Ikeda IT-407 tonearm geometry


I’ve read all there is to read on this subject and never got satisfaction. It inspired me to ask this question earlier.
“Cartridge alignment with non slotted headshells”. 
The main reason I have a problem with these headshells is with my Ikeda it407 (chrome) tonearm, the cartridge must be twisted quite a bit in towards centre.  I have a vintage audio technica headshell with fixed holes and I don't even need a protractor to see that it won’t work. I don’t think stevenson alignment is this bad? I don't have a protractor with stevenson. My pivot to spindle distance is set perfect using my smartractor. I’m quite sure it is not possible to use an spu headshell in my Ikeda with the tonearm at the recommended distance without being seriously out of alignment. I’ve researched this online and I’ve spoken to Bill Demars at Beauty of Sound.  He said that the recommended pivot to spindle distance is probably wrong and some people position at a further distance. He agreed about spu in spu headshell in the ikeda arm not being ideal. I’ve never heard if anyone has asked Ikeda these questions about their arm. 


I do really like this arm, the way it sounds and the fact that is has a removable headshell, 
I’d just like to have better understanding of it? 



sdrsdrsdr
Dear @sdrsdrsdr  : The Ikeda/FR specs are out of any alignment because they say overhang 12 mm, so they manipulate numbers.

My take is to make the alignment according the P2S distance I posted and 13.28mm on overhang with an offset angle: 17.72°

R.
@rauliruegas 


I’ll have a look closer at what you said later tonight. At the moment I still don’t quite understand. I appreciate all the input though. I’m really enjoying learning more about vinyl playback. I’ve always been into vinyl except for a while in the 90’s. Before the last couple of years, I only had a single table set up, usually without changes for years at a time. The last couple years I’ve gotten into multiple tables, arms and cartridges and having more fun than ever.
dEAR @sdrsdrsdr : """ Then Raul gave his recommendations for it407 and his p2s was shorter than recommended. I was just hoping for a more general consensus. """

YOU HAVE A TOTAL MISUNDERSTOOD ON ALMOST ALL WHAT i POSTED HERE.

It’s normal your misunderstood when M.Fremer ( in those times. ) had a bigger misunderstood on the overall subject and this is what I’m talking about and why I posted what I posted in your thread: for we can understand it and seems to me you did not yet.

This is what I posted on the 407 and I took the manufacturer effective length specification ( one of input alignment calculations. ), I did not change it. The P2S is only one of the calculation outputs achieved by difference in those calculations using Löfgren A and is not  my recomendation but a result of the calculations:


""""""" P2S: 293.718 . I used and use Löfgren A. Many years ago I used Löfgren B. Before I learned my tonearm set up always was made according manufacturer specs, not any more.

https://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=el&a1lv=307&a1=la&oh1v=&oa1v=&arm2=Lofgren+A&l2=el&a2lv=307&a2=la&oh2v=&oa2v=&arm3=Lofgren+B&l3=el&a3lv=307&a3=lb&oh3v=&oa3v=&arm4=Stevenson&l4=el&a4lv=307&a4=st&oh4v=&oa4v=&og=iec1&ogv=&ig=iec&igv=&cal=y&submit=calculate """"""""




Got it? That alignment can be use exactly for the FR66 too following the manufacturer EL spec.

Any thing different down there is only input/output number manipulations with out foundation but any one can do what any one wants it. Anyway, Ikeda-san is an ignorant on the overall alignment subject and its advantages/disadvantages. Period.

R.




Dear friends: I posted that any one of us can manipulate in any tonearm any of the input alignment calculations and this means that each one of us can have a self " designed "/dedicated propietary alignment.

That’s what the SAT tonearm did it when he refused to use the input parameters of the standard inner/outer groove radious and that’s why the SAT tonearm must be aligned by the seller/distributor. Has any advantage what he did it? not really because we can use Löfgren A/B there and evertthing will be fine.

It does not exist any NEW alignment as that DIN that an Agoner posted. What the gentleman down there did it was a manipulation of the input most inner groove radious. He took 54.00mmm for that distance and use Löfgren B alignment and that’s why in the analog planet link appears those null points values.

Here an easy calculation about where any one can corroborates what I’m saying:

https://www.vinylengine.com/tonearm_alignment_calculator_pro.php?arm1=Arm+1&l1=el&a1lv=307&a1=la&oh1v=&oa1v=&arm2=Lofgren+A&l2=el&a2lv=307&a2=la&oh2v=&oa2v=&arm3=Lofgren+B&l3=el&a3lv=307&a3=lb&oh3v=&oa3v=&arm4=Stevenson&l4=el&a4lv=307&a4=st&oh4v=&oa4v=&og=iec1&ogv=&ig=cus&igv=54.0&cal=y&submit=calculate

any advantage?, no only higher error. Btw, I have not a LP that been recorded at 54.00mm inner groove radious. So that data manipulation is futile and useless for say the least. Vive le IgnoraCE ! ! ! ?

Obviously that due our normal low knowledge levels on this alignment specific subject those kind of data manipulations looks as something new/invention. Those gentlemans are taking advantage of our ignorance levels about and nothing more.

R.
Steve, with your name you must get Stevenson
sorry, it was hard to resist :) 

Seriously, always try first what manufaturer recommends, Ikeda-San is the legend in High-End world. 

You can ask @halcro for his FR-66s PS distance, it must be the same as Ikeda 407. 
@chakster 

Yes. It got a little off track. I’ll have to get a protractor for Stevenson and give it a try. You said your short  ikeda lined up properly without having to twist The cartridge in the headshell. Using Lofgren I have to twist my cartridge quite a lot in my long ikeda.  So much so, that I’d be surprised that Stevenson would be much different. But I haven’t tried yet so I can’t say for sure.


As I said in my opening question, I did speak with the USA distributor and never got clear answers either. He did say that many people preferred a longer p2s. And he uses a longer measurement than recommended too. Then Raul gave his recommendations for it407 and his p2s was shorter than recommended. I was just hoping for a more general consensus. I will get a Stevenson protractor and hopefully have a better understanding.

Steve.
Over and over again, every year, oh my god.
No one can HEAR it, Japanese tonearm designers continue to use Stevenson. The one who claimed to hear it (M.Fremer) is using SAT tonearm that received tons of criticism on here because of is geometry.
People contradict to each over, some people contradict to themselves.

Normal people continue to enjoy music with whatever alignment (Baerwald, Lofgren or Stevenson ... or maybe something new like Uni-Din).

I will add more frustration:  Rigid Float/Ha , a very short 7” inch tonearm !
HOW ABOUT UNDERHANG  5~20mm ?

Dear @bukanona : That’s why Stevenson is no truwe alternative alignment and you can see it in the analog planet link that posted @sdrsdrsdr .
Yes, the tracking error is independent of what your link stated but has a relationship that we can't just forget. Btw, the article gentleman said that to align the cartridge body through protractors but in reality we all know that what be stay perfectly aligned with the protractor lines is the cartidge cantilever.
R.
I was struggling to remember where I have saw the text which have changed my mind about alignment
It’s Stereophille
https://www.stereophile.com/reference/arc_angles_optimizing_tonearm_geometry/index.html
and if to "cut" the core is in the very end so will just copy it:

In all that has gone before, we have assumed that the Löfgren-Baerwald approach of minimizing the maximum LTE 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.

Although tracking-error and tracing-error distortions are different, there is clearly a case for supposing that, as tracing error increases toward the end of the side, tracking error should decrease. In this case, the optimal arm/cartridge alignment might be one that results in a distortion-vs-groove-radius curve like that in fig.10. But as tracing error differs according to stylus type, this approach also suggests that arm/cartridge alignment should vary accordingly, with a bigger disparity from the conventional alignment for a conical stylus than a line-contact stylus. The concept of a single "right" alignment would then be redundant.


Dear @lewm : Your post has no sense for me and useless to this thread.

Btw, 1938 was the year E.Löfgren alignment studies and in 1941 Baerwald appeared with the same Löfgren A solution, nothing new with.

Who cares what was available back then. 
Certainly not me or Löfgren because it not matters to calculate tonearm today or back then overhang and offset angle ! ! !. The Löfgren solutions are valid then and for ever no matters what.

Your post ? ? ? ? 

R.
Before anyone will tell how Michael Fremer can hear distortion please read this post about his favorite tonearm called SAT. You will be surprised to read about SAT tonearm geometry, this is Michael's favorite. 
Dear @sdrsdrsdr  : I posted in that Analog Planet thread because not even M.Fremer understand it the whole subject at 100%. I explain my take on the alignment issue and there I explained how was manipulated the parameters for that comparison alignments subject in the thread.

R.
In favor of not taking this business too seriously, for me, is the fact that the papers on alignment were mostly formulated and published in the late 1930s.  I think the Baerwald/Lofgren dates to 1941.  Not that the rules of geometry have changed since then, or ever, but think of what was available back then in terms of equipment.  And forget LPs or stereo reproduction.
@rauliruegas 

What pivot to spindle distance do you use for your it407? And it the cartridge rotated substantially inwards or straight in the headshell?
@chakster 

if this graph is correct, wouldn’t it give you the most distortion when your playing your small  45’s except for the very end of the song? 

https://www.analogplanet.com/content/uni-din-versus-löfgren-b-just-clarify
It's THD tonearm war and it have roots from nineties followed by small moving mass marketing campaign. 

Technics engineers in Japan who designed SL1200G tonearm with alignment method that is very close to Stevenson (almost identical) must be very s****d then.


In my own defense I should probably add that my Reed 3P tonearm with fixed headshell uses the Baerwald geometry. As much as I’ve tried, I’ve never been able to conclude that this set up sounds superior in any way to the others.

@edgewear same here with my Reed 3p "12 with Baerwald and vintage FR and IKEDA with Stevenson
Dear @sdrsdrsdr @edgewear : Löfgren was and is the gentleman who made the overall research that permits him to develops the formulas to make the critical tonearm/cartridge set up calculations parameters.

What wanted Löfgren to calculate?, two main data/parameters: overhang and offset angle.

He took 3 precise and know input data for the overall calculations: tonearm effective length, inner most and outer most groove distance/radious ( LP. ).

Löfgren main output data/parameters are: overhang, offset angle, both null points and by difference P2S distance.

But Löfgren made two calculations alignments: A and B where the difference in between is only in the overhang distance.

After Löfgren alignments several other gentlemans tryed two make their own kind of alignments but at the end almost all of them finished with exactly the Löfgren A alignment calculation. This was and is the case of Baerwald that is similar to Löfgren A.

From where took Löfgren those input data/radious? from the IEC standard that defined that those LP inner/outer radious are: 60.325mm and 146.3mm.
Exist, at least, other two radious standards: DIN ( Germany. ) and JIS ( Japan. )

Stevenson made two alignments: one similar to Löfgren A calculation and the " stupid " Japanese Stevenson alignment where he took the inner most groove radious as the inside/second null point, he defined that way this null point: coincide with the most inner groove.
This Stevenson alignment is the worst one of any alignment and not opnly because has the higher tracking error/tracking distortion levels in the LP surface recorded grooves but the last/inner 3mms. grooves but because in reality the higher tracking distortion levels are over all the LP surface due that those inner 3mms. are only when a LPhas recorded grooves from around 58mms. inner groove to end of LP.
How many of our LP’s has recorded information at 58mm. inner groove?

In the other side, all input/output Löfgren calculations parameters can be " manipulated " no matters what specs were given by the tonearm manufacturer. We can change it. We can have our self dedicated alignment with different paramenters and different tracking error and tracking distortion levels too ( normally higher. ).

@edgewear, you are not thin ears, in reality exist those differences but not something as " nigth and day " and we need to know what to look for to detect those differences and that our room/system have high or very high resolution.

Why I posted the word stupid to that alignment and people that use it?

Because for me any person that for very low knowledge levels on some specific subject ignores the true behind that subject is ignorant about but if through several years that same person mantained that kind of ignorance then the person is no more ignorant but stupid because has not the capacity to learn on that subject and with all respect Ikeda-san is one of this kind of persons.

I had the opportunity to know the king of stupids in this precise alignment subject and unfortunatelly belongs to this forum and as a fact are two persons that figth in between to achieve that title. The question here: who will win the title?

Btw, I owned the 407 too.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
Perhaps I’m an idiot with tin ears, but in my experience the sonic differences between the various alignment geometries shouldn’t be exaggerated. I use FR 64s and 64fx tonearms with the specified P2S distance of 230mm, which means that the geometry is Stevenson by default. This way I can use my FR7 and SPU cartridges with correct alignment. On my Audiocraft AC-4400, using a variety of cartridges in a variety of headshells (slotted or otherwise) I have experimented with the other geometries, including Audiocraft’s own (which is neither Baerwald, nor Löfgren, nor Stevenson).

The sonic difference between these various geometries was so negligable in my system and to my ears, that I decided to use Stevenson for the Audiocraft as well. This way I can use my cartridges in all three arms, without having to make changes to their position in the headshell each time they go from one arm to the next. Yep, I’m a lazy idiot as well.

In my own defense I should probably add that my Reed 3P tonearm with fixed headshell uses the Baerwald geometry. As much as I’ve tried, I’ve never been able to conclude that this set up sounds superior in any way to the others. If anything, I’d say Stevenson is preferable with classical music, as these composer guys like to go out with a bang. You may have noticed this usually happens at the end of the record side, where inner groove distortion is likely to be most severe.



@bukanova

 In most of the records crescendo occurs in the very end (at least in classical and jazz) so with cartridges like SPU which are not the best trackers I do feel more safe to have Stevenson as it less possible that it will damage inner grooves of record.

Exactly, i can only remind others that we have not only big "12 inch records, but smaller "10 inch EPs and "7inch singles. On smaller format of vinyl there is nothing located that far from the center hole, because the radious of the record is much smaller. I've posted about it before, on "7 inch records everything located in the field where on "12 inch located only last two songs maximum. Stevenson alignment is not for idiots. 

But anyway, most of us using at least two tonearms and we can compare one to another with different alignment methods. I have 4 tonearms in use, some with Baerwald, some with Stevenson, some with manufacturer's own alignment.  

Dear @sdrsdrsdr  : There is no problem with Ikeda geometry. The problem is to understand how the tonearm/cartridge set up alignment works.

Forgeret about the Ikeda specs because you can change the effective length of any tonearm changing the pivot to spindle distance ( not making the change through overhang. ) and use an alignment calculator to set up your cartridge to the new parameters.

You have to " play " with that effective length change till you find out the one for that cartridge.

https://www.vinylengine.com/tonearm_alignment_calculator_pro.php

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.


Uni-Din is interesting. But although I am not sure that it's worth the effort.

In most of the records crescendo occurs in the very end (at least in classical and jazz) so with cartridges like SPU which are not the best trackers I do feel more safe to have Stevenson as it less possible that it will damage inner grooves of record.

My proposal is if you do any changes by yourself buy test record and use tracking tests as after trying different alignments you have to be sure that you haven't made some hard errors then aligning cartridge.
I thought I would try Stevenson but I keep hearing how poor it is. Maybe uni-din is a better choice. Check this out.

Bad things about Stevenson alignment coming only from one user on this forum, many others are happy with Stevenon and can’t detect any problem using headshell integrated cartridges like SPU or FR-7 series with Fidelity-Research or Ikeda tonearms.

You have to check and decide for yourself.
I’m using Baerwald on some of my tonearms with many cartridges when re-alignment is not a big deal using proper headshells.

Anyway, maybe i’m just not so old to hear distortion, i can’t say anything bad about Stevenson alignment method and if you will read more about it there was the reason to invent this geometry, especially for those who’re into classical music.

With FR64S or fx, optimal P2S if you want to use Baerwald is 231.5 and indeed in that case cartridge will be twisted inward with respect to long axis of headshell. So probably the same applies to Ikeda which was also designed for Stevenson.
I recommended Dr.Feickert because you said this:

I don’t have a protractor with stevenson.

Believe it of not, but i don’t like mirror under cartridges, i have very bad experience with Van Den Hul mirror protractor, i prefer white lines on black surface (just like Feickert, better for my eyes) and it’s enough for me to align cantilever with these lines. Additional light is a good bonus for Feickert. A good vision is also good bonus, i can handle it.

You can always order Stevenson protractor for one particular tonearm.

If you don’t need Stevenson alignment at all it’s another story, but then you will have to twist your cartridges in the headshells on Ikeda.



@chakster 

Before you recommend something you should check out the two protractors that I use. The Dr Feichert is known to be very good. The two that I mentioned are just better as I stated they have the mirrored hologram. I find this is the only way you can look at zenith and know that your looking at it at the right angle. Much more accurate. 
The main reason I have a problem with these headshells is with my Ikeda it407 (chrome) tonearm, the cartridge must be twisted quite a bit in towards centre.


I have Ikeda IT-345 with original headshell. The reason Ikeda-San made the shape of the headshell so strange is because he did it for his own IKEDA cartridges first. BUT overhang is adjustable on the shell, so you can move it forward or backward. Azimuth is adjustable too. This shell is definitely not cool for square shape cartridges, looks a bit ugly together. It's perfect for IKEDA cartridges and for something with rounded shape as Miyabi Standard, Miyajima etc. Why don't you just buy IKEDA cantilever-less cartridge for this wonderful tonearm? 

 I have a vintage audio technica headshell with fixed holes and I don't even need a protractor to see that it won’t work. I don’t think stevenson alignment is this bad? I don't have a protractor with stevenson.

Which one ?  When AT made Technihard series they made two versions (short 13 and long 15) with adjustable overhand and azimuth. 


My pivot to spindle distance is set perfect using my smartractor. I’m quite sure it is not possible to use an spu headshell in my Ikeda with the tonearm at the recommended distance without being seriously out of alignment. I’ve researched this online and I’ve spoken to Bill Demars at Beauty of Sound.  He said that the recommended pivot to spindle distance is probably wrong and some people position at a further distance.

Can't comment on long version, but since the IKEDA IT-345 and FR-64s share the same PS distance (230mm) i think IKEDA IT407 and FR-66s protractors are the same too (just longer PS) ? 

IKEDA-345 and FR-64s / FR-64fx alignment method is Stevenson. 

I don’t think stevenson alignment is this bad? I don't have a protractor with stevenson.

I recommend you to buy Dr.Feickert protractor to have 3 methods in one protractor (Baerwald, Lofgren and Stevenson). It's great tool for any turntable and any tonearm, worth the investment (top quality product, made in Germany).