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 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.
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.




@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  : 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.