FR-7fc is indeed very rare, but only this model in entire FR-7 range has 0.65 mil CONICAL TIP at the same time higher retail price in 1981 according to this page. But the output at their comparison chart is incorrect for some models, so i will add correct info:
*The best cartridge in FR-7 series is FR-7fz (not 7fc)
The "fz" has a Line Contact stylus tip and 0.24mv output, 5 Ohm impedance.
The "fc" has Conical tip and 0.2mV output, 2-3 Ohm impedance
The "f" has 0.15mm square shank Contact Line stylus and 0.15mV output, 2-3 Ohm impedance.
My advice is to upgrade to FZ
When i did that from F to FZ it was noticeable.
I believe you did not rank it as NUMBER ONE only because your FC has a conical tip, i'm sure when you will try FZ with Line Contact stylus it will be nearly impossible to find a better cartridge at any price if you have Fidelity-Research 64s or 64fx tonearm for this monster.
*The best cartridge in FR-7 series is FR-7fz (not 7fc)
The "fz" has a Line Contact stylus tip and 0.24mv output, 5 Ohm impedance.
The "fc" has Conical tip and 0.2mV output, 2-3 Ohm impedance
The "f" has 0.15mm square shank Contact Line stylus and 0.15mV output, 2-3 Ohm impedance.
My advice is to upgrade to FZ
When i did that from F to FZ it was noticeable.
For what its worth I’d rank the FR7fc as the second best, coming closest to the musicality of the LDR.
I believe you did not rank it as NUMBER ONE only because your FC has a conical tip, i'm sure when you will try FZ with Line Contact stylus it will be nearly impossible to find a better cartridge at any price if you have Fidelity-Research 64s or 64fx tonearm for this monster.