be sure you don't buy any "preamp", but only a Phono preamp;
phono preamps have built-in equalization.
otherwise, the low freq. will be very weak and you'll get shrieking high frequencies.
this is a standard (RIAA) equalization curve, and the reason is so that low frequencies don't take much space on the grooves.

See: http://www.blu-ray.com/community/gallery.php?member=Gelli
or: Axiom Gallery