Analog Corner #314: OMA K3 turntable & Schröder tonearm

Photo: Vincent Dixon

If you're going to spend a year-plus in COVID lockdown, it doesn't hurt to have a million dollars' worth of turntables keeping you company, right? That's been my good fortune. Sounds like a roomful, but it's only three: the SAT XD1, the TechDAS Air Force Zero, and the OMA K3 ($360,000, footnote 1).

You'll find this issue's cover girl either strikingly beautiful or homely. Visitor reactions fall strongly into one of those two camps, with nothing in between. I love the looks. Whatever your opinion, the K3's visual distinctiveness cannot be denied. The innards are equally unique.

Looking somewhat like the Guggenheim Museum topped by a heliport and a construction crane, the cosmetically finalized K3 arrived, coincidentally, in the afternoon of a day in which OMA's Jonathan Weiss spent the morning at the actual Guggenheim Museum, installing an array of his OMA Fleetwood Line of loudspeakers in support of "Anthem," artist, filmmaker, and MacArthur Grant recipient Wu Tsang's new commission, conceived in collaboration with singer, composer, and transgender activist Beverly Glenn-Copeland (footnote 2).

The production K3 replaced the cosmetically unfinished but intriguing prototype installed here last fall. The two units measure and sound identical, but Stereophile does not permit prototype reviews; hence the swap—though the word "swap" is inadequate to describe the drama and difficulty involved in lowering the prototype to the ground and hoisting the final curvaceous, slippery, 200-plus pound K3 atop the HRS rack. OMA manufactures a custom stand for the turntable, but space limitations—physical space, not column space—made it impossible to include it in the review.

A backstory worth telling
Much like the gestation of the Continuum Caliburn, the K3's design development and construction resulted from an almost-seven-year international cooperative effort involving industrial-level manufacturing acumen and academic expertise. Auckland, New Zealand–based hydraulics engineer Richard Krebs led a group that also included a Bucknell University team of professors and graduate students from the departments of engineering and physics. Also on the team are tonearm designer Frank Schröder (a familiar name to most Stereophile readers), architect/industrial designer Ana Gugic, and of course Jonathan Weiss, who in 2006 founded Pennsylvania-based OMA, short for Oswalds Mill Audio.

While the company is best known for its compression-horn loudspeakers and tube electronics, OMA has from its inception built custom direct-drive turntables using Technics SP10 variant motors set in a variety of massive, well-damped plinths made mostly of Pennsylvania slate and more recently of hypoeutectic gray cast iron; I enthusiastically reviewed one of those a few years ago.

Krebs is CEO of Hyspecs Hydraulic You want "jaw drop"? Visit the site. The company specializes in hydraulic manifold technology and whaddya know? The K3 sports interior manifolds filled with a special damping fluid. Krebs recently wrote to say he's spent 40 years designing and modifying turntables. Clearly, it's his hobby and passion, guided by engineering expertise, not fanciful ideas.

In fact, Krebs reached out to me a few years ago, asking if I'd spend some time with him and his son at the High End Munich show to discuss turntable design. After perusing his website, I felt wholly inadequate, but in another email, he assured me that my experience compensated for whatever technical accreditation I lacked. We met, and I told him what I knew and believed based on experience and what I'd gleaned from others with mechanical engineering knowledge. He confirmed most if not all of my views based on his technical knowledge and experience. We were on the same page.

921acorrn.omaspeed

Photo: Cynthia van Elk/OMA

Mr. Krebs and Jonathan Weiss gave me separate accounts of the K3's design background, which not surprisingly included the K1 and K2 iterations. The concept derives from vintage vinyl-cutting lathes, which Weiss pointed out were "designed as very expensive tools, built on the level of extreme-precision scientific, laboratory instruments."

Both Weiss and Krebs pointed out that on both the inscription and playback sides, cutting lathes must produce accuracy on the order of 0.005 microns, or, as Weiss put it, "the scale of a large organic molecule" (footnote 3). Only direct drive, the two aver, can track and accurately reproduce a record and not be slowed down, however slightly, by the transients and dynamic contrasts presented in a record's grooves. By the time a belt system's sensors notice slowing and compensate, they claim, the change is well "past due."

The human ear registers these speed anomalies as "softness, smearing," or as an impediment to "natural, lifelike musical flow." Neither platter weight nor bearing implementation can compensate, they say. So, rather than concentrate on average speed accuracy, the goal was to maximize "moment to moment" accuracy.

In addition to rotational accuracy, Weiss added, "any movement of the tonearm components relative to the platter" will result in apparent platter speed change—something SAT's Marc Gomez pointed out to me as an issue with the Continuum Caliburn's "floating armboard," though he acknowledges the tradeoff with the floating system's unrivaled isolation. All of these concepts, and others, are typically discussed by designers of ambitious turntables. Implementation is key, as is weighing the various tradeoffs incorporated into every sound engineering plan (as opposed to harebrained scheme).

A massive, cast-then-machined plinth
Cutting lathes were almost always made of cast iron; in the case of Neumann lathes, even the 66lb platters were cast iron. All were direct drive. To learn more about cutting lathe construction, refer to pspatialaudio.com/lathes.htm.

The K3's massive cast plinth structure, the design of which was aided by finite-element analysis (FEA) performed at Bucknell, is said to be critically damped, which means no oscillation and the fastest possible approach to equilibrium.

The casting is of the aforementioned high-graphite-content hypoeutectic gray iron. The plinth, the platter, and the circular armboard all feature internal chambers (the plugs of some of which are visible around the platter and armboard periphery) filled with a mixture of a special oil and particulate matter designed to deaden vibrations and kill resonances. The platter hides a matrix of vertically oriented chambers filled with this oil-and-particulate mixture, all located based on the FEA analysis.

Vibrational energy entering the system encounters the pools of oil and a sandlike material and dissipates as heat. The plinth features few joints and material dissimilarities so as to better evacuate noise-producing energy instead of reflecting it. Three feet, one terminated in a minimal-contact metal ball, act as efficient drains for vibrational energy.

Casting these parts to form the K3 chassis, Weiss told me, required "ultrasophisticated 3D-printed sand molds" (footnote 4) involving numerous iterations and final 5-axis CNC machining at aerospace mil spec levels. Weiss says the machining and metal casting could not have been accomplished with the technology of even 10 or 15 years ago. Any machinist looking at this complex, obliquely shaped casting would immediately understand the difficulties involved in machining the post-cast chassis. Bucknell University's Small Business Development Center awarded the K3 its 2019 Product Innovation Award.

K3's ultrahigh-torque motor
The direct-drive motor is a "bespoke" 18-pole, coreless-slotless, zero-cogging design based upon rotors and stators purchased as parts (after a six-month search for the right ones) and assembled with large neodymium magnets to produce what OMA says is "the most powerful motor ever used on any turntable." OMA says it's more powerful than the Lyrec motor used on Neumann lathes. OMA also says it has developed superior motors to drive lathes, but that's a story for another column.

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Photo: Cynthia van Elk/OMA

In this ingenious design, the stator clamps securely to the massive chassis bottom, which then becomes the motor housing. The rotor attaches to the bottom of the bearing sleeve. An unusually large-diameter (25mm, almost 1") hardened stainless steel alloy shaft bolts directly to the chassis, helping to maintain a high level of dimensional accuracy between the rotor and stator and between the platter and the armboard.

The unusually long bearing puts the powerful motor magnetics, which are located at the bottom of the platter/ bearing assembly, farther away from the cartridge than is typical on direct-drive designs.

OMA was after exceptional dynamic speed stability; the goal was a system that would perform optimally while playing a record. Krebs said that, with finesse, higher motor torque makes it easier to precisely manage speed fluctuations under dynamic conditions.


Footnote 1: OMA/Oswalds Mill Audio, Fleetwood, PA, with a showroom in Dumbo, Brooklyn, NY. Tel: (917) 743-3789. Web: oswaldsmillaudio.com.

Footnote 2: See guggenheim.org/wu-tsang-anthem.

Footnote 3: Unless someone has made a bigger one in the last few years, the largest known molecule is PG5, which has a diameter of 10nm, or 0.01 microns.—Jim Austin

Footnote 4: Sounds weird I know, but it's an actual thing: 3D-printed sand molds.

ARTICLE CONTENTS

COMMENTS
Anton's picture

It seems technology can now do what balsa wood and Exacto knifes used to do!

So cool!

https://darklanternforowen.wordpress.com/2015/07/04/diy-balsa-wood-tonearm/

There used to be a guy who built these out of wood and would show them at Hi Fi Shows back in the 80s and 90s...I apologize for forgetting his name.

It's nice to see materials science (can we still use that word, science?) catch up with engineering imagination!

ok's picture

attack/decay effect MF describes (or at least so I think) by simply placing/taking away some weight on top of my integrated. I have no clue how in the world is this really being done.

daveyf's picture

In years past, I recall a few high end companies that were concerned about the aesthetic appeal of their product, as such they hired someone called an ‘industrial designer’. These folks were tasked with coming up with something that would be aesthetically appealing, as well as workable with the electronics and functionality of the piece in question. I would assume that OMA omitted this step…

Jim Austin's picture

OMA employed a rather well-known industrial designer: Ana Gugic of Rome, who worked for architect Massimiliano Fuksas on the Shenzen International Airport and personally designed the Armani boutiques in New York and Tokyo.

Best not to confuse your own taste with good taste. :-)

Just making fun here (but the designer part is true).

Jim Austin, Editor
Stereophile

AnyMajorDude's picture

Ana Gugic seems to be employed as an architect at Dilber & Stolfi according to their website, where she is mentioned. But her profile does not even have a picture.

http://www.dilberstolfi.com/studio.html

„Dilber & Stolfi architetti is a laboratory of architectural, interior and industrial design, co-founded in 2006. They have since collaborated with luxury brands of the ready-to wear sector like Giorgio Armani and Gianni Versace.
They have hands-on exeprience on creating new interior concepts, and adapting them concepts to different situations throughout the globe.
Main projects include:
Flagship Store for ARMANI in Hong Kong;
ARMANI Caffè in Doha, Qatar;
VERSACE Boutiques and VERSACE COLLECTION Stores in China, Singapore and Russia.“

tonykaz's picture

Do you have any personal experience with this Transducer System ?

Ready to wear Luxury Garments doesn't seem a likely resume for what amounts to a ultra sensitive seismograph designer.

Then again, Versace Boutique in China might raise important eyebrows.

Tony in Venice Florida

ps. All this hype seems like an April 1st spoof, can it play "Certified Audiophile Recordings"?

Jason Victor Serinus's picture

When I was in China perhaps a decade ago, one saw signs for Versace in major cities.

tonykaz's picture

Thank you for writing,

Did you happen to see any Record Players when you were there ?

By the way, your reporting on that New Zeeland piece of electronics was pretty far over my head. It's brave of you to attempt stuff like this. phew. Still, I hope you continue with streamer examinations, you seem to have a knack for this type of technology. We need you and your opinions!

Tony in Venice Florida

Michael Fremer's picture

Are cosmetic. I heard an earlier iteration in a square box that perhaps was more suited to your tastes

jgossman's picture

This table is ugly as sin. It's not about money, or style, or panach. It's about just not being attractive. I am a Realtor also, and the ugliest most unlivable houses are almost always designed by Architects. The best homes are usually designed by builders on a napkin and handed to a draftsman who then hands it to an engineer to make sure it works. These modern table designs just prove to me that because an engineer CAN build anything doesn't mean they SHOULD. This table looks like a building because it was designed by someone who designs buildings. And if you replace the lower ring with a glass storefront, it's not a particularly attractive building.

Michael Fremer's picture

It's a very attractive turntable and building

Michael Fremer's picture

Or substituted sarcasm for the fact that the design didn't please you.

daveyf's picture

I guess beauty really is in the eye of the beholder...because maybe she should stick to designing airports and shops ( which would put her as an architect..not an industrial designer...minor difference!) I hope they didn't pay too much for her design!! LOL.
Best not to confuse good taste with the taste of OMA....
assuming they actually did use her design -??
Look at the plinth and the rough edges...for a paltry $360K!...Now who's making fun here.;0)

Gojira's picture

High torque of the motor and no vacuum suction?

According to my experience and numerous experiments, the biggest advantage of vacuum suction is the maximization of the transferred force from the motor to the records.
The smoothing of corrugated records seems to me to be only a pleasant side effect.

daveyf's picture

Having said that the aesthetics of this table are not what I think are attractive, I do applaud this company for attempting to move the SOTA as far as analog reproduction is concerned. If the results of their efforts are doing that ( which if we are to believe Mikey F, they are) then this is a good thing for the analog world...and music lovers in particular. The pricing strategy is something that one can accept or not, but if we take that out of the equation ( which Mikey F always does...) I think it is good that there are folks who seem to want to continue on with the endeavor of better and better analog reproduction.
If their design is successful, it is a good thing, as hopefully we will see similar advances trickle down to more sane pricing levels.

tonykaz's picture

kinda says it all, doesn't it?

Mr.daveyf describes the main feature of this device: insanity of pricing !

Why is Insanity the main Feature of Our Front Cover?

Tony in Venice Florida

MatthewT's picture

Where else are we going to read about gear like this? I'll wait for you to produce a similar product for 2 grand, a "sane" price for a TT.

tonykaz's picture

and. a whole bunch more.

I even bought a Goldmound with the Linear Arm for less than $2,000!

The Gyrodeks come in a wide range of metal surface Finnish

Tony in Venice Florida

ps. of course if you are just looking to spend money there are many people willing to help you.

MatthewT's picture

Asked you to produce a similar table to that reviewed for 2k, as in you make it.

tonykaz's picture

Do you have personal experience with this Record Player?

You do seem to feel equivalency of some sort is in Question.

Are you presenting a philosophical argument??

MatthewT's picture

With "insanely" priced gear. Go ahead, make us a TT to compete with this one as reviewed. Where is the Kaz TT?

volvic's picture

LOL!!!! I snorted my protein shake!

Anton's picture

Does your turntable compete with this one?

tonykaz's picture

How is it that you could know how well this reviewed device performs ?

Do you have any personal experience with this device????

Tony in Venice Florida

tonykaz's picture

Can you reveal your personal experience with this reviewed device ?

Tony in Venice Florida

tonykaz's picture

Why bother, the market is saturated.

There are about 70,000 known Vinyl hobbyists according to the people that collect data like this.

Steve G's latest guest suggests he only has Audiophile Grade recordings ( not all that many ) and has turned to Tape which has about 500 Audiophile grade.

Vinyl collecting is a pricy hobby who's participants collect hundreds of times more music than they will ever be able to play during the rest of their lifetime.

If a person is a Blue Note lover, buying records is necessary
If a person is a 78 lover, collecting is necessary.

The big Vinyl Houses are tending to show vinyl sales to be a Big Collector, speculator, Sealed, Unplayed, Never played, perfect, mint condition type of experience.

Garage Sale Vinyl is still out there. Fill a room with misc. vinyl for $1 per album.

Vinyl isn't about $250,000 record players, it's about a basement filled with sagging shelves supporting a disorganised 10,000 Albums.

One of Steve G's vinyl reviewing buddies revealed that he mostly only uses 100 or so records.

The KAZ tt is No Turntable

Tony in Venice Florida

ps. you can have your record player but well over 50% of the Audiophile Population don't.
ps. I'm not complaining about you, I'm complaining about Vinyl Hubris

Michael Fremer's picture

Is Stereophile a co-op? This is not in any way "your" cover.

tonykaz's picture

Hmm, oh really !

This is a Subscription Journal. Take away the Subscribers and you are left with an empty auditorium and no ticket sales. Who are you promoting for and to then ?

Comments like yours seem reflective of a hubristic attitude.

Thanks for writing,

Tony in Venice Florida

Siegfried's picture

Fever's rhythmic sounds like the hit of the 2 parts of castanets to me. Sounds sharp ans woody to my ears. I play a rip of the AP SACD via a "modest" 2500 euros Holo Spring 3 (add the price of HQP and of a Mac mini and of a NUC and of networking stuff to be fair). I'm not a vinyl hater, much much prefer the 45 Classic of Time Out over the AP SACD

Ortofan's picture

... really.

https://www.wsj.com/articles/its-time-to-retire-fever-1479505517

https://www.peggyleediscography.com/p/LeeResearchFever.php

Michael Fremer's picture

Finger snaps. Sorry.

Siegfried's picture

do yourself a favour and listen to AP's SACD through a decent digital front end. Maybe you'll get it now that you have improved your power supply... Or prove me wrong, get a first hand testimony, session footage, what have you. I listened to Ziggy Stardust this afternoon and much preferred my MFSL 33 over SACD and hi res remaster : I'm not a vinyl hater at all but when 500K turntables can't get it right, I have to mention it. Maybe the blame is on your Wilsons?

Siegfried's picture

https://www.peggyleediscography.com/p/LeeResearchFever.php appears to provide well documented confirmation that we actually hear finger snaps on her version. I can't find in your links well documented confirmation that we actually hear finger snaps on Elvis' version, just assumption that he retained the idea for orchestration. And "Finger snaps" sound distinctively different on Peggy Lee's and Elvis' versions

directdriver's picture

Place a candle above the spindle and you have a birthday cake.

I think it would look a lot better if they shave off the bottom four layers.

Anton's picture

But that would just add more labor and cost to pass on to the consumer.

;-)

Rodan's picture

Not having vacuum hold-down capability on a turntable at this level is inexcusable. Especially given OMA's "cutting lathe" pretensions. Can anyone name a cutting lathe that doesn't feature vacuum hold-down?

daveyf's picture

These days it seems there are a number of turntable manufacturers and others who are shooting for the $500k price point. How they come to these numbers is anyone’s guess, but I do question why they seem hesitant to break into the million dollar mark..and go even further still…$3m, $5m etc., Like I mentioned on another forum, the folks who are buying at $500k will have no issue buying into the millions…and the others are not there at the current price levels. To that, I would ask Mikey F…Is there a price point where you feel that the product is too high priced for what it offers? Inquiring minds and all that…….

Anton's picture

It is not the reviewer's job to say when the price is too high, only to comment upon the absolute performance.

It's like those unspoken rules of baseball.

It surprises me that the duPont registry does not yet have a Hi Fi section.

daveyf's picture

It is absolutely an option for a reviewer to make comment on how one product compares to another, and this certainly can include allusion to the value proposition.

Michael Fremer's picture

Comment on value

daveyf's picture

??? in relation to what???--

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