Most difference? Overall it was the room - purpose made to Salford specs. For voice, turntable, I think. Went to full 3D air bearing with a massive platter. Then tonearm, then phono stage/pre, then amps, then cartridge and alignment of same. Cleaning records with 80KHz ultrasonics was in there somewhere. Since I began with Quad ESL’s there wasn’t that far to go, but the Reference voltage bias ladder from Electrostatic Solutions made a notable improvement, as did improving the LC delay line. A few tweaks helped too: damping the tonearm with Moongel, a sticky gel used for drum kit tuning.
Also helpful was close attention to power supplies, including massive inductors and power isolation transformers. And parts. Can’t say enough about quality parts, like nude Vishay resistors and air gap capacitors. Since changing to Canare microphone cable, haven’t heard anything significantly better, certainly nothing worth the price. Maybe try again after another good cartridge. Maybe.
For what it’s worth. YMMV.