Measuring TT Speed


In measuring my tt speed I am seeing the lines on the strobe bounce back and forth, not holding steady. This is a belt tt with a dc motor setup with a closed loop controller, and ideas on what can cause this? I am thinking the belt may be to tight, it is a new belt BTW...
jsman

Showing 1 response by elliottbnewcombjr

Have you ever been aware of a speed change when listening? If not, try to ignore it.

Wonderful Thorens TD 124, idler wheel drive, mirror constantly reflecting strobe on underside of platter: each session the motor had to warm up before you adjusted it to get the built in strobe lines steady. then after a while, check, might be a speck slow or a speck fast.

Not that I heard it, just when changing lp's I saw it. And that's a 7lb or 9lb platter to behave like a flywheel, with the most precise bearing I have ever seen.

Direct Drive, not quartz, similar, warm up needed, but steady after that.

Direct Drive, Quartz Locked, ON, walk away.

The speed controls are nice, but wait 10 minutes for warm up, and then only a minor adjustment should be needed, their larger range is for purposeful audible changes.