12-24-09: Lewm
Do you guys think that the 47-ohm load would also be optimal for the MC7500, given the familial relationship among the MC7500, Windfield, and MCA90 cartridges? I like the MC7500 at 100 ohms very much. If I would critique it I would say that it is slightly "dry" sounding, gives lots of inner detail but maybe not so much in the way of "goosebumps". On the other hand, I came to it from years of listening to my Koetsu Urushi, so you could say I had been conditioned to a different sound that is anything but "dry".
Anything is possible but, going by the specifications, the MC7500 doesn't appear that similar to the Windfield/A90.
The MC7500 has very low output of 0.13mv and a 6ohm DCR (compared to 0.3mV and 4ohms). Clearly it has different electrical properties.
However since phono input loading *may* have more to do with damping the ultrasonic resonance peak (per Jcarr) - and how the phono amp deals (or doesn't) with this peak - it may be worth a try.
FWIW, there seems to be no consensus on loading for the Windfeld. A search here on Audiogon shows some people swear by 500-1Kohms - others say load below 100ohms. Unfortunately there appears to be no specific 'right' value that can be applied across all systems - but I think we already covered that above.