Tonearm recommendation

fleib, when you say "fancy Dennesen tonearm locator, just as all these alignment grid/pivot pointer protractors are based on the SoundTractor, only they're better." do you mean the others are more accurate than the Dennesen?  Or easier to use?  Something else?

I'm not at all familiar with the UNI and I've at least looked at a Feickert at audio shows.  But I've owned and used a metal Dennesen for nearly as long as Lew.  So long as the pivot point of the arm can be located I've had no reason to be disappointed with my cartridge set ups.  And yes, I'm satisfied with the Baerwald alignment.

If I'm out of date I'd appreciate being updated.

Dear friends: I hope this could be my last post in this controversial and misunderstanding critical/vital tonearm/cartridge set up.

"  Yes, the Loefgren calculations are correct. They are the basis of all the others. ", with the fleib " approval " here it is:

" Löfgren’s prime strategy is the ‘Löfgren A’ alignment which is based on adjusting the offset angle and overhang so as to minimise the weighted tracking error (WTE) and so minimise tracking distortion. "

The equation develpments to achieve those targets has three data input: outermost groove, innermost groove and effective length.

Löfgren and also tonearm designers/manufacturers does not care about P2S but primary the knowed/choosed effective length ( this is the first tonearm design parameter for nay designer. ) and second the offset angle and then overgang and at the end and  for reference to mount the pivoted tonearm design the difference between L and d gaves in automatic the P2S.

Baerwald, Bauer, Pisha, Stevenson and other gentlemans developed similar equations to Löfgren A ones. Stevenson developed two solutions, his B one similar to Löfgren and the A one that´s the one knowed as Stevenson ( the one used in Dynavector and other Japanese tonearms. ).

Stevenson used his original equations and in his A solution what he changed was one of the equations data inputs: instead of innermost groove distance he changed for an  inner null point to have at minimum ( last inner grooves mms. ) the distortion levels/tracking error in these last inner grooves with the trade off that all over the other LP recorded grooves the distortion is higher.

In all kind of alignments/solutions always exist trade-offs, there is no single kind of perfect alignment.

Now, if a tonearm manufacturer wants to change the original choosed tonearm effective length or wants to design a new tonearm with different effective length he will use the same equations and only makes the change to the new effective length data to know the new offset angle and overhang but as the begining he does not cares about the P2S for his design.
As a fact a manufacturer need to know the P2S distance for two main purposes: to build the tonearm mount JIG and information for his customers and that's all.

Whatever solution/alignment is choosed by a tonearm manufacturer the data inputs needs no changes and must be the ones stated by Löfgren and the others gentlemans but the Stevenson A solution.

So, to mantain the required distortion levels on each one of those alignments type everytime that efective length change the solution equations give us the changes in: offset angle, overhang and P2S.

In those old times ( 30's. ) Microsoft Excel tools did not exist and no spread calculators as the ones we have over the net that far away to really help us can puts several misunderstandings as the fleib/dover/lewm/Dynavector ones and many others, I made the same mistake for years Maybe in a dedicated thread I will disclose their common mistake in the mean time I hope that by it self they can find out the correct answer that's the Löfgren one.

Through several net calculators we can change the data inputs in the way we can imagine: we can stay with the same offset angle for different effctive lengths or we can stay with the same P2S for different effective lengths or change the innermost/outermost groove distance out of the IEC or DIN standards or any " crazy " choice but normally with out any real sound quality improvements but more of the time with higher distortions and a change in the LP surface where those distortions happens.
All these non-orthodox algebraic manipulations to the original equations are reallu useless for the customers/audiophiles.

I posted that the name of the game in a tonearm/cartridge set up is: ACCURACY and through the posts in this thread all were exposed about and why we don't need to look " for three foots of a cat knowing has four ".

IMHO we don't need Stevenson A or an special alignments for some kind of LPs , is futile 
What we need is that the Baerwald or what we choosed  be made it with ACCURACY/CERO TOLERANCE because a deviation of less than 0.5mm on overhang or 2° in offset angle or in P2S makes that distortions goes severly high against an accurate set up.

We audiophiles like to take out the tonearm manufacturers main responsabilities and own 4 or 10 different alignment protractors and we have " fun " making changes with out understand in deep what are invloved through each single change we do about and I think that we have to take seriously this vital cartridge/tonearm set up that in many ways define the quality sound level of our each one system.

My advise is: stop to play that game like a child with a new toy instead to play with only one alignmet solution toy and play it with ACCURACY.

If we are playing all those " games " with out accuracy what we are listening are only sound/music information with higher distortions, it does not matters that we are happy with those distortions.

In the mean time that the manufactuers of tonearms takes by it self the responsability to give us the ACCURATE and user friendly protractors to mount the tonearm and to mount the cartridge what we need is not a protractor with multiple options ( is useless. ) but one with single option ( example Baerwald. ) that be ACCURATE like the MINTLP that's dedicated to your specific TT/tonearm.

I can see here that some of you are proudly owners of several after market protractors of different prices, good you are but normally almost all of them are not good enough. In the other side ask your self: how many times each week or month do you need to change the kind of alignment ( for whatever reasons. ) in your tonearm/cartridge set up and WHY you need to do it? is usefull?

Remember that the distortion levels change in tiny increments/decrements at each recorded groove and no one of us can discern those distortion levels it does not matters the overall quality of the audio system we own.

Of course that the after market protractors builders tell us why we have to use diffeent kind of alignments and they take advantage of our each one misunderstood level.

Btw, from the last years the audio after market item market niche was and is growing up and maybe is better business than to market audio products and are all these audio products manufacturers whom permited the grow up and existence of all those after market items. Pity.


Regards and enjoy the music,
R.


dover, no I don't modified my 505 and the new set up is only 2mm ( around it ) on P2S and less than 1.5° on OA. The dyna specs are not accurate.
Never mind, has no critical importance your posts but a misunderstanding by your part. Please don't give any answer to this opinion.

Raul, It would be helpful if I can boil down your idea into one or two simple sentences.  Is it your thesis that one should standardize on one and only one geometry, Baerwald, because it offers the lowest average tracking distortion across the LP surface?  If you can respond "yes" or "no", that would be OK with me.  Thanks.

What I, and I think also Dover, wrote is that if the tonearm was not designed for Baerwald geometry (meaning essentially that the headshell offset angle is wrong for Baerwald, given that the tonearm is mounted according to manufacturer's recommended overhang or P2S or whatever), then one must twist the cartridge in the headshell to achieve Baerwald.  I found that this resulted in a distortion (Dynavector DV505) that was much more obvious and objectionable than any that I hear when I use the DV505 with recommended geometry, inferior though that may be by comparison to Baerwald.  Granted, one could move the pivot point around, or alter stylus overhang, so as to better accommodate Baerwald for a tonearm not designed for Baerwald, but that is very inconvenient at best, if not impossible in some cases.

Now it also seems you are saying that every protractor except maybe the Mint LP is an inferior toy.  That helps no one, except those who use the Mint LP.

fleib, thanks for the helpful response.

In fact I have used my Dennesen for the reverse process, to draw the arc to identify location for mounting an arm.

I also use a small Tensor light and hand held magnifier with the Dennesen when doing an alignment.  And I ignore the cartridge body and do all my sightings along the cantilever.  But I will check out linen magnifiers to see if one might be easier that what I use now (a small version of your standard Sherlock Holmes model).

And now that you mention it, I seem to recall the Feickert I saw did offer alignment options, but as stated, I'm happy with Baerwald.

Over the years I've owned a dB Systems protractor and those from various arm manufacturers but I really like the simplicity of the Dennesen.  And the results sound good to me and elicit complements on my system. ;^)