Phono preamp question


I'm slowly trying to upgrade my vinyl system to something that could be considered moderately decent, not necessarily high end. I have an older full feature preamp and am thinking in getting a separate phono preamp. I'm assuming the phono preamp would need to be connected to one of the line inputs. Would my preamp be the weak link if I get a good phono preamp to use with my existing preamp? Can a phono preamp be connected directly to the amplifier? FWIW, the preamp is an Adcom GTP-750. Thanks.
128x128kalali
The turntable I just bought is a Technics SL-3300 with an Audio Technica AT95E cartridge. Its basically new/unused and yes, I paid $200 and yes I think it sounds quite decent given what I paid. That been said, my original question was generic and just about using a separate phono preamp and trying to learn about options to make my old, LP playback only system (Adcom GFP 750, Adcom GFA 555, JBL L40) sound better. Thanks to those of you who made suggestions for reasonably priced phono preamps.
dekay, by the way, I have no doubt my current preamp has a much better phono stage than that $40 piece of crap you recommended. But thanks for taking the time.