Back when the Telarc came out in the late 70's or early 80's, it was used to demo mainlyAudio Technica cartridges, which co-produced the recording. Not surprisingly, AT cartridges could easily track all cannons, as could Shures, Empires, and many other high compliance cartridges. of the day. The Mercury Living presence recording better showcases the music, but many play the Telarc to see if their cartridge can track it, which most, especially MC's, can't. I have several blogs about this subject on Audiogon, which you can look up, under my user name;One, especially, discusses this in my entry "Progtess?"