Source of Fremer's "1 arc second" claim?

I've heard stories about Herbert Von Karajan being able to distinguish between live and recorded sound coming from the speaker by detecting TT slow-down during orchestra "forte".  These are just stories - I have no reason to believe them, hut I'm far from being Karajan.  Piano overtones don't follow exact multiples of frequencies so pianos are tuned stretched - sharp at trebles and flat at basses to avoid beating.  Would it cause beat with other instruments producing exact multiples of 440Hz?  There are likely more errors like that in complexity of symphony orchestra and detecting 30min beat oscillations seems to be very far fetched.

@kijanki The whole "equal temperament" piano tuning is a whole other story, with splitting the comma. There is a nice book "How Equal Temperament Ruined Harmony", interesting read. For those of us who appreciate natural trumpet and other harmonics driven instruments such as tromba marina.

I completely agree that the complexity of music completely obliterates those tiny frequency differences. Heck, vibrato (if you must use it as an ornament) by far exceeds 1 Hz. 

My question, though, is: Anybody have any idea where Frermer comes up with this? 

Along with X - Ray vision another trait only Superman has!

Audiophile/phools  possess hearing skills superior to any mammal.

Some even treat this hobby as if they as playing an actual musical instrument 😂!

One time at an audio show, the exhibitor played LP I  had with me.

In the group of listeners were a few high falutun, self absorbed/proclaimed "experts"  The group made all those audio adjectives, and how great the recording and system was.

I was hearing a lopsided presentation?

Looked around and noticed the left speaker cable was disconnected!

Respectfully, I waited until the music finished and pulled the exhibitor aside to inform him....

I have massive tinnitus and 7KHZ hearing defict. 

All my TT experience suggests that speed constancy, the ability to maintain a single speed despite stylus drag, belt slip, belt creep, motor inaccuracy, etc, is much more important than speed accuracy (meaning centering a varying speed around 33.33 rpm but allowing for up and down drift of up to 1.0 rpm or even a little more). I probably have average pitch recognition, so maybe there are others who are bothered by 34 rpm (for example) vs 33.33 rpm.  I find that I am not especially sensitive to such a difference, provided speed does not vary. So I very much doubt the veracity of what MF claims here.

I can believe there exist among us the 'suprahearers'....while the rest of us laborious on.  Fortunately, I'm not one nor care to be.
Being able to discriminate that well in an urban environ would make one's head hurt.  Mho, though...

@tablejockey ...with you on the tinnitus & hf loss....my former I consider as my 'dial tone', the latter is why I wear aids...
Nice to hear birds again.... ;)

The 1 arc second claim likely is a quote from a turntable designer - likely a direct drive designer because they like to claim superior speed accuracy to all else.

I call it marketing bs or smoke and mirrors.

The boffins would claim it to be quantum entanglement.

There is a lot of unsubstantiated hyperbole (read: bs) in reviews. If you've been in the hobby any length of time, you already know this.

Precisely why his initials are MF.

Regards,

barts

Did I just join the nasty posters club?

"I can hear 2–3 cent difference"

oberoniaonia-

I'm with you on ability to hear subtle differences.

I play my guitar along with my favorite artist on LP, and find by way of the tuner, recordings are sometimes a couple of cents higher/lower than A440. Maybe that's the inaccuracy of my table,the recording...who knows?

Anyway, it's a way to REALLY hear if your turntable is speed steady- play the same chord against the LP to hear accuracy.

My setup gets a B+. Maybe an A- on good days.I hear wavering, not pronounced, but not accurate. 

It's not a $50K+ rig, so my blood pressure isn't redlining.

@barts I did not catch the alternative for the initials. Too funny! That, however, was not my intention.

@fatdaddy2 totally agree. Frequently a kernel of truth is augmented by acres of BS. Just was wondering what the source kernel might have been for 1 arc second. 

@tablejockey funny anecdote! 

Maybe that's the inaccuracy of my table,the recording...who knows?

Lots of factors, indeed. There is a general trend of pitch creep, with contemporary players going for a' = 444 Hz. 

@lewm 1 rpm = 3% = 4 cents which anything other than a manual gramophone can beat by a wide margin. 

The 1-arc-second likely originates from this turntable vendor whitepaper - Oswalds Mill Audio - K3 Whitepaper | OMA of which MF owns (or owned).  There are a number of errors in the white paper:

"...our device needs to actually physically trace modulations in a vinyl groove to the order of .005 microns."  The inherent surface roughness of the record reported by a couple sources is 0.01 to 0.005-microns (100 to 50 angstroms).  The RIAA curve is specifically intended to avoid the noise inherent to the record's inherent surface roughness, so the realistic smallest modulation is 0.1-microns, at least 10X the surface roughness.  And just to put the record's surface roughness into perspective, its surface finish (inherent to the material and pressing process) is finer than mirror polished stainless steel.  

As far as the arc-sec, read Minute and second of arc - Wikipedia, it's an angle measurement.  To apply that to a record of 12" diameter spinning at 33.333-rpm with outside groove tangential velocity of 51-cm/sec and inside groove velocity of as low as 20-cm/sec.  Converting 51-cm/s to radians/sec Angular Velocity Calculator = 3.3456 rads/sec which Angular Velocity Conversion Calculator - Radians, Degrees, Revolutions, and Grads = 191.74 deg/sec Degrees to Seconds Converter = 687,600 arc-secs.  Like the OP, the ability to detect 1-arc-sec is not possible.  However, angle encoders appear to have accuracies of 5-arc-sec and better accuracy_of_angle_encoders.pdf where "Angular measurement error (arc seconds) = bearing wander (μm) x 412.5/D" where D=mm.  If it's assumed a bearing radial wander of 5-microns and diameter of 13-inch, the angular measurement error in arc-sec is 1.2492.  But this does not take into account circuit noise, feedback error, etc. 

Like the 0.005 micron claim, the white paper claim of 1-arc-sec appears (being diplomatic) to be very 'optimistic'.  Otherwise, keep in mind that MF is not a scientist or mathematician.  He would help himself if he referenced the information source that is well out of his swim-lane, versus making claims that appear to be attributed to him.  

@antinn, for years I've read about Oswalds Mill Audio and Jonathan Weiss.  I've never seen MF associated with them in any capacity.  But that does not mean he was/is not.  So I'm curious, where you found that connection?

I don't think MF has anything whatever to do with OMA or even the K3, in a business sense.  Odds are he borrowed the K3 from OMA for an extended period of time, but I certainly do not claim to know that for a fact.  He may actually own it. And I don't think he is corrupt in any way, except subconsciously in the way we all are not to be trusted.  He says what he thinks. I think his main problem when discussing technical aspects of audio is that he has no scientific background to allow him to critique the BS he is fed.  (Someone else already said this, and I agree.) Very often he is just parroting what the manufacturer told him or what the manufacturer wrote in a brochure, uncritically.  On the other hand, we vinylphiles all owe him a debt of gratitude for his role in revitalizing this pursuit, and he is by no means a MFer. He could do with having a physicist or engineer available as a consultant to edit the tech aspects of his reviews.

@pryso

MF reviewed the Oswald K3 Analog Corner #314: OMA K3 turntable & Schröder tonearm Page 2 | Stereophile.com and per this article (last paragraph) confirms that he bought the unit - Oswalds Mill Audio K3 Turntable - The Absolute Sound.  

Gentlepeople

Michael's arc second comment probably came from a conversation I had with him about the speed sensing architecture in the OMA K3 turntable. The design sends a little over 1.3 million pulses, counts, to the motor controller every revolution. Slightly more than one count per arc second. This equates to a little more than 728,000 pulses per second at 33.33 RPM. The speed sensor assembly, like everything that exists, is not perfect. This means that  the time spaces between the pulses are not absolutely equal, even if the motor is running at a perfectly constant speed. The controller will sense these differences and signal the motor to correct a speed error that does not exist. The motor may or may not be able to accelerate or decellerate the platter in time to correct this non existent error but it will receive a current change none the less. 

The people who make the motor controller designed it to control systems that require much more speed precision than used in a TT. They also are well aware of speed sensor count errors. To mitigate this problem, the controller has a selectable function that activates a rolling average of the counts. With a few key strokes this can be set to 1, no averaging and 2 up to 8 count averaging. The controller also adds math to this function by giving more weight to the first count and little less for the second and so on. This function acts to smooth over the sense errors, resulting in more stable (smooth) and accurate rotation. It also acts to soften, smooth, the reaction, correction, of actual speed errors. When programming the controller, our listening panel trailed this function and found that it did indeed make an audible difference. The person making the program change did not tell the panel what change had been made, he only asked....better, worse, same?  Since it was software driven we could easily toggle it on/of or change the averaging number. In this way we could confirm in near real time what we were hearing. We also had a policy of revisiting the programming some weeks later to ensure that we hadn't make mistakes.

We settled on a rolling average count of 4.

When calibrating the speed to 33.33, 45 and 78 we simply adjusted the count command per second. Once close to the required speed we set about  incrementing or decrementing by 1 count per second. This meant that when targeting the required speed, we were changing the speed up or down by arc seconds per time. For a laugh, we listened to these changes, no one could detect a difference and no one was surprised. 

@lewm 

I happened to be in a whimsical mood as I read this thread, which I found interesting.  I've spoke with MF in the past, in fact he lives very close to me. 

I don't think he's a MF'er either.

Regards,

barts

@antinn, thanks for clarifying. I misunderstood your comment "OMA of which MF owns".

I also consider MF to be a boon to the vinyl revival, not a bad dude.

@richardkrebs, you talk about "we" in regards to the OMA K3 turntable. So are you a consultant to OMA? For those not aware, Richard has developed upgrades for some of the Technics SP-10 series of tables.

Or did I misunderstand that too?  ;^)

@pryso 

I designed the OMA K3 and K5 turntables. Jonathan then used an industrial designer for the aesthetics. 

My company provides the machined rotating parts and the K5 chassis. The cast iron chassis is made in the States. Both TTs are assembled by OMA. 

The "We" refers to a brilliant mechatronic engineer who helped to get the drive up and running and then a panel of enthusiastic friends who helped finesse the program.

Cheers 

@pryso, 

I also consider MF to be a boon to the vinyl revival, not a bad dude.

Please do not misunderstand my criticism.  MF has been steadfast proponent of the vinyl playback and deserves the recognition and compliments he gets for that.  But, on one more than occasion, he gets shall we say way ahead of himself regarding science & technology that he's not skilled in.  That's all.

Peace.  

@antinn, and peace to you.

My mention of MF was not a disagreement with your comments, only an acknowledgment of his tireless vinyl promotion.  I began listening to 45s, then LPs, long before digital, and I never gave up on them.  But I don't have the credentials to question his technical statements.

@richardkrebs thanks for that explanation. So MF confuses the adjustment period unit with threshold of audibility. Would be funny if it weren't so sad. Thanks for the clarification re that source kernel.

Interesting engineering issue going again at the accuracy vs. precision question and error correction. Using binning for data-noise reduction is certainly a tried and true approach. I run into it with microscope cameras.

Would be interesting to know what speed variation was considered audible by the panel. Though it may have more to do with sensor noise being reduced by binning. That begs the question of whether the company became victim of its own over-engineering. Making the measurement periods so short that the measurement error goes through the roof. Fascinating trade-offs! Run into that with electron microscopy reducing probe current for better resolution, but that decreases signal and increases noise.

@antinn @pryso Re trustworthiness of MF, when I notice some of his BS, I wonder how much other BS he is spouting that I don't spot. So I actively ignore him. To make things worse, I pointed out to the editor of TAS last year that this is nonsense. I am surprised that the editor is not reining in his authors. That is the function of an editor, have had a few of those appointments with some journals myself. That lack of editorial fortitude is a significant reason why I cancelled my TAS subscription again. So there is real harm done by spouting/publishing BS.

I know, it is just a hobby, for fun and all that. But that sort of thing turns fun & entertainment into annoyance. Don't need that. 

error correction on playback without an understanding of the error during the cut… sounds a bit …. well draw your own conclusions… 

Fremer should be granted grace…. imo

@oberoniaomnia

Yes, it is an interesting trade off. We did not need to go to the max averaging available, so I'm happy with the hardware design choices I made. .  The change from no averaging to averaging of 2 counts was astonishing, we all heard the effect. But we could hear no difference going higher than 4. This implies that data noise is low. 

To be clear, as you point out, this tuning is not a speed change of the equivalent of one arc second/ rev.

However it was a change to the granularity of the feedback/controller/motor loop in the order of one arc second. 

Cheers.