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Fidelity Research cartridges

Any FR cartridge experts out there? Raul? Dertonarm? Syntax?
I have had an FR-7 which I bought a while ago. I tried it ever so briefly when I got it on an arm I now recognize as not being able to handle that weight (close, but no cigar). I just now pulled it out for kicks and after getting it adjusted with the big counterweight, I am VERY pleasantly surprised. Actually, I'm feeling kind of bubbly. It does not dig out the utmost in detail, but it just sounds very right.

Are there any other FR carts out there which are real steals if still in good condition? I know the MC-702 and the FR-1Mk2 and Mk3f by name, with good reps being assigned to the Mk3 and the MC-702. Given that the MC-702 and the FR-7 look quite similar, and they were offered at about the same time, what is different? And is the FR-7 just an integrated headshell version of the FR-1Mk3?
t_bone
chakster's avatar
chakster
6,144 posts
 
I want to make it clear for myself:
What a hell is "Refined Contact Needle" of the Fidelity-Research FR-7F (made in 1980) ? 

According to the manual for FR-7F:
"A unique refined contact needle which specially polished a solid 0.15 mm square solid diamond is adopted as a needle tip. The refined contact needle is a new system that combines the advantages of the line contact needle and the merit of the elliptical needle, making it less susceptible to adverse effects (noise etc.) due to warping of the disk and dust of the sound groove. Also, scratch noise and surface noise are extremely low, so you can obtain playback sound with high clarity and no fatigue."

So the stylus of the Fidelity-Research FR-7F is not conical, but some sort of Line Contact in stock condition ?

If it's not conical, i wonder why @halcro said it's conical and even re-tipped his sample with Axel (to have Line Contact) ?
 
nandric's avatar
nandric
4,086 posts
 

Chakster, That is how ''general opinion'' works. One does not

believe his own eye in order to follow the so called ''custom''.

I looked many times to my sample and assumed that a former

owner retipped the original ''conical'' with ''line contact'' stylus.

However in contradistinction to you I was more intriqued with

the question why Mitch Cotter has chosen FR-7f for his celebrated

TT and even made his own SUT for the precious? But my wondering

was based on two assumptions which may be not true. The first

was the conical stylus and the second that FR-7fz sounds much

better. Besides the ''fz''' has more ''modern'' stylus and has more

admirer than the ''f''. I  obviously followed the convention  by

which ''more admirers'' means that they are right in the sense of

majority rule (grin). I consider my FR-7fz as one of my best carts,

second to none, and still wonder how this can be possible with

a cart from the 80is? BTW Dertonarm advised me 10 years ago

to try one of those FR-7 kinds but I was very reluctant to  do so

because I thought that I would need separte SUT for each of

my MC carts (+40). When I got my Denon AU-S1 which covers

 2-40 Ohms I bought more Ikeda's carts instead of  SUT's.




r,

halcro's avatar
halcro
2,664 posts
 
If it's not conical, i wonder why @halcro said it's conical and even re-tipped his sample with Axel (to have Line Contact) ? 

Chakster, there's no question that the FR-7F had a conical (spherical) tip.
Vinyl Engine even gives its diameter as 0.65mm.
My one came with its original tip sheared off but its circular base was highly visible.
I sent it to Dietrich Brakemeier (Dertonarm) (who has worked on dozens of them) and he sent it to Japan to be re-tipped by the Master who apparently did the originals.
It came back to me with a decidedly conical stylus which frankly.....did not set the world on fire 😪
When this new tip also mysteriously sheared off....I sent it to Axel who recommended replacing it with a Line Contact which I agreed to.
My new FR-7F/Lc now sounded superb...and if you check the specs against the FR-7Fz, the only difference appears to be Output Impedance of 2 Ohms against 5 Ohms.

 
Ag insider logo xs@2x
rauliruegas
13,103 posts
 
Dear @chakster : The first F7 born in 1978 and came with line contact type 0.3x0.3mil.
The only conical FR cartridge in this series is the 1981 FR-7F/c.

In between the 7f and 7fz  ( 80-84. This the latest but not the more expensive that was the 7f-c. )

Refinement of line contact could means that is better polished but who knows what really means ? ?


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.
chakster's avatar
chakster
6,144 posts
 
@halcro Vinyl Engine info is not relevant, simply because the data for the first FR-7 and second FR-7F mixed up. In their wrong database FR-7 for some reason has Line Contact 0.3 x 3mil, but the next to it FR-7F has Spherical 0.65mil which is not true at least for the first FR-7 from 1978.
  
Axel just glued a new Line Contact stylus on original cantilever ? 

@nandric You said Axel is retired, do you mean retired from re-tipping business now ? 

@rauliruegas All i know is that FR-7F has square shank nude diamond of 0.15mm cross section, but i don't know the size of the tip. It would be nice to find out relevant info about it (original manual for example). 

Many times i saw them for sale and each time sellers claimed line contact for FR-7F. 


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