Fidelity Research cartridges

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.

Hi Steve, the XL55 and XL88 Pro cartridges are very interesting cartridges indeed. I had 2 samples of each during the past 6 years.
However - they do have little in common with the FR-7-series ( or FR-1 MK7..... I have found the original data-sheet with exactly this destination again - will make a photo tomorrow and post it) aside from both being an integrated headshell design and both featuring comparatively wide and hefty housings.

I do have the remains of a destroyed FR-7f at hand. According to one engineer at Munich Fraunhofer Institue the magnets are Alnico indeed.
And they are VERY big compared to most other cartridges.
The FR-702 does feature a significant shorter cantilever compared to the original FR-7-versions and thus the moving mass is considerably less resulting in improved low level detail and recreation of tiny details in the sonic picture.
You should NOT interchange a FR-7 with a FR-702 WITHOUT checking the adjustment of the geometry. It may very well be the case, that now the stylus sits somewhere else as before with the FR-7..........
VERY similar in sound and output (despite the claim that it had the very same output voltage in the data-sheets, I found on the 4-5 samples I had that the output was rather 0.15mV ) to the FR-7f.
Cheers,
D.
Cheers,
D.

Cheers,
D.