Fidelity Research cartridges

Does any one know if the MC702 have Alnico magnets?

The FR series look very similar to the Sony XL-55 series with the figure 8 coils. Who manufactured the FR and the Sony carts?

I don't have an FR series (yet) but I have three of the Sony XL-55/88 pro series and they give my UNIverse and Allnico Z a run for their money.

Steve

Hi Marco (Heradot): I didn't see your post for the longest time, apologies for the tardy response!

First, I removed anything on the arm structure that wasn't absolutely essential for playback. That means in particular the armlift, also the armrest. IIRC, I remade the armrest as a separate piece which was secured to the armboard/plinth. I normally have no need for an armlift, so I simply removed that.

I would have liked to have removed the horizontal plate that holds the armlift, but IIRC you would need to dissassemble the arm to achieve this, so I grudgingly left the horizontal plate in place. But I did use blocks of paulownia wood between the horizontal plate and the armboard (or turntable plinth). Paulownia is somewhat like a high-strength version of balsa - it is light and strong, internally lossy, and is also somewhat compressible (albeit less so than balsa). This will help control the ringing of the horizontal plate and will clean up the sound.

And as Raoul suggested, I use the Warren Gehl armwrap, which is far more effective than heatshrink. It dampens the resonances of the armtube by compressing it radially, and works on a similar principle to how you play harmonics on a bass or guitar.

The armwrap's radial compression of the armtube makes the 64S and 66S operate a bit more like Ikeda's later arm designs like the IT-245 and IT-407, although these added interference damping by force-fitting multiple concentric tubes of various materials together.

FWIW, from the resonance-control point of view, Ikeda's personal favorite among his own designs is the IT-345, which I believe has a three-way concentric armtube structure. The person who's been building these arms for the past 20-odd years is of the same opinion.

As an aside, I normally used a combination of dynamic and static VTF, and balanced the contributions of the two to achieve a sound that was subjectively most pleasing. Note, however, that the turntable that I preferred to use with the FR-64S was a Micro-Seiki SZ-1S, which has a vacuum clamp and therefore little LP warpage and little vertical arm movement to speak of.

Finally, the headshell has a major impact on the sound, but I am sure that you are well aware of that.

best and hth, jonathan carr

Steve, Jonathan may be able to shed some light on this but as far as I know, there was no business relationship between Ikeda-san of FR and Sony Soundtec. The magnet structure is different, and I thought the XL-55 and 88 have different coil concepts than the FR-7. The XL-55 is heavy, the FR-7 is even heavier; but lucky thing is, the FR-7 and the XL-55 have the same distance from headshell mount to stylus tip, meaning the FR-7 fits perfectly on tables/arms which take the XL-55 perfectly.

FWIW, I'd be happy to send you an FR-7 in exchange for your XL-88 if you ever wanted to...

Dear Perrew: Maybe not because according with this:
http://74.125.95.104/search?q=cache:1fIRyl0l5NgJ:www.audioinvest.no/fr/products/frc_702.htm+fidelity+research+mc-702&hl=es&ct=clnk&cd=3&gl=mx

has only two magnets and usually when a designer put Alnicco use more than two.

Maybe Jcarr could have a more precise answer. Btw, why is so important to you?

Regards and enjoy the music,
Raul.