I do not think it can be. It was a part of RCA and (US) Columbia's "speed wars" wherein Columbia opt for a small hole record for the 33 1/3 rpm disks and RCA a large hole for 45s. RCA felt that by making a single purpose machine, they could force the market in their direction and kill Columbia's disks. Columbia countered with 7 inch records that played at 33 1/3. The greater universality of a machine that could play any speed no matter the spindle size (its easier to adapt down with a plastic insert) was a no brainer

Amy