Setup of Ortofon SPU Royal GM II in Ikeda 407

I would love some feedback on how people set up their SPUs in an Ikeda 407. The Ikeda has a few different setup parameters. The main one is to use 307mm from pivot to spindle and then just position the cartridge at the 50MM point in the headshell (measured from stylus to end of headshell) to get it right. But this does not conform to any of the known null points and has me confused. The SPU is 51 MM in length and going beyond in length is much worse than going less in length. Anyone w. experience to chime in would be appreciated. Remember the SPU Royal GM has the cartridge permanently fixed in the headshell. The only adjustment I can make is in the positon of the tonearm base.

From 2juki's web site for the 407.
" Overall length 388mm, Effective length 307mm Overhang 12mm"

Would that mean all you need to do is is measure pivot to spindle of 295mm, then add the 12mm for the stylus position??

This is how I set up my Ortofon 12 inch arm. Put the Ortofon ruler on the table and place the stylus on the 326mm (15mm after the pivot to spindle) effective length spot by moving the armboard. And you know that is easy with the Raven armboard.

If I am wrong, please someone let me know.

Dera Dgad: I think that Dowunder is right, try it and I'm sure everything will be fine.

Regards and enjoy the music.

The arm is such a warped creation. It starts straight, then bends away from the center axis and then back in. Overhand is specified at 12 mm. So Now trying to add 4 arms I had to move everything around. It aint easy. But basically to establish 12mm overhang I don't have a tool for that. I use a ruler to establish the spindle to pivot distance of 295 mm. But since the cartridgge is a bit longer (52mm vs. the 50 mm specification from the arm manufacturer) I am thinking to increase the spindle to pivot distance to 297 mm. I hope it works. The Ikeda does not follow any of the known setup parameters hence all the questions. It is supposed to have only 1 null point if at all. Mind you, there is a thread on Vinyl Engine but that leaves me as confused. I don't have the Ortofon tool. I normally use the 66 null point and arrow to pivot for most of my arms. I also realize overhang is an extrapolation from how the cartridge lines up if the arm is linear. Only that way can the overhang of 12 mm be accomodated. So measuring overhang at the cartridge needle seems also impossible. The arm has a few bends so I need to run an imaginary line etc. to get it right.

Raul, what do you do for your FR arms.
Dear Dgad: I have an old metal gauge from SAEC to measure the overhang right from the TT spindle.

Regards and enjoy the music.

Now that is what I need. That is ideal. Anything new like that?

The ortofon tool is only a plastic ruler with a drilled hole in the middle at the pivot to spindle point. You then just put the ruler over the spindle and measure the the correct mounting distance.

There is then a line at the 15mm mark which marks the effective length. You move the the armboard so that the SPU stylus sits on that line right next to the spindle.

That is it, as you know you can't change the alignment on the SPU due to its fixed headshell.

If you can drill a whole and mark the effective length on your ruler, that should do the trick.

let me know if you want me to email you a picture of the Ortofon ruler in action

Shane, I would love a photo. Would clear things up. I am more concerned w. overhang for the Ikeda than anything else. All other arms can use regular null points but the Ikeda geometry defys it. Let me explain to you my problem in more detail, If the arm effective length is 307mm (this is from stylus to pivot but not following a line through the arm as the arm isn't straight, instead it is based on probably the shortest distance between parralel lines that intersect both the stylus & pivot - it gets complicated), and the required spindle to pivot distance is 295 mm. But the stylus to tonearm collar (where the headshell meets the tonearm) is 50mm. If all is good all you need is 295mm pivot to spindle. With the SPU you have 52mm so I extended the Spindle to pivot distance to 297mm (adding 2 mm to compensate). This is due to Ikeda mentioning going past the 50mm is detrimental & better to be too short. Anyhow, so now, I did that & measured the overhang the best I could & I get close to 20mm right now. Truth be told there really is no way to measure overhang so really what am I doing. Anyhow, I am playing the SPU right now & it sounds magnificent. Better than before when I used the 66 null point. So go figure. But I want to be sure. I got my Colibri running in my Phantom & need to finish setting up the SQ again. Also, I need to finish setting up the Breuer which comes w. the worst manual I have ever received. One typed paper. Thanks to TW for a little coaching on this.