Dear Giglr: I think that you already have very good advise trying to achieve a better quality performance. Your analog rig is a lot lot better that what you report.
Other that the TT/tonearm set-up the cartridge set-up is very important too starting to have in the right position the tonearm/cartridge connection wires and like Thomasheisig point out: stylus clean. In the same way that you have to check the Tonearm/cartridge wires you have to check too that the tonearm cable is internally wired correctly.
The feedback from your speakers could cause that trouble too.
Now, if you have a second cartridge you could try it and see what happen.
Regards and enjoy the music.
Raul.
Other that the TT/tonearm set-up the cartridge set-up is very important too starting to have in the right position the tonearm/cartridge connection wires and like Thomasheisig point out: stylus clean. In the same way that you have to check the Tonearm/cartridge wires you have to check too that the tonearm cable is internally wired correctly.
The feedback from your speakers could cause that trouble too.
Now, if you have a second cartridge you could try it and see what happen.
Regards and enjoy the music.
Raul.