Straight tonearms without offset angle


In the October issue of Stereiphile, there was an article on a tonearm that had no offset angle and therefore had no skating force. The disadvantage of this is at the beginning and end of the record, the tracking angle error was much greater than what you get with an offset angle. For conventional tonearms that have an offset, and require anti-skating, which can never be perfect, the typical tracking error has a supremum of about 2 degrees, and according to online Lofgren calculators, this imposes a second-order harmonic distortion less than 2%. 

I have a single-ended triode amplifier consisting of vintage globe 45 triodes transformer coupled to 833A SETs which drives Magnepans. Such SETs typically have second-order harmonic distortion as high as 10% which does not hurt the sound. A straight tonearm without an offset would have a maximum, or supremum tracking error of just under 10 degrees. If this causes a second-order harmonic distortion of less than 10%, would not this be irrelevant in a SET system? Is there any way of calculating this, or has this ever been studied? 

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@lewm then let's say it is daring to go off the beaten path. It is the Reed 5T Lou. I would love to try both arms also, but they will not fit on my turntable and i have not current plans to  buy another. @larryi staying digital is the smart thing. What does that say about the rest of us. J Carr tried to convince me that the cantilever of my Atlas SL was deviating because I did not know how to set my antiskating correctly. When I told him I set it to 11% by WallySkater he said I should have set it to 14%. The cantilever has stabilized a few degrees towards the right channel, away from the spindle. It is still one of the finest sounding cartridges I have ever heard, but I shall not buy another. I paid $450 for what should have been a warranty repair and will move on. 

Thanks Raul. Interesting observations, I appreciate your input.

As for me, I find it hard to separate the design components of any gear in such a way as to make value judgments on on any specific design criteria. We may like a component, that part is easy to tell, what design elements contribute to that value judgement is beyond me.

I am the happy owner of the 7" Rigid Float CB (carbon fiber) arm. I met Akimoto-san in March near his home in Kamakura. He is a wonderful human being; communication worked well and he explained to me the important parts of his design, most importantly - as had already been pointed out  earlier - the complete decoupling from vibrations by means of the floating suspension: the arm floats in a viscous oil and is kept in place by a strong internal magnet pulling it down towards the rigid/stationary part of the housing w/o touching it. Imagine a ball in a bowl floating on a film of liquid: gravity will always pull it towards the center; now replace gravity with magnetic attraction, and you get the gist of the mechanism. It's comparable to a uni-pivot arm without the mechanical drawbacks (I myself have used the Woody arm for a long time: I loved its vivid sound, but hated the hour-long set-up routine). The second, and in my opinion unique feature is the complete freedom of placement: the arm comes as a self-contained (and quite heavy) unit that can be placed at any point around the platter, even away from the plinth, as long as the stylus can be positioned into a tiny hole in the placement template (a thin rectangular piece of plastic foil) above the platter. The entire set up, including VTF after cartridge mounting on the supplied head shell, takes no longer than 10 to 15 minutes. Akimoto-san holds a degree of mechanical engineering from the University of Tokyo, Japan's top university, and he is also a passionate audiophile. Combine the two, and you get this iconoclastic masterpiece, which sounds like it wasn't there at all. Needless to say, I bought the arm while we were still enjoying sashimi at a tiny place near the railway station - and never looked back. It's a true game-changer!

@reimarc My own experiencing of changing to a new Tonearm has similarities to your own.

I was first introduced to the TA at a forum event, where during a range of different equipment being demo'd, much of what was individuals designs for an Idler Drive, I heard a demo' that caught my attention.

At a later date, I was invited to the individuals home that had demo'd the set up that was certainly very well thought off and for me indelible as an experience.

I was introduced to the design that was selected to be used and the importance of particular materials being used as exchange materials, and the very tight tolerances able to be machined for the interfaces.

Further comparison demo's were done between TA's, with the result being I bought into this design for a TA, and have not felt to date a change is needed, even when being involved with a few changes that have been produced for the TA since my becoming an owner.