UNI-DIN vs Loefgren B DIN

abeidrov

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I’ve recently bought Smartractor and redid my cartridge setup using the UNI-DIN curve. I like what I hear, it is definitely an improvement and has been confirmed by better Analog Magik numbers. I then found an old article in the Stereophile, where UNI-DIN was compared Loefgren B. According to the article, Loefgren B curve produces lower distortion numbers over the better part of a record. I then read that the null points, used in the article for the UNI-DIN curve, were not correctly stated, and that led to wrong conclusions. What do you think? Shall I try Loefgren B alignment? Could you hear a difference between different alignment curves?

Thanks in advance!
 

DasguteOhr

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the best way to measure your records from your collection where the groove ends most time inside. then determines the curve and the inner zero point where you have the least distortion on the inside.;)
Inside importanter then outside you see in the graph.
1114UNI.jpg
 
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abeidrov

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This is the picture from that article. Are you saying that UNI-DIN is better as it has less distortion on the inside?
 

DasguteOhr

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I have found with random samples in my records that most of them end between 68mm and 80mm. that's why I chose Löfgren B.
20210209_075102.jpg
 
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tima

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Are you saying that UNI-DIN is better as it has less distortion on the inside?

It's more an issue of where do you want your distortion. UNI-DIN can be better on some classical music that has greater 4th movement dynamic constrast that is toward the end of a side.


Other discussions on UNI-DIN are available through WBF's search function.
 
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abeidrov

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Thank you, Tima and Stephan. I listen mostly to jazz and some classical music. I guess Loefgren B would be a good choice in my case. What is a difference between DIN and IEC versions and which one I should try?
 
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DasguteOhr

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it defines the maximum width of the grooves on the disc. DIN goes 57.5 mm inside radius to 146.05mm outside radius. ICE goes from 60.325mm inside radius to 146.05mm outside radius.
With the DIN calculation, the inner zero point moves inwards by 2-3mm, the outer moves too forgotten
Pic1DIN/ Pic 2 ICE zoom in to see it better 20210223_191044.jpg 20210223_191108.jpg
 
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KlausR.

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I then found an old article in the Stereophile, where UNI-DIN was compared Loefgren B. According to the article, Loefgren B curve produces lower distortion numbers over the better part of a record. I then read that the null points, used in the article for the UNI-DIN curve, were not correctly stated, and that led to wrong conclusions. What do you think?

1. I took part in listening tests to determine the tracking angle error where distortion starts to be audible. The results are published in an AES paper:


It was found that the tracking angle error has to be almost 12 degrees before distortion is audible. With correctly aligned cartridges the error is about 2 degrees, so far below perception threshold. Feel free to contact me for a copy of the paper.

2. Tone arms are designed with a particular alignment in mind, i.e. for a particular set of inner and outer groove radii, which results in a particular combination of effective length and offset angle. For that offset angle the (horizontal) axis of the vertical arm bearing is perpendicular on the line coinciding with the direction of the offset angle, on record warps the cartridge moves up and down only. If you now choose a different alignment you get a different offset angle, these two lines are hence no longer at right angles, which means that the cartridge moves up and down AND rotates about its longitudinal axis, so that the stylus is no longer vertical in the groove (when viewed from the front = azimuth), which results in changes in channel crosstalk and changes in imaging.

Klaus
 
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DasguteOhr

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use a highly dynamic female voice, try both curves and you will hear what you like better. I always use this lp and this song to set the pickup. you can hear immediately whether everything is correct or not. if this song plays cleanly it also promises to be good with any music.;)
try to get the limited edition, this is one of the records I would take to the island.
20210209_075449.jpg
 
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abeidrov

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2. Tone arms are designed with a particular alignment in mind, i.e. for a particular set of inner and outer groove radii, which results in a particular combination of effective length and offset angle. For that offset angle the (horizontal) axis of the vertical arm bearing is perpendicular on the line coinciding with the direction of the offset angle, on record warps the cartridge moves up and down only. If you now choose a different alignment you get a different offset angle, these two lines are hence no longer at right angles, which means that the cartridge moves up and down AND rotates about its longitudinal axis, so that the stylus is no longer vertical in the groove (when viewed from the front = azimuth), which results in changes in channel crosstalk and changes in imaging.

Klaus
Interesting point from Klaus here. I checked the null and inner groove points of Kuzma protractor and they correspond to Loefgren A IEC curve. Do you guys agree with Klaus? If true, any other curve should in theory produce inferior results. I wonder, which curves other Kuzma 4P owners use. Probably should post this question on the 4P thread.
 

KlausR.

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Interesting point from Klaus here. I checked the null and inner groove points of Kuzma protractor and they correspond to Loefgren A IEC curve. Do you guys agree with Klaus? If true, any other curve should in theory produce inferior results.

1. Different alignments will produce different amounts of distortion, but in view of the high tracking error necessary to hear distortion at all, the question of inferior or superior alignment is an academic one, in my humble opinion.
2. By the same token, the fact that the cartridge rotates about its axis on record warps thus producing azimuth variations is, in my opinion, also of academic interest, I just wanted to direct the attention to this issue.

Klaus
 

Solypsa

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1. Different alignments will produce different amounts of distortion, but in view of the high tracking error necessary to hear distortion at all, the question of inferior or superior alignment is an academic one, in my humble opinion.
2. By the same token, the fact that the cartridge rotates about its axis on record warps thus producing azimuth variations is, in my opinion, also of academic interest, I just wanted to direct the attention to this issue.

Klaus
Do you have a hierarchy of importance for the various aspects of cartridge alignment resulting from your studies and experiences?
 

tima

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Interesting point from Klaus here. I checked the null and inner groove points of Kuzma protractor and they correspond to Loefgren A IEC curve. Do you guys agree with Klaus? If true, any other curve should in theory produce inferior results. I wonder, which curves other Kuzma 4P owners use. Probably should post this question on the 4P thread.

My understanding is that IEC Baerwald/Löfgren A provides the lowest maximum distortion and v. good average distortion whereas UNI-DIN offers lowest maximum distortion in last two-thirds of the groove.

Attached is a Dieter Brakemeier paper (uni-din-2015.pdf) that offers his take on the UNI-DIN alignment curve.

Another interesting article in Stereophile by Keith Horward
Arc Angles: Optimizing Tonearm Geometry

"In all that has gone before, we have assumed that the Löfgren-Baerwald approach of minimizing the maximum LTE [Linear Tracking Error] distortion across the modulated extent of the groove is indeed the optimal one. But there is good reason to suppose that it isn't, because lateral-tracking-error distortion is only one form of distortion afflicting vinyl-disc replay. Another source of distortion is tracing error, caused by the replay stylus being unable to follow the same path through the groove as the cutting stylus. In large part this is a function of the shape of the replay stylus, and depends critically on groove curvature. Because of this, tracing distortion worsens toward the end of a record side, as the waveform cut into the disc bunches up."
 

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DasguteOhr

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as long as the stylus tip follows the arc line over the entire length of the lp, there is no problem. I love the printed stencils they show you immediately if you can use it.
there should be toarms that are not suitable for different curves. I had over 20 tonearms, never one was there where it didn't work.
I can't say whether that was the Optium, but I enjoyed the music with everyone. Do it and hear it.
20210224_184515.jpg
 
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Klaus is correct. Changes in zenith error impact other sonically important parameters when navigating warps - just as raising/lowering a tonearm changes overhang and so on. The tonearm/cartridge/record groove relationship is a multivariate environment. What we need to sort out for ourselves is, what changes are worth worrying about? The answer often depends upon your stylus profile, but sometimes statistical analysis will help too.

There is nothing wrong with Baerwald, Loefgren B, Stevenson or UNI-DIN. They are each simply efforts to determine where you want to apportion your tracing distortions. I think it is more important to make a decision on your innermost and outermost groove radii than to choose a single alignment scheme. I've done a 1,000 plus record measurement analysis (see "Tracing Distortion, Angular Error & Innermost Grooves" HERE) and my data shows that exceedingly few of my records go less than the IEC standard of 60.325mm radius.

% Incidence of Innermost Groove less than 60mm - 1950 and later pressings
Classical 5.2%
Rock 7.8%
Jazz 5.0%

I decided that I wasn't interested in increasing tracing distortion for ALL of my records to benefit the last couple minutes of play time on a tiny percentage of my records. This decision was solidified when I heard a comparison that Fremer did for me of the SAT tonearm and a linear tracking tonearm on a track that went to 56mm radius with an orchestral climax. The SAT tonearm uses an innermost groove assumption of 75mm, which is FAR away from the statistically significant figure I found in my record set for records made after 1990 of 68mm. As Klaus correctly points out, the tracing distortion at the inner portion of the record gets worse FASTER as it moves inward than it does anywhere else on the record. The SAT soundstaging collapsed the closer it got to the end of the record. High frequencies weren't nearly as extended and delicious as they were at the center of the playing area and things sounded more "SET"-like (I'm sure due to the higher second order harmonics resulting from the phase error on signals coming from the center of the two speakers). Imaging suffered a bit too, but it was still certainly a high-end experience. The net result was, which arm you liked better depended upon where you were playing it on the record surface!

I use an industrial microscope to view the contact edges of the stylus and inspect their angular relationship to the cantilever. I regularly see more than 2 degrees zenith error - even on the most expensive cartridges. I have the prototyped WallyZenith that I can then use to compensate for this zenith error. I have blind tested others and they use the same description I have come up with for the difference between corrected and uncorrected zenith: improvement in soundstage depth and width, increased imaging locational specificity and a generally "cleaner" upper midrange/high frequency experience.

With that said, I look forward to reading the AES paper that Klaus was involved in that determined error needed to get up to 12 degrees before it was audible. I certainly would agree that it would need to be that high before IM distortion (sounds like "breakup") was audible, but one can calculate that a "mere" 2 degrees of zenith error causes phase distortion on a 10kHz signal on a 33rpm record at the inner null point (Loefgren B) to be just under 3%. This causes harmonic and IM distortion of its own, but the IM distortion would be absolutely negligible. Harmonic distortion would not be. So, what was Klaus and company listening for? Changes in soundstaging, imaging and high frequency response? Did they use a severe stylus profile that had a minor radius less than 6 microns and a major radius over 40 microns? (I'm not suggestion there is anything magical about these figures. I'm just trying to illustrate the need for a severe profile to be able to hear the greatest difference.) Further, the math suggests that if dynamic SRA isn't spot-on FIRST, your efforts at discerning zenith error will be much tougher. Was this accounted for first? I look forward to finding out!

We have calculated that a 5 degree change in cantilever angle OFF of tangency at the null point causes a decrease of motor output in the neighborhood of 0.4%. It also causes some other IM distortions to increase as well. However, it is our opinion that the negative impacts at less than about 5 degrees are hardly worth worrying about. The cure is most certainly better than the disease inside of an acceptable tolerance. I aim to share the data behind this and the process for measuring zenith error that does not require an ultra-expensive microscope this year. I just need the microscope to validate the approach!
 
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Vienna

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it defines the maximum width of the grooves on the disc. DIN goes 57.5 mm inside radius to 146.05mm outside radius. ICE goes from 60.325mm inside radius to 146.05mm outside radius.
With the DIN calculation, the inner zero point moves inwards by 2-3mm, the outer moves too forgotten
DE5C2903-0608-44B6-9879-AED172D4B49B.jpeg F645078B-3CF1-40C4-9CE4-99CB4FF6F7A4.jpeg
Pic1DIN/ Pic 2 ICE zoom in to see it better View attachment 75296 View attachment 75297



Just noticed your background photo which I find disturbing. It reminds me one of the world‘s darkest times, during which billions suffered around the world. I don’t think that there is space in WBF for reichsadler symbols
 
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KlausR.

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Do you have a hierarchy of importance for the various aspects of cartridge alignment resulting from your studies and experiences?

When pushing my Genelec 1029 hard they start to distort, also those WAV files with audible distortion tell me how distortion sounds like.
On paper VTA error can be above threshold, but I have never heard anything that sounds like my distorting Genelecs or those WAV files when playing vinyl. In my book adjusting arm, cartridge, antiskating etc. according to the manufacturer's instructions does the job. No hierarchy of importance, to me all of this is more of academic interest rather than a real problem.

Klaus
 

DasguteOhr

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View attachment 75351 View attachment 75352




Just noticed your background photo which I find disturbing. It reminds me one of the world‘s darkest times, during which billions suffered around the world. I don’t think that there is space in WBF for reichsadler symbols
It is Rammstein Logo, i'm a Fan from the first hour..please don't interpret nazi shit purely
 
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KlausR.

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Another interesting article in Stereophile by Keith Horward
Arc Angles: Optimizing Tonearm Geometry

"Another source of distortion is tracing error, caused by the replay stylus being unable to follow the same path through the groove as the cutting stylus. In large part this is a function of the shape of the replay stylus, and depends critically on groove curvature. Because of this, tracing distortion worsens toward the end of a record side, as the waveform cut into the disc bunches up."

2nd order harmonic distortion in the inner grooves is about 2% (Fox 1963). Elastic deformation or the groove walls reduce these values
(Shiga 1966, Walton 1963). Perception thresholds for music are at 5-10% (Vanderkooy 2012).

For two-tone signals intermodulation distortion can have values of up to 40% in the inner grooves. Perception thresholds depend on music material and can reach 30% (Klippel 2001), so it may well be audible when playing vinyl. So far I did not hear anything strange in the inner part of the records.

Fox, “Tracing distortion – its cause and correction in stereodisk recording systems“, J. of the Audio Engineering Society 1963, p.294
Klippel, “Speaker auralization – subjective evaluation of nonlinear distortion”, AES preprint 5310 (2001)
Shiga, “Deformation distortion in disc records”, J. of the Audio Engineering Society 1966, p.208
Vanderkooy, „Another view of distortion perception“, Convention e-brief, 133rd convention of the Audio Engineering Society 2012
Walton, “Stylus mass and distortion”, Wireless World, April 1963, p.171

Klaus
 

tima

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2nd order harmonic distortion in the inner grooves is about 2% (Fox 1963). Elastic deformation or the groove walls reduce these values. ...

For two-tone signals intermodulation distortion can have values of up to 40% in the inner grooves. Perception thresholds depend on music material and can reach 30% (Klippel 2001), so it may well be audible when playing vinyl. So far I did not hear anything strange in the inner part of the records.

I find discussions of equalization curves somewhat interesting though they tend to be more about math and percentages than where they make a difference in terms of audible impact. Although I can respect a purist perspective, concern for inaudible distortion is not among my top cartridge alignment priorities. ;--)
 
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