Turntable speed accuracy

Thank you Dover.

Bill says the mods should make the transformer, motor and sense coils more reliable (longer life) so even if there is no appreciable performance upgrade it's still a worthwhile venture.

If it sounds better I'll be doing the victory dance.

Hi Henry -
Have finally managed to try the Sutherland Timeline on the Final Audio TT ( heavy mass - platter 19kg, string drive ( single silk thread ), AC motor driven by oscillator preamp( reconstructed sine/cosine waves) and power amp.

Testing with and without the record playing I have to adjust for stylus drag.
Both the KAB and the Timeline show the stylus drag. The net movement of the laser with stylus drag is about 2mm on the wall per rotation.

If I correct for stylus drag with the KAB then recheck with the Timeline it is spot on.

With record playing the Timeline is spot on as per the KAB.

Conclusions are I can sleep at night, and the KAB, or at least my one, is as accurate as theTimeline.

Hi Dover,
Congratulations. Good to hear :-)

"2 mm on the wall" is meaningless, unless you tell us the distance from spindle to wall surface, but in any case it sounds like the effect of stylus drag is very tiny, probably not audible and probably not worth worrying about. Unless I misremember some of the earlier posts, it sounds like the Final Audio, as you have equipped it, is among the best of the belt-drives in terms of resisting stylus drag.

I picked up a Timeline as I was interested in how our Scully Lathe was doing while cutting lacquers.

The Scully uses a 1/8 horsepower Bodine AC synchronous motor, driving a transmission that then drives the platter via a drive shaft.

With the cutterhead cutting on the plate, the laser does not move- over the entire side you can't see the change even when you use a micrometer. Not bad for being built in the 1940s :)