Will SME-V, etc benefit with non-stock alignment?


Hi,
it was suggested by some most knowledgeable member(s) on the subject of tone-arm alignment, to start a dedicated thread for 'fixed' stylus-to-pivot measurement arms.

To my knowledge those would be ALL SME arms, as well as ALL Linn arms -- there might be others.

The issue in particular is the method of overhang adjustment by moving the pivot (bearing arm post) a la SME to accommodate slight variations in cart design. Linn does not even offer that (go buy their cart(s), and get a life :-)

In the case of SME, the expected mounting hole to stylus tip distance being 3/8" or in more 'current metrics' 9.52 mm. (sorry not US quite as yet, i.e. both are valid)

If a cart has this design criteria, AS WELL AS! the cantilever in the centre AND STRAIGHT with respect to the cart body / mounting screw holes, and more recently all with a tapped thread in it, they would HIGHLY qualify, or?
BUT, how do you see, or know this is the case in the first place, when purchasing a cart?

Given ALL is right-on within spec. you then are 'stuck' with the alignment that, e.g. was decided (for you the purchaser).
As soon as you'd like to try some other alignment scheme, and there are some: Löfgren A (Baerwald) -- the SME point of view/choice, Löfgren B, Stevenson, plus in fact you may make up your own, that may be to your liking. BUT NOT with any of the 'fixed' type arms, since it'll play havoc with the arms intended alignment geometry. (Ask DerTonearm if you don't believe me. He'll give you the low-down right to the 100th of a millimetre!)

So far, so good. You can go to one of the expert template makers, state your case, give your cart and arm parameters and ask him to make on for you. 100$ ---- to 500$? somewhere around there.
BUT WICH alignment then please?!

One you think is better? The same? Why bother for the same?!
And IF different, will it actually work for you?

Well, if not, go spend some more 'greens' on the next try?

Of course if you are aware of these issue, you just go and buy another arm, right?
Hallo, but what about synergy for SME decks, ditto Linn decks and arms?

So hope to have made the point sufficiently clear. So let's see what we can learn, that we do NOT know as yet.
Could get interesting, I hope so.

But please keep it informative and don't come tell us a dentists drill will be a better choice than XYZ tonearm choice.
Thank you for reading,
Axel
axelwahl
Dear Axel: All of this alignment subject has its focus on " distortions ", which ones like us more or which ones make less harm. Of course which are the correct ones ( if exist a " correct " distortion. ).

Some of the vintage japanese arms does not conforms with Baerwald/Lofgren alignments. With some of those tonearms I set the cartridge alignment either with the builder specs and with the B/L ones.
I remember that in the Micro Seiki with the straight arm wands I prefer the tonearm builder specs that the B/L.

Other experience that I had ( by accident ) was with the FR 702 cartridge ( that for the ones that not know it comes with a dedicated headshell well you can't move rear/fwr the cartridge. ) that I buy many years ago and that I never mounted but like 6 years latter in the Lustre tonearm with out making any measures about stylus alignment and seat to listen and I remember that I was " shocked " with what I heard specially from midrange and up frequency range: it was almost glorious or at least that was what seems to me.
Was so impactant that I follow listening it with out take real notice of what was happening in the other side of the frequency range.

But the ears " wake up " and then notice that the low-mid bass were not totaly wrong but not good enough ( and this cartridge is very good in this range. ).
The distortions on both frequency range sides were different too and not acceptable in the LMB. If I remember ( I don't have mounted the Lustre right now ) the overhang was off by 5-6mm.
For those days I decided the absolute necessity to have some reference different recording tracks that can/could " tell " me what is " wrong or good " and where, obviously by ear only but this is a good way of training our brain/ears.

These and many oter experiences are learning and informative. One mm makes a difference in the alignment?, certainly yes; could we hear it? well you and your system quality performance are the best judge but the subject is not if we can hear it but that is incorrect.

Btw, nice to see that Lyra conforms according the IEC standards, I wonder why some other cartridge builders did not, anyone thinks that that IEC standard ( stylus to cartridge mount holes distance ) is not adequate/right or put " heavy " limitations to the cartridge builders on its designs? it needs a change?

J.Carr could you share your opinion about?, thank you in advance.

Regards and enjoy the music.
Raul.
According to the manufacturer, the Air Tight PC-1 stylus tip to center of mounting hole distance is "9.5mm, +/- 0.5mm." So, within the 1mm margin, that too seems to comply with the standard of 9.52mm. My actual cartridge measured 9.17mm which is the dimension I sent to Yip to make my protractor.
Raul, first we should ask if most cartridge manufacturers give much (if any) consideration to the IEC standard, or are even aware of it as a standard. Second, in reality it isn't easy to make each and every cartridge design accomodate a mounting hole to stylus pitch of 3/8 inch, and the greater the differences between a cartridge designer's individual designs, the harder it becomes to maintain 3/8 inch.

Some companies have exhibited little design variance in the cartridges that they have launched over a period of years, but others have shown major variances. I'm one of those who tends to make pretty radical changes between designs (or design generations), and I'd suggest that Dynavector is another such company.

I started out over 25 years ago with cartridge designs based on a classical-style single big magnet plus two polepiece (yoke) arrangement, but today my designs have evolved to two small magnets and no polepieces (with the exception of the Olympos, which is based on a platiron magnet that demands polepieces to function properly). The physical length occupied by a single big magnet plus two polepieces is _very_ different from two small magnets and no polepieces, and this is particularly true for magnets that prefer to be used long, such as alnicos and platirons. Such magnets require a long cartridge body (look at a Koetsu from the early 80s to see what I mean), and make it difficult to keep the mounting screwholes close enough to the stylus position. Now if I were to design something like the present Lyra designs but with a 1.7mm cantilever like a Dynavector DV17, I'd have the oppposite problem, and would need to integrate some kind of extender (like a stretched limousine) into the cartridge body to push the stylus sufficiently foward of the mounting screwholes.

The cartridge body outline (as seen from above) also turns out to be an important factor; cartridge bodies that remain square out to their corners are the most flexible because they give the designer maximum freedom to change the locations of the mounting screwholes without alteration to the other dimensions. In contrast, the signature Lyra body shape isn't well-suited for long magnet structures, because the angled corners midway along the cartridge body make it impossible to bring the mounting screwholes any farther forward.

IOW, 3/8 inch works well for some kinds of designs, but can be an ordeal and constraint for others ;-). I have been willing to adjust my designs to accomodate the 3/8 inch standard, but doing so has been tough going at times, and has definitely created a lot of extra work. If I didn't firmly believe in the importance of at least some kind of standard in cartridge dimensions, I'd likely disregard the IEC standard as being an unnecessary constraint on my design freedom.

When (not if) the 3/8 inch IEC standard is an impediment to cartridge design, it is understandable that some cartridge designers may choose to ignore it because it increases the design effort required and makes their work more difficult then they care to justify.

FWIW, based on engineering drawings that I have seen, even Ortofon doesn't always adhere to the IEC standard.

regards, jonathan carr
Jonathan :-)
you can cheer me up, thank you for your kind words.

If I talked about a difference, it is a small difference. The cart would not work properly if it was major --- but lo and behold MOST easily noticed when you swap a cart in an SME arm (fixed hole position and all). So I would have to guess and say, it was a ~ 0.5 mm variation. Looking at the two easily notice by a trained eye.

Now look at your quoted +/- 0.3 mm tollerance that takes care of a 0.6 mm variation alone (worst case), now I guess I'm making even MORE sense.

Good talking to you,
Axel
Fair enough, Axel. Thank you.

BTW, please note that applying tracking force to a cantilever will extend the stylus position forward by a small but noticeable amount. This is why Bob Graham's gauge uses a see-through crosshair piece that is weighted, to ensure that the stylus receives enough vertical force to shift it into the right location.

Ideally, Bob should add some kind of force or weight adjuster to his gauge so that it can be dialled in precisely for cartridges that have different tracking force requirements. Also there should be some type of height adjuster to enable the crosshair piece to remain in a horizontal state regardless of the cartridge height. But this, I suppose, belongs in a different thread - perhaps "Will Grahams, etc benefit with....." ;-)

regards, jonathan carr