I still have a pair of the original 804's purchased back at the end of 2002. They still sound quite good, and they are now a part of my Son's system. Like all 3-way loudspeakers, they require optimal placement.
With the refinements in the D4 model, they should be fantastic. In my setup, I never required much toe-in. You may have to experiment with moving them away from the back and side walls.
I have moved on to a smaller home and a 2-way stand mount loudspeaker from Wilson Benesch. They are matched the W-B Torus system. Don't give up on the 804 D4's.
I might suggest a different tube preamplifier. Have a look at the Quicksilver Audio Line Stage offering: https://quicksilveraudio.com/products/line-stage-preamp/
Happy listening