Turntable speed accuracy

Very well put, Learsfool. The importance of coherent rhythm can't be stressed enough. On a related note (and the subject of another thread), it is ironic that in spite of it's technically "superior" speed stability, digital recording technology can suffer from rhythmic blandness. It is not only rhythmic accuracy from one point in time to another that matters, but what happens in between; the motion moving away from one point in time and leading up to another. That is what gives music it's thrust and swagger.

this is almost humorous, you folks are arguing about problems the older among us had to deal with in Dual and Phillips TT's of the 70's and 80's.

If speed of a TT is constantly off the musical pitches will be off. Since all speeds are off proportionately, harmonic structure will still be intact. If its badly off the spoken/sung word will sound distorted because we are sensitive to the cadence of speech. Trying to play an instrument along with this becomes silly because you have to mistune your instrument.
If the speed is variably off that becomes wow/flutter... thats musically unacceptable.

What makes the finest turn tables is damping/filtering vibration at the micro level to prevent vibration reaching the arm and platter that would superimpose on the stylus tracked vibration, distorting the electrical signal created in the cartridge and played back as sound in your system. As an example put a vibrator on your cheek and try to sing... thats what a badly isolated TT does even with perfect speed.

You can consider direct drive the equivalent of attaching a vibrator directly to the platter... Denon tried to sell a lot of these.

Next best is belt drive... the motor still vibrates but the belt provides isolation in power transfer. But a platter mounted on same sub chassis as motor still sees vibration transfer through the chassis. Rega follows this model.

Optimal is belt drive, suspension TT where platter and arm are on an independent subchassis... both are isolated.
Linn Sondek,the AR and Sota follow this model

And there are the exotic designs ( I believe I once saw something that floated the platter suspension in the equivalent of jello)

Davide256: "What makes the finest turn tables is damping/filtering vibration at the micro level to prevent vibration reaching the arm and platter..."

Isn't this "vibration at the micro level" a form of movement and doesn't movement consist of timing? So a turntable that takes care of damping/filtering vibration automatically make it the finest disregarding strict attention to speed issues? Now I know where those toy motors are coming from...

Davide256: "You can consider direct drive the equivalent of attaching a vibrator directly to the platter... Next best is belt drive... the motor still vibrates but the belt provides isolation in power transfer."

You're repeating the flawed notion that Lewm already objected to in one of the above posts. I just cannot fathom someone discussing about "the finest turntables" without thinking about speed accuracy or the importance of speed accuracy as if that's a dated issue. I don't know what else to say. It reminds me of a Chinese saying about a cowhide lantern......

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Davide256, With all due respect, you are wrong. Linn is OK right after the suspension is tuned and for the next week thereafter. AR and SOTA, up to and perhaps not including their very latest TOTL models, are seriously flawed as regards speed stability. My SOTA Star Sapphire III was a distortion generator on piano music. Have you ever heard a real piano? Do you really like stretch-y belts and belt creep that much? And AR? A classic, yes. A bargain in its day, yes. But an example of how to build a speed-stable tt? Puh-leeeeeze.

Also and parenthetically, you don't understand the mechanism of a direct-drive turntable. I think I mentioned this to you somewhere above this last post. Do some reading on this subject. The issue in direct-drive is not noise but designing a motor that is free of cogging at slow speed. (The DD motor has to turn at 33 rpm, whereas belt drive and idler drive motors turn much faster. This tends to make them noisier than DD, not quieter, but a little easier to mask the cogging effect.}

But the syntax of your post actually suggests you like direct-drive better than belt drive. (You start with your criticism of direct drive and then begin your discussion of belt drive with the phrase "next best", implying dd is better, which it actually is when done right, IMO.)

Hi Thuchan,

I do understand that your system stands in Bavaria and it is located on-speed outside of Munich :-)

Also, I like following this attitude of "but sometimes fast driving"...out on the road! :-)

Always happy listening!