DVS / Rekordbox / Through Mode with real vinyls

Hi!

I would like to play regular vinyls along with the timecode ones on Rekordbox & Interface 2. Nonetheless the THROUGH mode doesn't sound properly at all. The decks are properly grounded, the mixer & the decks are all set in PHONO.

My hardware is: Audiotechnica AT-LP 120X usb, Audiotechnica AT-LP 120 usb, and Pioneer DJM 250.

Do you have any suggestion?

Thanks