Direct Drive turntables

It never ceases to amaze me how many audio nuts propound theories without data. And when folks ask for data usually the answer is it's too complex to measure or we measure the wrong thing. Or, it's so obvious that no testing is necessary.

Are you really saying that none of you physics guys can figure a way to measure a) slippage due to stylus drag and its effect on dd versus bd, b) the similar effects of a vacuum and spindle clamp, and c) the constancy and behavior of the hypothesis that belt drive slippage averages a high mass platter even in the instance of variable amounts of stylus drag? Last, nobody has attempted to measure human sensitivity to pitch (speed) variation relative to the duration of measurement? If I were a manufacturer, I could turn a kitchen daisy wheel at exactly 33.3 if you gave me enough time to manipulate it.

FWIW, I vote that agon creates a science first forum where opinions must be backed by data (or references thereto).

FWIW, I vote that agon creates a science first forum where opinions must be backed by data (or references thereto).

there are lots of forums where 'prove it' is dominant. in those forums few focus on listening, and it's interesting how the 'sceintists' rarely if ever post about listening experiences. they focus on why this or that cannot be true because of their expertise. and pretty quick 'listeners' find another forum.

it is a personal decision whether to trust one's ears. i'm not passing judgement on anyone else's way of looking at things. but having to 'prove it' with data is not my idea of a good time. it's fun to compare perspectives on the basis of listening to music. and if it's not (or when it's not) fun then i'm gone, i deal with facts 6 days and 55 hours a week.

i'm not anti-data. measurements have a place in their service of the art (music). i think the balance of posting perspectives here on AudiogoN is healthy. if someone gets off track there is feedback questioning that perspective. do we sometimes ignore science? i would hope so.

that said, if someone wants to do a bunch of measurements and present them no one is stopping them. knock yourself out.

I agree with Raul in this case and he makes some salient points about 'evidence' or lack thereof vs theoretical postulations.
I also think it 'big' of him to recant as I seem to recall that up to a year or so ago he was a keen supporter of clamps?
What Daniel claims is 'theoretically' correct (and obvious)........if there IS slippage between record and mat/platter it puts the subject "beyond any serious discussion from my point of view".....however Daniel fails to provide evidence of ANY slippage let alone extent or magnitude?

There are many turntable manufacturers who specifically discourage the use of clamps on their designs (Linn, Rega, Raven).
There are also designers who advocate vacuum hold-down as well as clamps (Rockport, Continuum) whilst others recommend clamps but not vacuum hold-down (Walker).
I have heard all these designs and if 'clamping' and 'bonding' were essential to prevent 'slippage' of the record, then you would think its effects would be obvious in the resulting sound differences and ALL great turntables would have in common, their use of vacuum hod-down and clamping?
In my experience this is not the case.
For 30 years I have had a Rega Planar 3 followed by a Raven AC-3 and neither turntable sounds better with a clamp.
As Raul confirms.......one doesn't need to 'calculate' the effects of clamps vs no clamps? One need only listen.
Those turntables specifically designed with vacuum hold-down and clamps will no doubt sound poorly without them but those designed with the opposite philosophy will not necessarily sound better with their addition?

As usual in this hobby, 'absolute statements' rarely withstand scrutiny?

If you Dont like to clamp or vacuum but like the lp to stick you can use glue(preferrably removable glue). My guess is the slippage Will be less even though i havent qed.

Just to expand on Mike's comments...

I am reminded of Theodore Leavitt's remark that "People don't want a 1/4" drill, they want a 1/4" hole." I want to listen and enjoy music in my home; the equipment is simply the means to the end. I could care less if the TT is DD, belt or idler, nor do I care if I'm listening to solid state or tubed equipment, through horn, dynamic or planar speakers...I just want to connect with the artist and enjoy their art.

We haven't even begun to address the most important components: our ears and brain, i.e. how we are uniquely wired to interact with music. My son who has true perfect pitch, can not be in my music room if my TT's absolute speed is not spot on 33 1/3 rpm, but he is not affected by small speed variations. I'm exactly the opposite...go figure.

Having been lucky enough to have visited Mike's listening room (aka Vinyl Disneyland) on many occasions, his Dobbin's plinthed Garrard is my favorite source in his room...on most LP's. However, on some recordings, I prefer the Rockport.

Does anyone think that there is meaningful math or science that can explain this??? Anyone who knows me can tell you I'm an extremely data and numbers driven person, 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.