Every post here misses the most important and overlooked point in this discussion of speed accuracy. While it's a laudable and important goal, fetishing on speed perfection as the sole goal of turntable design misses that the eccentricity of virtually every record you own will produce greater effective speed error than any speed deviation found in a properly executed design, regardless of whether it's belt, direct drive, idler wheel or whatever. Records and record playback is a terribly imperfect technology. That it still sounds the best despite the imperfections is miraculous. If you want perfection get a CD player.
---Michael Fremer
---Michael Fremer