I've tried a couple of externals including schiit mani which is recommended and sounded very good w/my Nagaoka mp 110 cart. which I have on Audio Technica ATLP5. I recently got an Emotiva PA-100 preamp to match an Emotiva Bas-x A150 amp. I hooked up my mani and was getting hum but I think it was the cables: Monoprice. So I ran TT directly to phono pre-amp on PA-100 and I could hardly tell any difference except there was no hum. So I think I'll stick w/built in preamp on PA-100. As far as advising. there are a lot of variables and different combinations--it's a crapshoot.