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? 

drbarney1

Showing 7 responses by lewm

Mijostyn brings up the LT and the 5G pretty much EVERY time the Viv is mentioned. I have no argument; those may be superior to the Viv, but that’s not the point. As to the skating force generated by the Viv: it’s always going to be proportional to TAE. So at the outer grooves it may be 10 degrees, worst case, gradually decreasing to zero skating at the single null point where also the direction of the skating force changes by 180 degrees and again reaches a negative maxima at the innermost grooves. A graph of the magnitude of the skating force is a near straight line passing through zero. Thus I would argue the Viv is much gentler than a classic overhung tonearm in terms of aberrant stylus wear. And it’s not a “brave” act to own and use the Viv, at all.

Jason, you say you wouldn’t use the Viv because it violates well established design principles, and that’s fine. But you go on to say you own two pivoted overhung tonearms with headshell offset, which in and of itself dramatically enhances skating force, each of which lacks AS, and you use them happily. Leaving aside the fact brought up by viridian that you are likely wrong in assuming one of those arms lacks AS, can you see the inconsistency in your decision making? 

IMHO, neither proposition is true. The distortions of different devices in the signal path are not necessarily additive, nor are they necessarily complementary. And if we’re talking about the Viv Float, it’s my impression as an owner that it introduces less audible distortion than my many conventional overhung tonearms.

In fairness to Pindac, I do not think English is his first language, although he has never said as much.  My guess is German.

Thanks for referencing those threads, Dogberry. I read the Audiokharma thread today. Boy, some of those guys go off less than half cocked. It would be exhausting to try to correct all the misstatements.

Pindac, are you saying that Stax and Micro Seiki once produced underhung tonearms with zero headshell off set? If so, that’s interesting. 

There’s a thread on the Viv Float tonearm. I suggest you review it. You are neglecting to mention that such tonearms are mounted so the stylus underhangs the spindle, as is the case for all of the commercially available tonearms that have zero headshell offset. Finally, such tonearms DO generate a skating force except where the cantilever is tangent to the groove; it’s just much less than for conventional pivoted overhung tonearms. I think it’s specious to analogize the HD of your SET with the tracking angle error of an underhung tonearm in the first place. I own a Viv Float, and I like it very much.