What gives? CD’s, Solid State?

" I'm beginning to think that it will take thousands of dollars for a DAC to get anywhere near the tonal accuracy and smoothness of vinyl,"

For a "hard" sounding SS based system, try a mhdt Paradisea tube DAC for under $500 used. That got me very close. If your system has some tube-like smoothness to start with, then try the mhdt Constantine SS DAC for even less. Though there are still differences in inherent sound between digital and vinyl sources, I've had no qualms with my digital relative to phono in either of my systems since obtaining these. Other than surface noise and other vinyl moise artifacts on some records, I am hard pressed to hear a significant difference between my digital and vinyl in most cases these days.

you might try leaving the CD player on repeat for a day, let it rest a day, then do it again, until you've logged something like 200 hours. it might make a big difference. also: are you leaving the CD player on all the time? (some CDPs don't need this as their digital circuitry stays on regardless - you can check with the dealer). speakers need break-in time too, so factor that in too.

Return to 100% tube chain to be sure.

Listen to Elizabeth.

A good source to buy those ferrite cores is Parts Express. Don't pay extra for "audiophile" type. They don't work better except they cost many times more.