Is this the best tonearm in the world?

[Vinny]

Imagine all the poor bastards that have crossed your path in that time.

Not really, because we all knew what we were doing and talking about.

Some science, not much, but some,from someone else who alsom knows what they are talking about - only a humble polymer chemist though, quite a way down the piece -

Groovy-chemistry-materials-science-behind (acs.org)

There is plenty more online for anyone who wants to search.

 

[Tony L]

Vinny, it isn’t what you say that gets people’s backs up, we all seek knowledge, it is the aggression in the way you word it. A little writing skill goes a long way IME.

 

[sonddek]

We should get back to the subject of "the best tone-arm in the world".

I still haven't seen any information on its bearing. Perhaps it is a similar thread and magnet design to the Schröder reference, an incredibly elegant thing. As far as I can work out, the arm hangs from a single thread and is pulled downwards by a strong magnet under the bearing locus. Beautifully simple, but requiring careful and accurate configuration. I would love to hear one and I'm aiming to attend this year's Berlin Audio Meeting so that I can.

One thing that interests me about this bearing type is how much freedom the arm has to move in the longitudinal/time/drag axis. I have a Well Tempered arm which resists the drag force with a large object (golf ball) in a large cup of 100,000 Cst treacle, meaning that it can move in the time axis, but only very slowly. It seems to me that the Schröder suspension bearing resists the oscillating pull from the stylus with string forces upwards (filament) and downwards (magnet). I don't know if fluid damping is involved.

Can anybody elaborate on this?

 

[Tony L]

One thing that interests me about this bearing type is how much freedom the arm has to move in the longitudinal/time/drag axis. I have a Well Tempered arm which resists the drag force with a large object (golf ball) in a large cup of 100,000 Cst treacle, meaning that it can move in the time axis, but only very slowly. It seems to me that the Schröder suspension bearing resists the oscillating pull from the stylus with string forces upwards (filament) and downwards (magnet). I don't know if fluid damping is involved.

As I understand it the classic Schroeder magnetic bearing acts as a sufficiently solid chatter-free but highly damped bearing. More than stiff enough to do what is required with the forces in play, sufficiently damped not to simply transmit resonant energy straight into the armboard and behave like a tuning fork. It is a very clever design to my mind, though I have never heard one. The wooden arm tube being highly logical too. I’m not convinced it is as clever as the Well Tempered, which is a work of genius IMHO. A remarkably clear focus on actual requirements of the task in hand and total rejection of groupthink/marketing. A step far beyond what I describe as ‘a child’s view of rigidity’, which is sadly the prevailing view in arm design since the 1980s.

PS I have no idea how the OMA arm works, I’ve not watched the marketing video yet (I’ll do so later).

 

[Tony L]

Just watched the video and found it quite irritating as he spent fifteen minutes certainly giving the impression he understands the problems of tonearm design (I think he does based on what he said), but giving absolutely no detail on how his arm works e.g. how the bearing and counterweight decoupling actually work.

As suggested in my post above the more I think about tonearm design the more convinced I am that anything that even remotely resembles a tuning fork is a disaster. It certainly appears he/Frank Schroeder is of the same mindset. That said without detail it is hard to assess the thinking or to view it as anything beyond marketing guff. The Well Tempered arm and Frank Schroeder’s magnetic bearing arms to my very basic understanding successfully deal with the seemingly conflicting requirements of a truly stable platform for the cartridge and a way of not transmitting or reflecting energy by making the whole a tightly tuned isolated assembly that behaves in desired ways at given frequencies. The key to my understanding is to ensure any resonant energy generated by the cartridge and transmitted by the arm itself is unable to reflect back to the cartridge or be transferred into the plinth where the only hope of dissipation is high mass (which has huge problems to my mind). It is a fascinating topic as the many requirements are seemingly all in direct conflict with one another.

PS Error correcting(!):

The list of full vinyl front-end manufacturers really is as long as your arm; Rega, Linn, B&O, Technics etc etc etc long before one gets to the broadcast arena with the EMT, RCA etc kit he mentioned.

The adverse effects of counterweight mass and storage/reflection of energy back up the tube has been widely understood at least since the 1950s with the rubber-decoupling in early SME and Ortofon arms and there have been many more radical ‘hung’ counterweights etc in decades since e.g. the Roksan Artimez, 47 Labs etc. There is nothing new in that thinking at all. It is a known problem with many, many different attempts at solutions. I only wish he’d explained Frank Schroeder’s thinking here as it looked very interesting.

 

[sonddek]

The OMA video does not seem to shed much light on the bearing mechanism. Unlike the Schröder Reference, it appears that the mechanism isn't easy to see. Perhaps I will have to buy one to find out... ...[looks at price]... ...on second thoughts...

 

[Joe]

If you check out the video from 9 mins onward as he fiddles with the counterweight you can see a lot of movement of the arm wand..almost wobbles...does wobble.

What that means for the bearing design I am not sure...perhaps a conventional bearing but the arm somehow and to some extent decoupled ?

 

[Tony L]

If you check out the video from 9 mins onward as he fiddles with the counterweight you can see a lot of movement of the arm wand..almost wobbles...does wobble.

What that means for the bearing design I am not sure...perhaps a conventional bearing but the arm somehow and to some extent decoupled ?

It looked to be stable when he was handling the cartridge end, yet liftable at the pivot end, so my guess would be a conventional lateral ball race and a knife-edge or two-point vertical bearing. It didn’t seem like a conventional unipivot, and the mass is all in the wrong place for one of FS’s magnetic bearing designs. I’m thinking it is a fancy 3009!

PS I can’t work out the counterweight though. Is it just a damped hinge-joint?

 

[sonddek]

It's really interesting hearing your take on this, Tony. I am certainly guilty of taking the tuning fork/rigidity approach with my design. I consciously eschewed the idea of absorption of vibration energy, except in so far as one of the two arm tubes contains foam to damp the already limited ringing in a square cf tube, and the adhesive between the two arm-tube components is a quite different quality of material compared to the tube itself, which should help to flatten the peaks of some of the natural ringing frequencies.

I wanted to avoid fluid damping of the arm movement itself as I speculated that this was what made the Well Tempered arm a bit dull compared to the Ekos, and I imagine that damping of that kind can limit the arm's rapid response to the imperatives of positioning which the groove imposes - the very low subsonic frequency which the cutting lathe introduces by moving across the record at a variable signal-dependent rate.

I decided that coloration mattered less to me than dynamics. I can adjust to a slightly coloured sound - I listened to Kans for decades - but I can't as easily compensate mentally for loss of dynamic peaks and excitement ('punch').

It may be that my tuning fork is not so bell-like after all, but a more important design goal was absolute resistance to the oscillating drag impulse.

So much theory - so little time and money to experiment

 

[sonddek]

PS I can’t work out the counterweight though. Is it just a damped hinge-joint?

The counterweight looked like a two point coupling with the weight suspended by a thread. Basically an abseil/rappel. He showed that it could hinge upwards, but not downwards. That would be laterally stable except for extreme vibrations, but capable of absorbing some vertical vibration in the suspension thread. The asymmetry between upwards and downwards movement might be a bit non-linear, and were gravity overcome at all, as might be possible with strong vibrations down at the 'phonon' scale, the cartridge might see a higher instantaneous inertia when it moves downwards than when it moves upwards. Very interesting.

 

[Locheeboy]

NAH !
This is....



Feck this for a gemme o' sojers, ah'm aff tae Hi Fi Wigwam...

 

[Joe]

PS I can’t work out the counterweight though. Is it just a damped hinge-joint?

If you freeze the video at 9.27 it can be observed that the counterweight thread runs the length of the arm.....it is seen running in the upper part of it.

Why I don't know...it would only be in play when you lifted the arm ..or when playing warped records. ( why would anyone play warped records ? )

But you would think that a string running the length of the arm , and being under tension would act like a guitar string ?

lots of unanswered questions.

 

[Joe]

NAH !
This is....

That Audiomods arm is just a conventional gimballed arm design...vertical and horizontal ball races......well implemented but conventional.

 

[Tony L]

It's really interesting hearing your take on this, Tony. I am certainly guilty of taking the tuning fork/rigidity approach with my design. I consciously eschewed the idea of absorption of vibration energy, except in so far as one of the two arm tubes contains foam to damp the already limited ringing in a square cf tube, and the adhesive between the two arm-tube components is a quite different quality of material compared to the tube itself, which should help to flatten the peaks of some of the natural ringing frequencies.

I think your design is very clever, elegant and logical in many ways. It contains some genuinely new thinking and that is very rare in audio. My conceptual issue is I feel it ‘passes the buck’ to the armboard/turntable it is mounted on rather than actually following the problem through to conclusion. I suspect there is room for more thinking in the termination to the armboard.

As a starting point to understanding my thinking consider a ‘80s-90s Rega Planar 3 (any colour you like) fitted with its RB300. It is no secret these can be sonically improved beyond recognition by simply loosening the big bolt that holds the arm to the plinth. The optimal setting IME is that precise area where the arm doesn’t twist when you use the cueing arm, but no tighter than that. You certainly don’t need a spanner. Get it in that zone and it sounds so much better to my ears; bigger, more natural, more funky, less zingy or sibilant. Just better. I’ve found this true across so many things, e.g. my TD-124 armboard behaves in the same way. To tighten is to kill the sound.

The question is why? The best theory I have is it is ‘putting a crack in a bell’. It is killing the energy transmission to some degree. Stopping it ringing. I’m certain there are better ways of doing this by design, but in practice I listen to every bolt tension!

I wanted to avoid fluid damping of the arm movement itself as I speculated that this was what made the Well Tempered arm a bit dull compared to the Ekos, and I imagine that damping of that kind can limit the arm's rapid response to the imperatives of positioning which the groove imposes - the very low subsonic frequency which the cutting lathe introduces by moving across the record at a variable signal-dependent rate.

FWIW I’ve never heard an Ekos I’ve liked, so we may be starting from very different places. It always sounds a bit thin, sterile and zingy to me. I’d take an Ittok let alone an Aro (my actual choice was a Zeta). Never heard the SE or any full Keel-level Linns though, my Linn knowledge is firmly ‘80s-90s-era.

 

[Tony L]

If you freeze the video at 9.27 it can be observed that the counterweight thread runs the length of the arm.....it is seen running in the upper part of it.

I’ve just rewatched that section about 30 times! I don’t think it runs the length of the arm, there looks to be a knot just behind the top rear edge of the arm, i.e. the ‘suspension string’ is about an inch, inch and a half long.

PS Other things I’m not seeing: any sensible calibrated way of setting tracking weight (for best part of half a $million I’d not want to be faffing about with my Shure SFG-2!), or any visible anti-skate facility.

 

[Joe]

You're right.... just looked much more closely and indeed it just seems to tie off at the back of the arm.

Tracking weight....he says in the video at 11.05 that you loosen the counterweight and slide the whole thing back and forth to adjust. There seems to be no fine adjustment fitted to it.

He does go on about just how marvellous this counterweight system is claiming that it decouples the resonance from the cartridge from the arm...truly revolutionary he calls it.


Can't see it myself as the counterweight is hinged to the part that the arm is attached to. So, not detached ...possibly semi-detached .

 

[Tony L]

Tracking weight....he says in the video at 11.05 that you loosen the counterweight and slide the whole thing back and forth to adjust. There seems to be no fine adjustment fitted to it.

Time for a rant:

To my mind that is just totally unacceptable at that price. Ergonomics are important. A good user interface design is essential. To be honest this is one of my biggest criticisms with modern audio.

This is my turntable. A Thorens TD-124 fitted with a SME 3009. It is 1950s technology, though my specific example dates from the mid to late-60s. I use it because I like the sound it produces, but also because it is a simply stunning piece of aesthetic and ergonomic design.

To recap some 1950s functionality:

All four record speeds available with a fine-speed adjustment and strobe.
Built in clutch for fast start in a broadcast environment.
Pop-up adapter for ‘dinked’ 45s.
Easily levelled from above via thumb-wheels and built in spirit level (though mine is a little off!).
Armboard can be removed from above in seconds, the chassis can take 9” or 12” arms.
Once correctly floated the arm can be adjusted for tracking force without using a stylus balance.
The arm can be very easily aligned on its sliding base.
Bias, azimuth, VTA etc are all similarly simple adjustments.
Cartridges can very easily be fitted and removed for inspection or swapped.

The very best design is both functional and beautiful. Miss one aspect and the other is hugely diminished. In 2023 I expect more than more than this, not less, especially at these prices!

 

[sonddek]

I think your design is very clever, elegant and logical in many ways. It contains some genuinely new thinking and that is very rare in audio. My conceptual issue is I feel it ‘passes the buck’ to the armboard/turntable it is mounted on rather than actually following the problem through to conclusion. I suspect there is room for more thinking in the termination to the armboard.

I'm sure there is room for more thinking in every aspect of it, but as Steve Jobs said, "real artists ship". Tempo and money are also resources in the great compromise.

As a starting point to understanding my thinking consider a ‘80s-90s Rega Planar 3 (any colour you like) fitted with its RB300. It is no secret these can be sonically improved beyond recognition by simply loosening the big bolt that holds the arm to the plinth. The optimal setting IME is that precise area where the arm doesn’t twist when you use the cueing arm, but no tighter than that. You certainly don’t need a spanner. Get it in that zone and it sounds so much better to my ears; bigger, more natural, more funky, less zingy or sibilant. Just better. I’ve found this true across so many things, e.g. my TD-124 armboard behaves in the same way. To tighten is to kill the sound.

Yes, you are right, and I've done that experiment many times. My Rega arm definitely sounded better when it was only just not quite too loose. My Ekos also suffers from a loss of ease and power when overtightened. Strangely I have not encountered this phenomenon with my own arm, at least it's not very noticeable if it's there at all, and I don't hear much difference between the various mounting methods on Amadeus, 301, SL-1210 and LP12. One possible explanation is that tight coupling affects the draining of vibration energy from the arm in such a way that it is overdamped, and therefore sounds more natural with less coupling. That analysis, no doubt too crude but perhaps a reasonable first approximation, might also suggest a reason why my arm does not seem to exhibit the phenomenon: the very low pressure between the pivot point and the thrust surface means that the beneficial decoupling occurs between the suspended arm and the mounting pillar, and further decoupling at the pillar base is more or less redundant.

Bolt tensions on my arm don't seem to be of much importance. Maybe I'm deaf, but I can certainly hear it with Linn and Rega arms, just not mine.

 

[sonddek]

Time for a rant:

To my mind that is just totally unacceptable at that price. Ergonomics are important. A good user interface design is essential. To be honest this is one of my biggest criticisms with modern audio.

This is my turntable. A Thorens TD-124 fitted with a SME 3009. It is 1950s technology, though my specific example dates from the mid to late-60s. I use it because I like the sound it produces, but also because it is a simply stunning piece of aesthetic and ergonomic design.

To recap some 1950s functionality:

All four record speeds available with a fine-speed adjustment and strobe.
Built in clutch for fast start in a broadcast environment.
Pop-up adapter for ‘dinked’ 45s.
Easily levelled from above via thumb-wheels and built in spirit level (though mine is a little off!).
Armboard can be removed from above in seconds, the chassis can take 9” or 12” arms.
Once correctly floated the arm can be adjusted for tracking force without using a stylus balance.
The arm can be very easily aligned on its sliding base.
Bias, azimuth, VTA etc are all similarly simple adjustments.
Cartridges can very easily be fitted and removed for inspection or swapped.

The very best design is both functional and beautiful. Miss one aspect and the other is hugely diminished. In 2023 I expect more than more than this, not less, especially at these prices!

I'm ashamed! the only thing I can say in my defence is that I hope my less convenient arm sounds a bit better. Ironically, I ended up designing a less convenient arm because I didn't have much love for the pair of 3009 II on the two Garrards I rescued. Looks like Messrs Weiss and Schröder have made some of the same mistakes ;-)

 

[Tony L]

I'm ashamed! the only thing I can say in my defence is that I hope my less convenient arm sounds a bit better.

I’m criticising the OMA as it is clearly a cost no object design. There is no excuse to come up short on any parameter sonically, ergonomically or aesthetically at that asking price IMHO. If I’m finding that sort of cash (which I obviously couldn’t) I expect absolute state of the art in every aspect of design.

PS For clarity: I certainly wasn’t having a dig at you or your product. That just wasn’t my intention at all.