Turntable speed accuracy

What is the best way to verify results?

It depends on what results you're trying to verify.

With regard to general speed accuracy, a good strobe like the KAB or the Timeline both work well.

With regard to stylus drag or other very short-term transient events, my ears are far more sensitive than such tools, which lack a sampling rate capable of measuring variations which occur over mere nano-seconds. YMMV.

What is the most speed-accurate drive method?

A car on cruise control, which will transport you to the venue of your choice to hear real music. All TT drive methods are compromised, each in its own ways, so there's no answer to this overly simplified question.

And is speed accuracy really the most important consideration for proper turntable design or are there some compromises with certain drive types that make others still viable?

Whaaat? That's like asking if a red car is best or should we shovel snow or plow it. ;)

1. Is speed accuracy really the most important consideration for proper TT design?

It depends on the sensibilities of the listener. Some posters on this thread and very many TT designers seem oblivious to speed variations that drive me up the wall. I in turn am only just able to hear speed variations that drive my partner out of the room, screaming. OTOH, neither of us has absolute pitch to the extent necessary to identify a TT that's running 1% fast or slow but effectively resists stylus drag, yet my mother's absolute pitch can. What's important depends on who's listening.

2. Are there some compromises with certain drive types that make others still viable?

There are compromises with all drive types. Which ones are viable depends on the effects they have and how audible those effects are to you. Nothing about one design makes any other design more or less viable. Independent phenomena must be judged on their own merits.

Thanks Doug. I have heard three turntables with you and your partner and none drove Paul out of the room screaming. I guess that means the two Teres turntables and the VPI Aries we all listened to together had absolutely no speed variations. I believe two were tape drive and one was a belt drive.

A red car is more likely to be seen in a snow storm than is a white car, and if either has four wheel drive, it is less likely to get stuck.

Dear friends: I'm really surprised on almost all your answers on the overall subject.

Why surprised?, if there is true that some of us has no perfect pitch and can't detect " minute/tiny " speed deviations it is true too that other persons are way better in this regard and very sensitive about.
But, why that " no perfect pitch " or " I can't hear that minute deviations " or even " I don't care what I can't hear " where all these kind of opiniuons are only excuses to " protect " the TT already owned.

I'm not a designer of TT but if someday I take that road my very first and main target will be: no excuse, " perfect pitch " design: period.

If the customers can or can not detect it is does not matters, if during the recording proccess ( including those " great " R2R units. ) does not existed that " perfect pitch " it does not matters either even if the customers do not cares about IMHO any TT designer must look for that " perfect pitch " even absolute speed.

Dear audiophiles, please don't take it away the TT designers responsability. A TT exist because the LP needs to spin for we can listen and has to spin always at 331/3rpm or 45rpm: period.

We as a customers IMHO have to ask for excellence design level and not where almost everyone belongs: mediocrity/average level like the excuses that we don't have perfect pitch or that the electrical supply at home is non-adequate or that today is alittle " cold ".

How our hobby could improve when we are not asking for " more " for excellence but given reasons for the audio device designers does not cares about or at least does not cares enough about.

Halcro experiences with his Victor DD is not alone but several of us already experienced the same with some one of those DD vintage TT samples: exist a difference a difference that any one could hear.

Of course that if I own one of those BD dinosaur/mammoth we " accept " those minute/tiny speed deviations with no other explanation that " I can't hear " even if the timeline put in evidence the problem in our BD units.

Years ago and before the Timeline was in the market I posted several times that with heavy mass BD TT did not exist speed deviations due to stylus friction. Not easy to detect it but this fact does not means that I ask to TT designers : perfect pitch.

Our analog hobby is maybe the most imperfect reproduction medium where IMHO we have to take care in any single and " simple " stage where the cartridge signal must pass and where always suffer a degradation. As lower degradation on each one of those steps/links the cartridge signal suffer as better will be the sound that comes from our speakers and the higher the music enjoyment.

TT perfect pitch is one of those steps/links that degrade the cartridge signal even if we can't detect it or if " we don't care ".

As Teres pointed out: there is land for improvement about TT speed stability.

In this specific regard the DD experiences on many of us already showed that are a head to the BD ones.

Regards and enjoy the music,
R.

Greetings from Monterey Bay.
Just watching a spinning Micro Seiki 5000 with HS-80 inertia unit and a Sutherland Timeline which' laser point is so stable, it almost burns a tiny hole in the wall.
I do agree that speed accuracy is a conditio sine qua non with any serious turntable worth feeding a really good system.
There is indeed no excuse.
I too agree that it is quite a task for most any belt driven turntable.
It is however rather easy for most any thread driven high inertia turntable as well as for most every dd or idler wheel drive.
The elastic nature of most any belt - as well as string and tape - however makes it very difficult for mot belt drive tables.
Start measuring the homogenity of a given belt supplied with a bd turntable.
I mean measuring the mechanical quality of the belt.
Ripple and width/diameter constancy.
A very good reference here are the precision belts supplied by Basis Audio.
Belt driven turntables do need more attention here than the other 3 drive principles.
Greetings from beautiful california coast,
D.

4 German Ears for speed Tuning at Monterey Bay, California (Kuzma XL, Airline & Seiki 5000 + HS-80 Inertia unit, Thread Drive, Lyra Olympos, 2xFR-66s...)

Winner is ...

...the Owner.