
so i just ordered an iMac g5, that i guess should go way better on prestations, but i really don't know if it's going to work the way i want.
do i need an amplifier for my mixer to get the sound into the computer with a good recording level?
I don't know much about the internal soundcard either.
thanx for your opinions.
greets Pietro

[bubblingpeter]

thanx for sharing some idea...
i have a small mixer (without pre-amp) that i plug to the computer with rca cables.
i've always been a windows user, and few years ago i bought a CREATIVE SOUNDBLASTER PLATINUM, and i have to say that i never had a problem with it.
the thing that i want now is to write music, record (guitars and voice), and mix it on a better level.
and then i have another question...
trying the guitarrig on the pb g4 i noticed that when it's not on, doesn't come any sound into the computer until i don't open it... how is it possible? do i really need a preamp for my new mac if i want to play without a software?
and in the personal settings, am i able to split the internal mic with the line-in without record them both?it would be awful otherwise..
thanx
ciao