Tonearm recommendation

Dear friends: """ What don’t you understand? Effective length = pivot to spindle (mounting distance) + overhang (spindle to stylus). If mounting distance remains constant, then effective length (L) must change with a different alignment. """

that’s a common misunderstood on cartridge/tonearm alignment set up that I had for many many years and that many of us still have.

When a tonearm designer/manufacturer begin with his design he choose the tonearm effective length not the pivot to spindle distance. He does not care on this distance because tell him nothing. In the other side knowing the tonearm effective lenght in his design all the other alignment/set up parameters comes trhough the choosed alignment calculations it does not matters if he choosed Baerwald, Löfgren B or Stevenson.

The designer choose only one alignment type not 2-3 of them and even if he choosed ( this never happens. ) 2-3 diferent alignmets the effective length stay the same because is the foundation of his design. As I said no designer choose pivot to spindle distance as foundation for his tonearm design, has no sense to do it.

In the example I posted here on a 10" tonearm ( effective length. ) all the main parameters/variables were diferent for Baerwald, Löfgren and Stevenson. Here I write again he calculations:

OVERHANG: B L S

16.224 16.681 13.43

Off.ANGLE: 21.586 21.586 19.912

Pivot-Spindle: 237.78 237.32 240.57


and the Null Points calculated are diferent too:

inner null p.: 65.998 70.285

outer null p.: 120.991 116.604

this NP. is where on each kind of alignment the tracking error and distortion is cero in a pivot tonearm and the foundation to have a graphic/diagram for the overall distortions through the LP surface recorded grooves.


The data input in the equations for any of those alignments are:

innermost groove distance, outermost groove distance ( here we can choose between standards as: DIN, IEC or we can choose a different values. ) and EFFECTIVE LENGTH ( the one and only choosed by the tonearm designer ).

Through those 3 data inputs the equations gives :

Overhang, offset angle, null points and pivot to spindle distance. These are the variables in those standard alignment types.


If for a more easy task we just change the overhang and offset angle with out change too the pivot to spindle distance what we have are higher distortions in ALL the recorded LP surface!!!

So we have to respect the equations in those white papers and do not do it the other way around as fleib suggest. Looks the same but it’s not and what any one of you can do it to confirm it is to make your own calculations where you will find out those higher distortions figures I’m talking about.

Btw, a friend of mine that I respect and who owns like me the Dynavector 505 told me that he prefers in his tonearm the Stevenson alignment recomended by the manufacturer when my self do not like S. alignment and prefer Löfgren.

If in that 505 we try to make the set up with Löfgren alignment with out change in the pivot to spindle distance then because the distortions goes higher we dislike what we hear. Maybe my Agoner friend just don’t change the tonearm mount position in his TT.

Many of us make changes in the overhang/offset angle with out any change in the pivot to spindle distance and is a mistake. I understand that we do or did not because we can’t make new drills in the plinth every time we make those kind of changes. Now, if we choose not to change the PtS distance we can do it but distortions are different, as I said in other posts we can manipulate the original equations and makes whatever we want it but this is not the subject here. I’m talking of be orthodox in that regard.


As I recomend to fleib maybe is time to read again the original Löfgren papers and not like fleib just posting with out read it and not only read it but understand it.

Now, maybe with some of you the differences on what I hear with some cartridges is because the alignment set up difference.

The message here is that we don’t need to change the alignment we have but to reset it and make again the set up with " cero tolerances ".
Accuracy is the critical main parameter we must care during the set up because minimal errors as 0.5mm ( overhang ) represent not only where the distortions will happen but that those distoritons goes higher too.

I think that Baerwald or Löfgren is more than enough the alignment we need.

The message to all toearm designers/manufacturers is that take their main responsability to give usthe accurate and user friendly JIGs to set up their each one tonearm design. Responsability that today almost all just don’t give the vital importance for we customers and music lover audiophiles.


Regards and enjoy the music,
R.

PS:  I'm sharing my opinion here to learn and not to achieve that " I have the reason and you are wrong ". Nothing like that far away from that sentence. I can be wrong and I would like to know  if really I'm wrong and if yes then I hope that any one of you be so kind to tell me in a wide explanation why I'm wrong. That's all, always I'm willing to learn and if necessary accept my mistakes. With out mistakes we just can't learn and grow up.

Thank's for your help and understanding.

Distortion analyzer should say measured.  Probably smoke and eyewash.

The reason some people find those zero offset arms sound good, is reduction of torsional forces on the cantilever. Do linear arms solve these problems? If and only if, they can maintain tangency at all times and otherwise behave as a proper tonearm Re: mass, friction, etc.

Fleib,
Don't you mean the other way round. If an arm has zero offset vertical bearings then there will be torsional force on the cantilever when the arm moves up and down. If the tonearm has offset vertical bearings that match the cartridge offset, then there will be no torsional force on the cantilever when the arm goes up and down, however there will be additional torsional force on the bearings with an increase in bearing friction in the vertical bearings.
Your comments on the Dynavector make sense, the arm comes with a jig for the cartridge which if followed the cartridge ends up dead straight in the headshell with the vertical bearings aligned. If Baerwald A is used in the Dynavector then the cartridge is offset from the vertical bearings and torsional force is introduced into the cantilever. This is probably not a good thing in such a short arm.