Most audiophiles never have the opportunity to hear the legendary Fidelity Research LOMC cartridges comprising the FR-7 Series.
Here's what Jonathan Carr says:-
FR-7f
Fidelity-Research FR-7f specs:
â Price in 1980 was 77,000 yen
â Power generation method: MC type cartridge
â Output voltage: 0.15 mV (3.54 cm / sec., 45 °)
â Output voltage: 0.2 mV (5 cm / sec., 45 °)
â Output power: 2 Ă 10 -8 W (5 cm / sec 45 °)
â Needle pressure: 2 g to 3 g
â Load impedance: 3 Ω
â Coil impedance: 2 Ω
â Playback frequency: 10 Hz to 45 kHz
â Channel separation: 28 dB (1 kHz)
â Channel balance: 1 dB (1 kHz)
â Compliance: 7 Ă 10 -6 cm / dyne (100 Hz, 20 ° C.), the compliance measured at conventional 10Hz will be about 13cu!
â Tip: 0.15 mm square Refined contact, Solid Diamond needle (LINE CONTACT)
â Weight: 30 g
Even fewer audiophile ever have the opportunity to compare the BEST of the FR-7 Series.....the FR-7f and FR-7fz
FR-7fzÂ
FIDELITY RESEARCH FR-7f LOMC CartridgeÂ
FIDELTY RESEARCH FR-7fz LOMC Cartridge
Here's what Jonathan Carr says:-
Here you can see just how huge the magnet structure is, and if you understand cartridge design, the uniqueness of the 7's innards will be very apparent. The magnet structure alone would spill over the body sides of any non-integrated headshell MC cartridge (at least that I am aware of), and underscores why FR never made a non-integrated headshell version of the 7. From my perspective (that of an active cartridge designer), the closest thing to a non-integrated headshell version of the FR-7 was the PMC-3, but even this remained quite a way off. The FR-7 had a radically different coil former (cube-shaped), likewise for the magnetics (dual magnets, quad polepieces). IMO, the FR7s were by far the most interesting of FR's MC designs, but the 7's basic design concept dictated that they would always be big, heavy monsters, suited for relatively few modern arms... My favorite FR-7s are the f and fz. The very low coil inductance of the FR-7 implies that loading can be fairly flexible, so I wouldn't be so concerned with the low impedance. Also, none of the FR-7s are overachievers in detail, and the top end extension is a little curtailed. so the downsides of transformer stepups won't be overly apparent. However, in consideration of the low coil inductance, should you choose a stepup transformer, I would look for a toroidal-core type.Â
FR-7f
Fidelity-Research FR-7f specs:
â Price in 1980 was 77,000 yen
â Power generation method: MC type cartridge
â Output voltage: 0.15 mV (3.54 cm / sec., 45 °)
â Output voltage: 0.2 mV (5 cm / sec., 45 °)
â Output power: 2 Ă 10 -8 W (5 cm / sec 45 °)
â Needle pressure: 2 g to 3 g
â Load impedance: 3 Ω
â Coil impedance: 2 Ω
â Playback frequency: 10 Hz to 45 kHz
â Channel separation: 28 dB (1 kHz)
â Channel balance: 1 dB (1 kHz)
â Compliance: 7 Ă 10 -6 cm / dyne (100 Hz, 20 ° C.), the compliance measured at conventional 10Hz will be about 13cu!
â Tip: 0.15 mm square Refined contact, Solid Diamond needle (LINE CONTACT)
â Weight: 30 g
Even fewer audiophile ever have the opportunity to compare the BEST of the FR-7 Series.....the FR-7f and FR-7fz
FR-7fzÂ
Fidelity Research FR-7fz Specifications
Frequency Response: 10 Hz to 35 kHzÂ
Channel Balance: 1 dB at 1 kHzÂ
Dynamic Compliance: 13 m/mN at 10 HzÂ
Output Voltage: 0.24 mV at 1 kHz, 5 cm/sÂ
Internal Impedance: 5 ΩÂ
Tracking Force: 2.0-3.0 g, 2.5 g recommendedÂ
Stylus Tip: Modified with Ultimate Q4 DiamondÂ
Weight: 29 g (including integral headshell)
FIDELITY RESEARCH FR-7f LOMC CartridgeÂ
FIDELTY RESEARCH FR-7fz LOMC Cartridge