Recently discovered this vintage
Fidelity-Research catalog from the 80’s. This is the best illustration of LOMC cartridges designed by Isamu Ikeda for Fidelity-Research.
page with tonearms: FR-64fx, FR-64s, FR-66fx
page with SUTs, headshells like RS-141, N-60 nut, W-250 counterweight and accessories ...
page with Cartridges: FR-7fz, FR-7f, FR-7, PMC-3, FR-2, FR-1 mk3, FR-1 mk2, PMC-1
page with top of the line cartridges in order from the best models to lower models: FR-7fz, FR-7f, FR-7, PMC-3, FR-2, FR-1 mk3, FR-1 mk2, PMC-1 .... including MM models too.
Looking at the specs for each cartridge in the catalog you see that PMC-3 is the closest to FR-7 series. But the PMC-3 has higher impedance, lower tracking force, lighter mass, higher compliance. There is a tiny difference in frequency response only at high register, but i can assure you that the bass is tight and the highs are crystal clear.
Fidelity-Research PMC-3 has one serious advantage compared to the FR-7 series: the PMC-3 can be mounted on modern mid mass tonearms (on conventionel headshell). Fidelity-Research PMC-3 has its unique Air-Core Coil and Refined
"Vital" Contact Line stylus. So the PMC-3 is more user friendly on wider range of tonearms than FR-7 series.