What you want is something that has inputs for the pre-amp and then outputs for the speaker. I think the D1 is more made for a computer running just as a headphone amp.
So what I would do is the schitt magni. Turntable to schitt, then schitt to speaker input. Use the headphone input on the front to play through them. Use the schitt as the preamp for everything with the speakers at a static volume.
It stays. Table to it to schiit to speakers/headphones. Phono stage brings low output from a cart up to line level so you to don’t want to take it it out.