mobanmarketIt started one evening when I was killing time watching YouTube videos and stumbled across a 2017 talk given by Jonathan Carr, Lyra’s brilliant cartridge designer (footnote 1). After discussing his design and Lyra’s manufacturing processes for about 18 minutes, Carr opens the floor to questions. Someone asks which of the many cartridge setup parameters he feels is the most important. I was floored when the first thing Carr said was that “horizontal tracking error is not very important at all.” What? I couldn’t believe I was hearing this from the guy who writes owner’s manuals with super-specific specifications, like tracking force measured to a 100th of a gram and loading recommendations with wide but oddly specific ranges like 97.6 to 806 ohms. Did he really believe that the tonearm geometry calculations of Löfgren, Stevenson, et al, weren’t such a big deal?
For decades I have painstakingly used the best tools available to perfect these settings with every cartridge I install; now a guy whose opinion I respect deeply is saying it’s not very important.
Carr went on to explain how pretty much every tonearm aligns the cartridge with an overhang and offset angle to minimize the tracking angle error, but that this also results in an undesirable skating force, which needs to be counteracted with some kind of antiskating device on the tonearm. His belief is that the counteracting skating and antiskating forces rob the cartridge of some of its energy and dynamics, resulting in sound that’s less lively and engaging than it could be. Carr then spoke about how some audiophiles, especially in Japan, embrace the use of what’s known as a pure straight tonearm, with no offset angle, thereby minimizing the skating force and the associated need to use antiskating. But this approach comes with a price.
Because a record-cutting lathe cuts the lacquer in a straight line, in a perfect world we should use a tonearm that keeps the stylus perfectly in line with the groove across the entire side of the record. Over the years, there have been many linear tracking tonearms that do this with varying degrees of success, including models from Clearaudio, Eminent Technology, Goldmund, and Bergmann. More recently, there have been designs that look more like a traditional pivoting arm but maintain perfect alignment with the groove through the use of a rotating headshell (as with the Thales tonearms) or by moving the pivot point (as with the Schröder LT and Reed 5A). But linear arms are complicated beasts; some require drive motors, air compressors, or a multitude of bearings and joints. The Reed 5A uses a laser beam, which would undoubtedly make Austin Powers happy.
Long before anyone considered trying to make a linear tracking tonearm, some very smart people with excellent math skills figured out how to minimize tracking angle errors as the stylus moved in an arc across the record. If you moved the stylus in an arc that passed slightly forward of the center hole, then cocked the cartridge inward by a few degrees to match the angle of the groove at that point, the stylus would pass through two points at which it was perfectly in line with the groove. Between and outside those points, errors would be greatly reduced.
This approach was first proposed by Bela Harsanyi in a French patent as far back as 1908. It was expanded in an article titled “Needle Track Alignment” by Percy Wilson in The Gramophone in September and October 1924. But this was still the era of windup acoustic gramophones with steel needles. It wasn’t until Swedish professor Erik Löfgren’s groundbreaking 1938 paper that modern thinking about phono cartridge alignment became firmly established. Löfgren proposed three alignment strategies (Löfgren A, B, and C), with Löfgren A being the preferred alignment when both overhang and offset angle are adjustable.
Today, Löfgren A is commonly referred to as Baerwald, and therein lies an interesting story. Because Löfgren’s 1938 paper was published in what at the time was Nazi Germany, in a relatively obscure German-language publication, it wasn’t until H.G. Baerwald’s 1941 article, Analytic Treatment of Tracking Error and Notes on Optimal Pick-Up Design, published in the Journal of the Society of Motion Picture Engineers in December 1941, that this work gained widespread recognition. Baerwald presented his own calculations, which produced results identical to Löfgren’s, and while he gave a nod in his paper to the Swede, for many decades it was assumed that Baerwald’s work came first, with Löfgren’s earlier seemingly lost forever.
Finally, in 1983, a copy of Löfgren’s paper was located in Czechoslovakia, revealing that it had been published three years before Baerwald’s. Still, to this day, most people refer to Löfgren A alignment as Baerwald and to Löfgren B as simply Löfgren.
In the decades following Löfgren and Baerwald, several others analyzed the problem and published papers, but most simply came to conclusions that mirrored Löfgren’s. Notably, J.K. Stevenson in 1966, and D.D. Brakemeier (UNI-DIN) in 2010, used fresh thinking that took into account the differences between the requirements for playing a mono shellac standard groove 78 in 1938, and a modern stereo vinyl LP.
What if we took all this scholarly study and analysis and simply tossed it out of the window? On some level, that’s the thinking behind the ViV Lab Rigid Float tonearm.
ViV Laboratory Rigid Float 9ha Tonearm
In https://www.stereophile.com/content/spin-doctor-5-vertere-dg-1s-record-player-playing-7-records-right-way”>Spin Doctor #5, I discussed how turntable and tonearm designers normally fall into one of two camps: the obsessive machinists who take a conventional design approach and execute it to perfection, and the deep thinkers who reject convention, preferring to write their own rules. Well if there ever was a deep-thinking designer, it is Koichiro Akimoto, the founder of ViV Laboratory (footnote 2).
After creating ViV in 2008, Akimoto took an idea that had gained some traction among Japanese audiophiles—the pure straight tonearm mentioned by Carr in that YouTube video—then added a few of his own design twists. I first became aware of the pure straight approach about 30 years ago when I was installing a cartridge for a Japanese audiophile here in New York City. My job was to install a new cartridge on his SME Series V tonearm in the conventional way, but I couldn’t help noticing a second tonearm on the back of the turntable with a Koetsu cartridge on it, with no offset angle. He explained that eliminating the offset angle eliminated the need for antiskating compensation, albeit at the cost of higher tracking-angle error. His reasoning was that the skating force generated by the offset angle, and the antiskating force applied by the arm to oppose it, did more to degrade the sound than the straight arm’s increased tracking angle error did to increase it. He played it for me, and it sounded good, but my mind was too deeply rooted in convention to contemplate this as a good idea.
Antiskating is a topic that seems to generate a lot of misinformation from people who really should know better, from “it really isn’t important” to “it’s a centripetal and/or centrifugal force” to “you need more antiskating at the end of the side than at the start.” All these statements are just plain wrong, but the truth isn’t very straightforward either.
In the real world, the perfect antiskating force is a constantly moving target, which fluctuates with the modulation level of the record groove, the position of the stylus on the record, the vertical tracking force, and the stylus profile of the cartridge. The so-called perfect setting is just the best compromise, taking all of these variables into account and balancing them out over time. At any given moment, the amount of antiskating force being applied is invariably wrong, so the ViV Labs arm simply gets rid of the skating force by eliminating the offset angle and making the arm straight.
Footnote 1: See youtu.be/fQeut0__a_4?si=GxkXijJXR36Ftvdw.
Footnote 2: ViV Laboratory, 5-10-16 Imaizumidai Kamakura Kanagawa 247-0053 Japan. Email: [email protected] Tel: +81 467-67-4495. USA importer: Sierra Sound, PO Box 510, Wilton, CA 95693. Email: [email protected] Web: sierrasound.net
NEXT: Page 2 »
ARTICLE CONTENTS
Page 1
Page 2