Field coil dava cartridge

Maximum distortion difference between null points is only 0.1% if alignment accuracy is 100%: zero tolerance.

If one only has one eye this can be difficult to achieve

@rauliruegas 

 you are rigth, the 12" against a 10" EL tonearm in reality makes almost insignificant " improve " in tracking error. Using Löfgren A alignment IEC:

for someone who insists on 0.1dB riaa accuracy for hi-fi, you sure seem to have a very loose definition of the word "significant"

All those with 100% accuracy in the alignment but any tiny inaccuracy in the alignment makes that the 12" error gone way higher than in a short tonearm.

I believe you have gotten that backwards.  The shorter the arm, the quicker things get ugly with any misalignment.  This is assuming an advanced profile that has a very small window of "acceptable" angular error to begin with.

I guess this thread is about a cartridge with a conical profile but that doesn't change the general pattern of behavior.

and finally.....

 Maximum distortion difference between null points is only 0.1% if alignment accuracy is 100%: zero tolerance.

I do not believe the "weighted" distortion measurements derived from the formulas is actually representative of the sonic penalty angular mistracking error can cause.  It may serve as a great technical cudjoe to beat people with  but I generally trust arguments formulated from the listening chair rather than from behind a computer screen.

dave

@intactaudio 

Since you are one of the few here who interested in science and empirical measurement here is an interesting comment from Bruce Thigpen, designer of the ET2 linear tracker, whom has a degree in physics and audio engineering -

   The untold parameter of a pivoted tonearm: To minimize tracking
error, pivoted tonearms were lengthened with a bend in the wand, or by
mounting the stylus at an angle in the headshell. The frictional force
of the stylus in the groove wants to straighten out the bend or crawl up
the records inner groove wall. When using anti skating with a pivoted
tonearm to prevent inner groove wear, regardless of mass, pivoted
tonearms bend the stylus with an opposite side load force of between .1
and .2 grams per gram of tracking force, the tonearm shaft is being
twisted outward (as viewed from above) with this static load which goes
through the stylus suspension, but the percentage of creep on the inner
wall of the record groove actually varies with the passage loudness or %
groove modulation. So you are constantly bending the stylus while only
marginally solving the problem.

     With the ET-2 the side loads to accelerate the tonearm at .55hz
(33/13 RPM) are less than half of those values for an eccentricity of
.0312 inches (1/32 inch) and are a linear function of record
eccentricity. The cartridge cantilever suspension sees much lower loads.

     So as you add mass, this side load value of the ET-2 goes up
linearly, but is always less than using any pivoted tonearm with anti
skating.

    I hope this helps  - brucet

@mikelavigne 

You should read Bruce Thigpens comments above - as it relates to your CS Port linear tracking arm. Also I would recommend reading the ET2 manual on Bruces site - it has excellent information and testing data on linear trackers.

@dover

constant minor side load is not as big a deal as sudden heavy side load.

Bruce might have forgot to mention (i did not read your linked info) that linear trackers do also require precise set-up or they can put much more stress on the stylus at the point of initial contact with the groove....getting arm started; than a pivoted arm which swings free. the stylus transfers the whole weight of the arm assembly to the mounting point and so if the arm is not properly level and free to glide it will be harmful. linear trackers can be the cause of failure too. non air bearing linear trackers are more vulnerable to this.

i owned the Rockport Sirius II SE for 2 years, then the Rockport Sirius III for 8 years. now i’ve owned the CS Port for 4 years. so i do fully appreciate the positive aspects of that approach. but i also switched from the Rockport to the pivoted Durand Talea back in the day and overall preferred it at the time. now i own three pivoted arms (2--10.5" and 1-12") and they do their job in an exemplary manor too. more than one way to skin the cat and it’s all a matter of execution, not dogma. arms are just part of the equation.