But Syntax, is the Kuzma constantly too fast by a fixed amount while playing LPs, that is, regardless of stylus drag? If so, that is a fault remediable by an appropriate motor controller and not a black mark against the Kuzma.
Tony, I just cannot agree that a tachometer, no matter how good, is potentially superior to the Timeline for detecting micro-variations in speed, unless it would run off the rotation of the platter by a direct and perfectly non-compliant mechanical linkage, with no "belt creep". And then you'd have to stand there and watch it or run a recorder off of its output. In fact, Denon produced such a figure for use in their ad copy for the DP80; they show a very low level wiggle in an otherwise straight line, representing 33.33 rpm on the Y-axis, with time on the X-axis. But I doubt that the data come from a tach read-out. I don't recall how they derived it.
Peter and Henry, So if the single laser flashes six times per revolution, that would be about every 0.3 seconds. That's pretty near an instantaneous read-out. I wonder how it compares to the response time of a very good servo correction system. Maybe Richard knows.