Has anyone had trouble with speed on their tt


I was having trouble with speed stability on a very expensive dual DC motor top of the line system of a well known brand from England. It was a terrible fight for years, I would get some good days and then the temperamental thing would drift or even radically switch speeds ending my listening session. I now have the perfect system and wondered if we could discuss this for other audio enthusiasts' sake.
zenbret
So, stop spending big money on TTs which may or may not hold an accurate speed. I stand by vintage tables with Quartz Lock. I can live without the extraneous info regarding arms, platters, etc. Just give me a consistent 33.3 speed and much of the other takes care of itself.
Dougdeacon said...

"No strobe (Timeline or otherwise) operates in short enough increments of time to detect micro-/pico-/nano-second variations. Knowing that a TT is speed stable across a time span of minutes tells us nothing about how stable or unstable it may be across a few thousandths or millionths of a second. Such short-period variations are just as audible and musically important, arguably more so."

Brilliant. This is so true.

Tonywinsc also touched on the same point.

IMO it is the reduction of these tiny speed changes that is one key to a TTs performance. Do we have a way to objectively measure this? Maybe, with some of the new optical speed sensors capable of measuring greater than 1x10^6 counts per rev, but I sure know that we can hear it.
Read Doug Deacon's last post again. He gets it.

Zavato said, "stick with a design that has an AC synchronous motor and a platter heavy enough to have some flywheel effect."

I could not disagree more. Flywheel effect caused by the platter is the reason many turntables lack micro dynamics, or sound lackluster in more general ways. It is a simple case of letting the platter control the speed, rather than the device assigned the job, the motor. That doesn't work, if you want a turntable that is truly precise.
The motor provides torque to hold speed. Platter mass is a component of the drivetrain system and affects how the system responds to changes in load and torque. A high mass platter does more for isolation of the record than the inertia effect. That's because more platter mass requires more motor torque. I have said before that if a motor can bring the platter up to speed in under one rotation, then it probably has sufficient torque. An undersized motor will struggle with the micro dynamics. The motor and platter are part of a system. Any one of the two out of balance results in poor performance.
Correct, Tony.

Except...

System inertia is key here, and certainly not platter flywheel effect like some turntable designers would have you think. I like high mass platters, but where the mass is located is critical, in my opinion. If properly done, the platter can be an extremely important component toward reaching the goal of optimal system inertia. I realize that my view goes against conventional thought on the subject, but I am convinced that the location of platter mass is a big deal.

One day maybe people will see that a platter should be more than a big round chunk of whatever, but right now there seems to be little thought put into platter design. Guys use a lot of different materials in lots of different combinations, but in the end they are still nothing more than big chunks of whatever for the most part. Isolation and tone seem to be the only concerns. That and marketing hype.