It's not theory--it's simple physics: P = F/S. The better the stylus, the larger the contact area, the deeper it will go into the record groove. From eliptical, to hiper eliptical, to Shibata (Audio Tecnica), Stereohedron (Stanton) and Fritz Geiger (Ortofon) shapes.
Come on, those cartridges were designed for radio stations back in the early 60's and the records back then (thick hard and mostly mono). There's someone in eBay who had the nerve to advertise the Pickering XV-15 as an audiophile product because it had been used in Swedish radio! I *do* have one of those--it was in my Father's fully automatic Garrard rim drive.
One of the first things I learned when I started audio (I was 14, 1977) was to use the best tip shape I could afford. That's why I still have VG++ albums from that era, in spite of drugs, rock and roll and my Tecnics DD.
Doug, stylus shape is so important that the cartridge I use is a DJ cartridge to which Kevin (KAB Electroacoustics) grafts a NOS Stereohedron stylus. Trackabilitty and musicality are excellent, along with the midrange of a $1500 MC. My Ortofon X5 MC has become the spare cartridge...
One's record collection would do a LOT better with a Shure M97. For real.
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