Dear Peterayer, agreed. When you know the stylus tip to mounting hole distance you can get a good geometry with new calculation based on the SME V's mounting distance. Thats where the MINT protactor and its specific individual calculation comes into place. |
Dear Raul, you asked:
"Dear friends: Anyone of you can corroborate what I posted here:
www.ispexperts.com/BaerwaldLof...
Dertonarm: where can we corroborate what you posted? "
Where to corroborate my postings on this topic ?
In every decent (high-school) book about geometry........... and in the AES chronicles (but those too do demand some basic knowledge and understanding of geometry and interelations).
Regards and enjoy the music...... |
Dear Axelwahl, dear Feathed, you should check and read (for inspiration...) the thread about "oldskool tonearms...." from last month. During this thread the problem of tonearm geometry was discussed in length. Inner groove distortion is either a problem of:
a) miss-alignment/-adjustment of tonearm (any of its parameters)
b) miss-alignment/-adjustment of cartridge (any of its parameters)
c) worn or damaged stylus
d)...there is no d)
If you hear clear and precisely that the sound is significantly better at the 2 zero-error points, than your set-up is NOT optimal (in fact - far from it).
Please do re-check your whole tonearm-cartridge set-up (for the sake of your record collection....) with a good (Denessen or similar) tonearm alignment tool. |
Dear Axelwahl, BTW - I know Dirk Sommer - and honestly, he is NOT into tonearm geometry at all (noone of the staff at Image-HiFi is really into tonearm geometry - they are all happy if they do NOT have to mess around with that ...). The tonearm/cartridge combination you are using can be - assumed that nothing is defect - adjusted to excellent and homogenous sonic results and no distortion at all.
Its a matter of skill, care and precision. |
Dear Jloveys, agreed. Bob Graham is one of the - very few... - who has done literally all his homework. His tonearms are - in the very sense of the word - "complete". With his clever pre-set-up alignment he provides a tool which will enable even the most inexperienced audiophile to get at least 90% of the posible optimum from his tonearm/cartridge-combination. All you need it that and the 100% precise spindle-bearing-mounting distance (he supplys a very nive tool for that too....) - then follow the manufacturers recommendations in terms of VTF of the given cartridge (during break-in close to the maximum recommended VTF...) and that will ensure that inner goove distortion and big sonic advantage at zero-error points won't haunt you at all.
High-end can be easy......... clever applied and precisely followed physics do help a lot. |
Dear Axelwahl, the TT's spindle to the tonearms pivot bearing point is NEVER variable in a pivot tonearm. It is the ONE single FIXED foundation of a given tonearms geometry. The distance of the tonearms pivot point to the center of the LP (= spindle of TT's bearing ) is NOT variable. The SME sliding mount is not meant to "variate" the mounting distnace nor to compensate for the fixed cartridge mounting holes. The SME V has a fixed mounting distance of 215.35 mm (SME does give this value in such detail because it is paramount for the whole tonearm geometry....).
Not taking this point as serious as it is means to skip the whole geometry alltogether and results in poor sonic performance and high distortion.
Please see here:
http://www.sme.ltd.uk/content/Series-V-1330.shtml |
Dear Axel, we do talk about the same thing.
However - there is a huge missinterpretation by several SME V owners.
On the whole sliding distance of the SME mount - some 25 - 40 mm - there is ONLY ONE POINT where the spindle - pivot bearing distance (=mounting distance) is exactly the 215.35 mm SME does specify.
The distance is always the same on a circle around a given fixed point (here: the spindle). The SME slide does not feature a circle segment, but a linear one.
I guess the point is clear now - isn't it??
The SME-mount was introduced in the 1950ies to allow precise alignment of the mounting distance even when the drilling of the wooden armboard was inprecise. The fact that the SME V does feature fixed cartridge mounting holes have been critiszed from the day of its introduction.
It is simply a big mistake in its design. If the horizontal distance mounting holes to stylus on all cartridges would be the same (as it should, but is not...) , then SME would be right. But in real world, the SME does not allow adjustment of overhang........ with a given cartridge you either get it right by simple luck - or you doesn't.
You can not adjust it.
Unfortunately cartridge designers do not stricly design there cartridges with a standardized distance mounting holes to stylus.
Again - yes, there is no overhang adjustment possible with the SME V......
Sorry - SME's fault.....
I know a few SME V owners who do indeed have modified their SME V so that now they do feature oblonged holes to mount the cartridge.
They can adjust the overhang now.
With a stock SME V you simply CANNOT adjust the overhang.
If you try by using the SME slide, your whole geometry goes nowehere.
Thus the SME V does limit your selection of useable cartridges quite a bit...... |
Honestly, - what I have described is not my opinion, but simply the physical fact and the geometry. You do not have to "believe" me or the "arguments" made. Please read the papers published in Audio Engineering Society Jopurnal during the 1950ies to 1990ies about tonearm geometry - these are the standards of tonearm geometry - nothing else. SME hoped that all cartridge designers would agree to a standard in horizontal distance between the mounting holes and teh stylus. If all cartridges would feature the very same distance there, everything would be fine.
They did not and still do not.
So any tonearm unable to adjust the overhang (with the spindle - bearing pivot distance (=mounting distance) of course a fixed value) has a big problem.
Please make a drawing on a sheet of paper - the visual manifestation will help to illustrate and clarify the point. It is impossible to adjust overhang by moving the whole tonearm !! Overhang is a value that DEPENDS on the geometry of the given tonearm !!! The geometry of ANY pivot tonearm has one foundation: the spindle-bearing distance (= mounting distance).
The whole calculation of its geometry roots in this value.
If you move the pivot of the bearing away from the specified value as given by the designer, the whole geometry of your tonearm is gone!
We are talking plain, 2-dimensional geometry only here - this is nothing that can be discussed in any way. It is fixed since about 2500 years when its foundations were displayed and described in ancient Greece (well, - and before in Egypt....).
Its not whether I am right or wrong - it is the physical and geometrical fact.
SME simply made a mistake in taking a specific value for granted (the distance between the mounting holes and the stylus being the same in all cartridges). |
Dear Axelwahl,
I will keep it as short as possible.
1) it is possible to adjust teh overhang by moving the whole tonearm. But if you do so, your specified mounting distance is gone unless you move your tonearm on a circle segment always amintaining the very same spindle-bearing distance. This is a simple geometric fact. A sheet of paper and a pair of dividers will nicely illustrate the point.
2) The geometry depends on the mounting distance of the tonearm as the first NON-variable parameter of the basic calculation. If you adjust the overhang (which depends on the spindle-bearing distance founded geometry...) by altering the basic parameter, the overhang you just adjusted to is no longer the overhang you tried to align to..... because you moved the tonearm.....
3) the overhang DEPENDS on the mounting distance - not vice versa....
4) It is a BIG difference, whether you adjust the overhang with oblonged holes in the headshell (because the mounting distance remains, as you do not move the tonearm.... only the stylus) or by moving the tonearm. To adjust the overhang is a movement RELATIVE to the FIXED tonearm. You move the stylus relative to the bearing pivot and the spindle - not the tonearm!!
The spindle and the pivot bearing are FIXED PARAMETERS because their distance is the FOUNDATION of your tonearms geometry.
You can choose different zero-error points on the arc of the tonearm/stylus movement over the LP's surface and by doing so you can - for instance - bring the 2nd zero-error point closer to the inner grooves.
However - the basic geometry of your tonearm remains the same.
The nice alignment tool provided with every Graham tonearm gives a nice idea. You can align your cartridge to either Loefgren or Baerwald geometry, but you do so without moving the Grahams base - you align at the headshell only.........
The groove modulations in any LP are VERY small. A "bit" derivation results in HUGE errors in de-modulating because the VERY TINY polished areas of your stylus are no longer aligned.
Thats the difference in playback between distortion-free High-end and "so so" sound with inner groove distortion.
1-2 mm........ well, your polished flanks on the stylus are 2-8 µm (thats 1000th of a millimeter).....
1-2 mm here are 10 - 20 miles in real world playback.
So - in metapher, you are "still in the same county or district, but you are no longer in the same block, you are in a different part of the city - and you will never find the address the Lady gave you to meet her...."
In analog playback all quality starts here - at the demodulation in the grooves of the LP. If you do not precisely align 100% here - you will have an endless (and futile...) journey trying to fix problems in your system which you never can locate or solve. |
Dear Axelwahl, the pivot bearing to spindle distance does NOT determine were your zero-error points are located. Again - see the Graham alignment tool with 2 options to adjust to either Baerwald or Loefgren - the zero-errors are on different points on the arc, but the spindle-bearing pivot distance is of course the very same on both, as the base of the Graham is not moved, but the adjustment takes place at the headshell ONLY.
I guess the point is clear now - isn't it? |
Dear Axelwahl, good to learn your mounting distance is fine. If you had checked that earlier, we could have spared some time and space here...
Anyway - if you still have inner groove distortion when the tonearm geometry itself is fine, then this can be related to several points:
a) lateral azimuth of the cartridge/stylus
b) horizontal azimuth of the cartridge/stylus
c) antiskating
d) 2nd zero-error point already long passed when you reached the inner grooves (the SME uses an IEC-standard when calculating the zero-error-points. The 2nd point is pretty close to the 1st and in the inner grooves you are close to the maximum error - why this IEC-standard was used and favoured by SME and Ortofon was explained in the "Prices for Oldskool tonearms"-thread. It has to do with the new way to master and cut LPs in the early 1980ies.
a) and b) can hardly be altered in the SME V, but you can try - usually there is a small degree of free movement. Both do have direct impact of the position of the stylus contact area to the groove walls.
c) antiskating or skating force as the source of distortion will apply, when the distortion is pre-dominant in one channel only. |
Dear Axelwahl, this way this is leading nowhere in an endless circle.
It would really make sense if you browse through Google and download the original papers by Baerwald and Loefgren about tonearm geometry and the complex interrelations. Reading them will answer 98% of all your questions and will set the whole theme in the right context.
Alternatively ou may send me a direct email (via Audiogon - just click on my alias dertonarm ) with your telephone number and I will call you up and describe the point in both our mother language. So far you still do missunderstand a few points in tonearm set-up and I will gladly clarify them in a short telephone call.
Greetings from a lakeside with view to the northern Alps (Zugspitze),
dertonarm |
Dear Axelwahl, all you are asking is explained during the course of the thread mentioned. You either have to keep on reading all through that thread or send me a direct email.
This is too much, to repeat all that was written in March during that sometimes very hot discussion in that thread. |
Hi Axelwahl, you should consider the MINT LP tractor. If you settle for one specific cartridge right now, it is well worth the investment - especially with a SME V. It does provide very good results and is easy and fast to use. |
Dear all, to my knowledge the 9" and 12" denomination was introduced by SME with their original 3009 and 3012 tonearms (hence the names...3009 and 3012). Ever since then 9" and 12" is used to describe tonearms which do have an effective length around the 9" or 12" figure.
But they all do differ in their effective length - some are very close, hardly any is exactly the same as another.
Take a few 12" tonearms as example:
- SME 3012 - 307,34 mm
- MAX-282 - 282 mm
- FR-66s - 307 mm
- SAEC-506/30 - 295 mm
these are all named 12"-tonearms. 12" is 304.8 mm - so none of the above mentioned tonearms is really 12" in effective length.
Only the SME 3012 and the FR-66s are close to that measure. Same for the 9" SME 3009 which is VERY close with its 229 mm (the later 3009R has 231,80 mm.......).
Well - we can alter the effective length of any given pivot tonearm.
And we do.
We can do so easy and - in a certain and narrow range. We do this when we adjust/change overhang (and in the same procedure the related offset...) to achive for instance Baerwald or Loefgren based geometry. We had that topic already back in the thread about the "Oldskool tonearms".
Take again the Graham alignment tool.......... here you have a very good and clear example.
The base (= mounting distance) isn't moved at all. The change is done at the headshell by different overhang and offset.
The mounting distance is still fixed. You change overhang and offset to adjust to different zero-error points - not the mounting distance (at least..... you shouldn't....) - not the mounting distance P-S.
The mounting distance is the 1st and basic parameter of the calculation of any pivot bearing tonearm. |
Dear Rauliruegas, all I did was displaying the geometrical facts. I don't know why you are so mad about this and why you have so many problems accepting these technical parameters which were and are used in analog playback in the past 6 decades.
Again - take the Graham and your comparism between Loefgren / Baerwald:
With the supplied Graham alignment tool you do adjust for either Baerwald or Loefgren. You do so with the detached armwand only and you do all adjustment at the headshell only. When the adjustment to either geometry is done,you fix the armwand to the - never moved... - armbase. So it is quite obvious, that the spindle-bearing pivot (=mounting) distance is not moved.
I think the big missunderstanding is that there are always 2 (TWO) geometrical calculations in tonearm playback.
a) the geometrical calculation of the pivot tonearm itself
b) the calculation of the arc with its 2 zero-error points.
b) can always bealtered by changing overhang and offset.
In doing so, we change the effective length and set the positons of the 2 zero-error points to different degrees on the arc and further apart or closer together to acommodate to LPs with longer run-out-grooves (IEC standard 1983) . The mounting distance remains the same.
Lets have a look at the tonearms you are using in your home system:
SAEC WE-8000, MAX-282, GST-801, AC-4400, IT-407, AR-1M - all these toenarms do not offer any possibility to change the mounting distance. Their bases are fixed. But you can nevertheless adjust tehir geometry to Loefgren/Baerwald or any other other arc-geometry - WITHOUT changing the mounting distance at all.
Same for Dynavector, EMT, Ortofon, Koetsu - the huge majority of tonearms does not feature a slide mounting base....... once you have drilled the mounting hole - thats it.
You can not change the mounting distance on these at all!
They are all fixed.
For good reason.
The sliding mount of the SME does lead into the erratic idea that mounting distance can be changed freely. This is a geometrical error.
Bob Graham used the SME slide mount because that mount was widely available and because it enables the user to adjust the mounting distance precisely to the manufacturers specs. |
Dear Raul, the Dennes paper is very good indeed. Its a great classic since 2 decades. However - it too does only deal with the "2nd" geometry. Baerwald, Loefgren, bauer, Stevenson etc. - this is all about the geometry of the stylus in a given tonearm. Thats why the mounting distance is not taken into consideration at all - it is not needed in those calculations and it taken as any fixed parameter.
These calculations do not deal with a specific tonearm - they deal with the ALIGNMENT OF A STYLUS in an - already mounted to its individual geometry - given tonearm. All these papers do not deal with the basic geometry of the given tonearm.
Maybe we have a big missunderstanding here - I mean there is:
A) a basic geometry of the tonearm itself. This is an individual geometry of a given tonearm.
B) then there is the geometry of the stylus in a GIVEN (= its individual geometry already fullfilled) tonearm.
This - I would like to call it "individual" or "secondary" - geometry is kind of universal. It applies to ALL cartridges and have several options to calculate and align the tracking arc and its zero-error points and maxima and minima derivations from the arc. |
Dear Raul, a very interesting point.
You are right - the effective mass does indeed increase when you move the cartridge away from the pivot/bearing. The position of a given cartridge does have some influence on the resonance frequency. Whether it is enough to really contribute to the sound itself has to be explored. The effective moving mass of a pivot tonearm is also (sometimes very drastic...) affected by the weight of the cartridges body (Koetsu's stone bodies.....) and/or the weight of the headshell (lightweight Orsonic AV-11 vs. FR S/3 for instance - a difference of over 21 grams !!!).
Both these units do "sit" at the very end of the "balance gauge" and thus do contribute very strongly to the effective moving mass.
Very interesting point indeed!
This too is one of thereasons why the torsion resistance of a tonearm is so important - the further away the cartridge is, the higher its influence on the mechanic resonance behaviour of the tonearm. |
Dear Peter,
we have to mate either tonearm with a cartridge with perfectly suitable compliance, - if done so, there will be no trade off in moving mass vs. effective length.
Given an ideal match with the compliance of the cartridge, we can assume almost identical conditions in terms of resonance frequency.
So the geometrical advantages of the 12"-tonearm will prevail.
The sonic advantages will be especially noteable on well recorded opera with comperatively large soundstage.
The sonic presentation of the soundstage will be much more stable and the positions of the various singers and their movements on stage will be more precise.
So - as I see it - there is no trade off between moving mass and geometrical advantage.
I do not want to call again and alone the example of the FR-tonearms (the FR-66 will always beat the FR-64s with any given FR-7 system), so lets go to Ortofon instead:
- do mount a SPU in a 9" Ortofon and in a 12" Ortofon tonearm. Both do have effective moving mass together with the SPU which will result in resonance frequency very close to each other (but it will be lower in the 12" Ortofon). Given exact mount and alignment to the same geometry (Baerwald, Loefgren, Bauer, Stevenson - no matter which, as long as its the same for both), the 12" will prevail in terms of size of soundstage presented, ease of tone and naturalness.
All these features are related to lesser derivation from the zero-error-curve - because the 12" tonearm does come closer to the theoretical ideal tangential. |
Dear All, I do agree with Raul on most of what he said in his last post.
However - let me put it in a few "axioms":
1) offset, overhang and effective length do relate to each other and CAN be CHANGED WITHOUT changing the PIVOT-BEARING DISTANCE. Offset, overhang and effective length do change when you align to a different arc-calculation (say - change from Baerwald to Loefgren).
2) If you change the pivot-bearing distance you change the WHOLE GEOMETRY of the given tonearm.
3) you get the very best results with the recommended pivot-bearing (= mounting distance as specified by the manufacturer, because the whole geometry of the given tonearm builds on that one parameter.
4) whether you choose Loefgren, Bauer, Baerwald, Stevenson or whatever calculation for the alignment of the stylus (and these calculations are onyl aiming at the position of the stylus - not at the position of the tonearm !!) is INDEPENDENT from the geometry of the tonearm itself. These alignments can all be done at the headshell alone without moving the base (and thus the pivot-bearing distance). And they should be done without moving the base because that way you can be sure that the basic geometry of your given tonearm is as specified by the manufacturer.
I think we must clearly put a line here between the geometry of the tonearm WITHOUT a cartridge. This is the basic geometry of teh tonearm itself.
Then there is teh geometry of the stylus in a given tonearm. This is step 2. Here we have the option to align to whatever calculation does fit our needs best (for instance more modern pressings with long run-out-grooves or pressings from the early 1960ies with the inner grooves running close to the label - these need different alignments - one rather Baerwald - one rather IEC). Here we lay the position of the 2 zero-error points and the maxima and minima derivation. This 2nd alignment does have variations in the offset, overhang and effective length (not much, but some) - but NOT in the pivot-bearing (mounting) distance. |
Dear Axel,
the SME 300 series is one of the very few tonearms which does come with a kind of "fixed" geometry in ALL parameters. Given its unability to adjust offset, overhang (we can just move the base - which we shouldn't... - NOT the cartridge ) and effective length, it surely is a fairly unique sample.
SME took for granted all industry standards of its day (early 1980ies) and said:
"well, if all cartridge designers do obey to and follow the standards given and if all LPs are cut following the new IEC standard, then evrything will be perfect with our new tonearm - it will be the "best tonearm in the world"............"
But the world is an imperfect one and many people do want to go their own ways.
The new SME surely was the LEAST UNIVERSAL tonearm ever designed .......
It is for sure the one tonearm which gives almost no possibilities to adjust to specific cartridge needs or to different arcs.
The SME V was a child of its day and was regarded when introduced as the first tonearm which took all (some fairly new...) industry standards for record-cutting and cartridge dimensions serious.
Too serious.
In a biological sense the SME V is the very opposite of evolutionary versatile.
It can not "adjust" to any change in the "enviromental conditions".
With the "right" cartridge, it is a VERY serious tonearm.
But there are so very few "right" cartridges for the SME V around....... |
Dear Raul,
yes, the analog world is an imperfect one and will always be.
I just think that in tose few areas where we do have pure sientific parameters - teh geometry - we should try to use them for the very best results and should follow them as strictly as possible.
There are so many other segments of the analog front-end, where our "feel" and "intuition" is of paramount importance - cartridge, cables, VTA, VTF etc.
Here however, pure geometry is I believe of great help.
This is the reason why I permanently insist on the strict application of the 2 geometrical calculations for the complex tonearm/cartridge topic.
Its the foundation of all which follows in the audio chain.
Making any mistake here, will make it VERY hard - if not impossible - to fix that "bug" ever after. |
Dear Axel, as for your quote:
"""""A lot of folks don't want to know the details of their car's differential gear, but simply use it.
So, that said, it might make a case for Linn and SME's non-variable approach.
I'm also not really sure if a very 'funky' adjust-all approach is the last answer to all this."""""
The reason why today we can just enter the car and drive without knowing the details and without having to adjust some things before starting the engine is, that in the past 100+ years a lot of well-educated engineers have put endless work into the complex topic "automotive car" and have solved all problems (and there were an endless number of problems in the early decades and still today cars are improving).
We are far from that state of development with analog front-end.
Far less time, far less high-trained manpower, far less money.
Till we can use analog front-end with the same ease as our cars, I will have a long white beard...... and I am not that old yet. |
Dear Raul, I will set up - for a friend of mine - a SAEC-506/30 in two weeks - mid May. I will have some news and geometrical details after I have done so. If anyone interested, I will gladly supply all findings. |
Dear Berlinta, the choice of an inner (2nd) zero close to the label makes sense too, if you own a large collection of early classical stereo LPs made by Mercury and/or Decca (to name the 2 major labels who hadsome of the most daring cutting engineers...) in late 1950ies and first half of the 60ies.
Ask hundreds of collectors of valueable vintage LPs.
Here we often have run-out grooves sometimes starting within less than 8 mm before the paper label. Especially with some of the most dynamic recordings. And then the large final tuttis are very close to the grooves end.
Its not all singles.......
There never was a "norm" from IEC and the AES for the stylus - mounting holes ?
Well - there was and is one.
The fact that so many manufacturers do not obey to it, doesn't mean there is none.......
Anyway - these are windmills....... I won't make the same mistake as Galileo did. I leave the discussion in this thread for good - this step will surely get some applause, as it leaves the field to others to shine........ and increase their sales. |
Dear all, after we have now learned that finally all parameters of the tonearm geometry are variable, nothing can stop us now entering analog heaven.
If any of you will still suffer inner groove distortion....... well, don't worry that happens. Move your tonearm, rotate the cartridge. If it distorts now at the run-in grooves? Hey - be flexible. Times may be hard, but modern. |
Dear Berlinta, it is very difficult to say something "straight", if your post is not approved by the moderator and therefor never actually posted (which happened with several of my posts in the dispute about the turntable drives when I was "against the gang" - thats why I moved out of that discussion).
Galileo was an analogy of course, as were the windmills - but I think my point is clear.
For many small audio business today the online forums are the best way to marketing their product(s).
To do so, they must maintain their status of authority in the segment of the audio market their product is located.
This is legitimate - of course.
When this status is endangered in any way, it becomes an ego battle very soon - quod erat demonstrantum in the discourse about the bearing friction which became a dispute about turntable motor drives in general. |
Dear Raul, you are right.
Maybe its just one dogmatic ego which can't stand his mirror image......
I just do not see the term democratic transferable to the world of physics, mechanics and geometry. |
Dear Berlinta, as I announced before: - I leave this thread now.
Our dispute doesn't bring this thread forward in any constructive way. |
Dear Siniy123, I absolutely agree with you.
With classical music however the mastering engineer has no choice, but to put the tracks where they belong. As most of the big climax in classical (especially of course symphonic music...) music are at the very end of the movements we usually see the end of a romantic symphony towards the inner grooves.
As we can do little to get the industry alter the polish/stylus quality, we should optimize the position of the stylus at the most critical part of the groove.
Thats why I vote for an alignment which puts the 2nd zero closer towards the inner grooves to bring the stylus in the best possible position when the going really gets rough.... |
Genesis168, the Denessen Soundtraktor has only one grid/one point for alignment. |
