So if you used a 1:10 SUT, that would work because you would still be OK as far as the ratio of output R to input R. (If the MM phono stage provides a 47K ohm resistance at its input, a 1:10 SUT would result in the cartridge seeing a 470 ohm load, where the load is equal to the MM load resistance (47K) divided by the turns ratio squared, which is in this case, 100. 47,000/100 = 470 ohms, which is a bit more than 10X the 41 ohm internal resistance of the cartridge. However, the phono stage would then have to handle the nominal 9mV output of the cartridge plus SUT. Actually, most MM stages can do that, but beware of overloading the phono stage, because 9mV is correct for a specific stylus velocity. On complex music or during crescendos, the output of the cartridge might far exceed 9mV, and the stage might overload on peaks.