Hi David Thanks for the fine memories. My experience exactly - visual observation of the grooves in the track, and ownership of the Shure V15 as well. Sounded great on my C4000 and M400 and big VMPS tower (with 2 x 12" active woofers and 15" passive bottom slot firing sub-sub) back in 1982. Quite impressive in a small student condo. LOL. But the canons are short bursts right?