Correct alignment for Fidelity Research 64fx/SPU?


Hello,

I've recently paired SPU Spirit with FR64fx (& additional counterweight).

FR64fx is mounted at 230mm pivot to spindle distance on my Garrard 301.

I currently experience a light distortion and mistracking. As I tried the SPU before on almost ad hoc mounted 3012 and that sounded technically correct (though not as convincing as with FR64fx in terms of emotional performance), I'm pretty convinced I will need to realign the tonearm.

I would appreciate any info related to an experience of 64/SPU users here, which would differ from a usual 230m PTS alignment. Also, I keep on reading that Stevenson alignment would be preferred, is there any explanation why so?

Basically I need to make a good decision as I have no armboard - whatever decision I make I will need to get a new top board with a new hole for a new alignment.

Many thanks!
anubisgrau
The set up instructions for the FR 64S and Ikeda 345 state a 50cm distance from the stylus to the headshell mount. Ortofon SPU's have this 50cm distance so there shouldn't be an issue if the arm is set up properly from the beginning.
"50 cm" = ~19.6 inches!!!!
Probably you meant to write "50mm", but I wouldn't know for sure.

I thought I read in one of Art Dudley's commentaries that the SPU required special mounting and/or tonearm adaptation. Dkarmeli's post suggests I was correct; the cartridge directly mates to the headshell mount on the arm wand. So I imagine you cannot either twist the cartridge in its mount to achieve, say, Baerwald geometry, nor move it fore and aft so as to achieve correct pivot to stylus distance. You have to take into account its stylus to mount distance when siting your tonearm pivot.
Lewm, That's correct, it fits directly into the bayonet mount of the arm. The only twisting you can do is for azimuth adjustment.
LOL....yes mm and not cm. I set all of my cartridges to 50mm stylus to mount distance and the SPU is just plug and play.
50 cm is equal to 19.6 inches. 2.54 cm per inch. Whew! I'm glad I got that off my chest.