Do you use your bdp’s hdmi output? Have you tried to see if the digital coaxial or optical output to your avr gives you better sound than hdmi for cd playback.
Another option is to get a cd transport and use your avr’s internal dac. You have a totl denon avr which has good dacs.
If you want to add a tt the basic Rega, Project, Thorens tt w/ factory cartridge would be a good starting point, but you probably want a better phono preamp, like a Schiit Mani, instead of the avr's afterthought phono stage.
Another option is to get a cd transport and use your avr’s internal dac. You have a totl denon avr which has good dacs.
If you want to add a tt the basic Rega, Project, Thorens tt w/ factory cartridge would be a good starting point, but you probably want a better phono preamp, like a Schiit Mani, instead of the avr's afterthought phono stage.