Kuzma Air Line tonearm
The lacquers from which LPs are pressed are cut in a straight line, and that's how the LP groove should be traced. Even when set up perfectly, a pivoted arm describes an arc across the disc surface, maintaining tangency to the groove at only two points on that arc. Yet despite numerous attempts at building and selling linear-tracking tonearms, few remain on the market, and most are fraught with technical problems. Linear-tracking arms can be anything <I>but</I> linear, committing more sins of geometry as they meander across the record surface than do their pivoted brethren.
