As I read through this thread a part of me couldn’t help but wait for the punchline that the real culprit was a phono stage that is overdoing the bass. I’m a little twisted that way. Interesting that adjustments to the source and cabling made enough difference to satisfy the OP. Because things usually come down to implementation, it always amazes me when the least complicated isn’t far and away the best. Reading physical media in real time without error correction seems complicated.