Platter matters
The next time you’re preparing to play a record, try doing a little experiment. Once you have the record mounted and spinning but before you lower the stylus into the groove, lower your gaze to just below record level and look for a gap between the platter and the record. It helps if there’s a light source or a brightly colored wall behind the platter. You may discover a gap—that very little of the record’s playing area is making true contact with the platter mat or (if there is no mat) the platter. Another way to test this is to take a record you don’t care much about, put it on the platter, then tap with your finger in the groove area listening for a click as your finger pushes the record down and it contacts the platter surface.
Warps obviously lead to such problems, but even records that appear flat make scant contact with the supporting surface. Turntable and aftermarket accessory designers have recognized this problem for decades.
Up until the mid-1970s, most platters had built-in mats that supported the record on ribs or rings, and while they didn’t make contact over a large area, at least they made contact points more predictable. This thinking has come back recently, with limited-contact mats like the Ringmat, Hexmat, and Music Hall Cork Mat, all of which support the record over small areas.
The product that took this thinking to its ultimate extent was the rare Meitner AT-2 platterless turntable from about 30 years ago, which clamped the record at the label and provided no support at all under the playing area. Designer Ed Meitner believes that air is the best interface because it doesn’t reflect time-smeared energy back into the record.
When the AT-2 was new, I worked at
