What is you tonearm’s Maximum Distortion?


I’ve been playing around with different cartridge mounting, as a Grace arm the plinth of my Lenco cannot be mounted at the recommended pivot-to-spindle distance of 222mm (closest it can get is 225mm).


My best figures in theory seem to be:
Max. Tracking Error: 3.51 degrees
Max. Distortion: 1.21 %
Average RMS Distortion: 0.73 %

This is with: P-t-s 225mm; overhang 11mm; offset angle 19 degrees.

What are your figures for your setup?

fusian

If the numbers in the table published here by optimize are correct, two things pop out at me. First, the distortion figures are below 0.5% or equal to 0.5% in all cases. Given all the other distortions inherent to vinyl reproduction, does anyone here think he can hear the difference between 0.5% and 0.3% distortion? second, there is a dissociation between the magnitude of the tracking angle, error, or at least the maximum magnitude of the tracking angle error and distortion. Isn’t that interesting?

@lewm 

I am skeptical in using the calculated number for anything other than crude relative comparisons and find the plots to be much more telling of the relationships at hand. Below are the plots for the table @optimize posted above.  From looking at the table the Löf B sure looks appealing but the plots tell a different story if you are at all concerned about the last track on an original Blue Note.

 

for reference, here are the plots of the "low distortion parameter manipulated" alignment @rauliruegas posted.   When using a similar alignment I have found no point in listening to the last track or two of a side.

 

I have found that that the traditional 2X weighting factor is not representative of what I hear and that the weighting should be more like 4X. It seems you really need to cheat things to the inner groove closer to Stevenson to get a full side of high quality reproduction.  The last little tidbit is in general the numbers from these charts need to be multiplied by a factor of 5-10 to actually be representative of a real world measurement.

dave

@intactaudio : " If the parameter manipulation is kept hidden then there is another term for it.. "

Well, don’t tell to me but directly to the SAT designer. The OP P2S 225.. was asking for better numbers and the SAT ones gaves it.

" I have found no point in listening to the last track ... "" that's at least untrue because the higher distortion happens only with the LP that has groove modulations  up tp 60mm ( inner groove ) and even that you don't know if could be aware of it due that distortion goes in increment or decreasing groove to groove and ears goes accustom to. Not easy todetct it. Don try to " satanize " it: bad attitude.

 

Btw, have you an alignment with no trade-offs? and if you don’t have it then maybe it’s the rigth time that you do it because you critic and critic but don’t give nothing in change. Yes, you are free to post whatever you want but could be bette to leaft to critic the standard alignments and show a no trade of alignment that we all can name intactaudio. Show something and stop critic because that critics goes not against me because I did not any alignment I only use it as all audiophiles.

 

Which tonearm/cartridge alignment are you using?

 

R.

@rauliruegas 

Well, don’t tell to me but directly to the SAT designer.

I do not have an issue where mark sets his null points and I do not believe he would fudge the inner groove radius to 75mm in the calculations to avoid showing the sharp increase in distortion once you get closer than 75mm.

 The OP P2S 225.. was asking for better numbers and the SAT ones gaves it.

Sure... if you use a little harmless parameter manipulation and substantially shift away from a standard set of inner/outer groove numbers you can get vanishingly low numbers.  

" I have found no point in listening to the last track ... "" that's at least untrue because the higher distortion happens only with the LP that has groove modulations  up tp 60mm ( inner groove )

This is akin to saying that a silent groove has no distortion.   JR @wallytools makes a compelling argument and has collected data to support a trend in newer records and audiophile reissues to basically leaving the last track off each side to avoid the issues with the inner groove.  He offers a protractor with dual alignments to take this into account and makes it very clear what his goal is.  The key here is he gives all of the information and lets the end user select what best fits their listening style.  Taken to the extreme I could even see a second arm being added to a setup to allow for two different alignments to match JR's observations.

Btw, have you an alignment with no trade-offs?

Nobody does.  I actually believe that there are far too many variables that cannot be set accurately enough to get any specific alignment and simply getting two null points on the playable surface is no small task.  I want to be clear that I am not being critical of anyones alignment goal.  Everyone is allowed their own choice of compromise.  My problem is presenting manipulated numbers without disclosing the manipulation to justify someones choice.

 

dave

 

 

While I do hear some inner groove distortion sometimes, I am grateful to the last track for giving me a bit more listening time per side.