I have a Statement Reference 0.5 mV driving an Accuphase phono stage. The MC input (60db or 65db) gain setting opions can only load at 100 ohms or 500 ohms.
Only the MM input loads at 47K, but obviously does not have adequate voltage gain. I consulted Grado by phone: they advised that this variable reluctance design is not load sensitive and works fine driving low impedance phono stages. This "load insensitive" characteristic might be due to the shorter winding length of the low output design, although apparently the high output model behaves similarly so that's probably an incorrect assumption on my part.
Listening tests switching between 100 or 500 ohms: I preferred the 100 setting, although the differences were nearly indiscernable. If I recall (it's been awhile) the HF seemed a little smoother at 100. So no it does not seem to be an issue at all, rather academic at best.
I was thinking someday I might try replacing the low impedance input terminations onboard with 47K's just to try it, but I'm quite satisfied as-is so that might never happen anyway.
