Direct Drive turntables

"but this is a place where subjectivity rules. IMO, measurements are useful in guidance, i.e. don't buy a 2W SET amp if your going to use 85dB efficient speakers, but the only thing that really matters is how the equipment meets your individual requirements to connect with the musicians."

Right on!

I think that the topic of record slippage is red herring. I am not aware of any evidence (listening or otherwise) that slippage is happening. However, there is plenty of listening evidence that some phenomenon is at play that fits the concept of stylus drag audibly influencing speed stability. This evidence shows up with or without clamping.

Jj2468, I'll echo what you said about measurements. It is too complex and we don't know what to measure. Both of those statements are often true, that is why you hear them repeated so often. Some things can be measured and some cannot (at least not yet). Some measurements are useful and correlate to good sound and some do not. To the point there is something going on in the world of analog that mimics (or is) stylus drag. It can be heard but nobody to date has been able to measure it, nor have I heard of a credible technique put forth to measure it.

Actually we do have some superb, highly sensitive instruments to measure with, our ears. Too bad many tend to trust them so little.

Here's an objective test that might be done.

If one were inclined and had the knowledge and time, one should be able to take a high res digital file created from various turntables as a source and then use computer algorithms to match the signal produced there to an all digital reference master of the same material to discern the differences. Then the question would become what accounts for the differences that would surely be observed.

This would be a fun project. Maybe someday after I retire and need something to keep me busy in addition to current hobbies, including just listening to and enjoying music.

Any EE students out there looking for a masters thesis perhaps?

Jfretch,

And it's not just in the piano, listening to Phil Woods right now and this trumpet has bight, power, delicacy that I just didn't have before on my SME 20/2.

Since Phil Woods plays sax, there must be something really wrong with your table. ;)
Sorry, couldn't resist.

You want to measure stylus drag ? No problem and very easy to perform at home with little more than 5 cent material and 15 minutes time.
BTW, my comment: "stylus drag - while still kind of a nebulous issue - is best addressed by securely clamping" - contains the (obvious....) technical statement that the record should be (if possible...) part of the moving system (the platter... to benefit from energy transmission and a few other aspects) and that stylus drag as such is indeed "still kind of a nebulous issue".
Which it is as it is depending on several periphery parameters.

Anyway - the test (which result will depend on a handful of individual parameters others may list according to their respective set-up...):

Do make a small mark at the outer rim of a record (mechanical scratch, cut of small color mark - whatever - but make it very tiny).
Do make a corresponding mark at the upper outer rim of your platter so that both marks do blend.
Now go and test.
Give it a full length LP side and see what is the result.
The results will differ considerably depending on weight of LP, slippage on surface of platter, dimensions of stylus, VTF, speed and 4-5 other technical aspects in the dynamic process.
Enjoy.
I performed this test 19 years ago in length and detail and decided to simply eliminate the possibility of stylus drag and lived ever happily after.