I recently acquired a low output (0.2mV) moving coil cartridge
(Sumiko Talisman B), for which the manufacturers' recommend a load of
40-100 ohms. I am currently running it into a load of 47k as my standard
RIAA preamp has sufficient gain, albeit with a bit more noise than for
the earlier MM cartridge, but nevertheless, perfectly acceptable. My
question is:- as MC cartridges are voltage sources (and Sumiko's manual
also says) then why should the load matter once it is, say, 10x greater
than the source impedance of the generator, which in my case is 5.8
ohms. The sound I'm getting seems fine, so I would like to know what
change/improvement I should expect from a lower impedance load.

Thanks

S.