Assuming you’re not using stepup transformers, the optimum
impedance for a LO (.24mv) ZYX will usually fall somewhere between 50
and 200 ohms. The ideal value will vary from system to system, since it
depends on the electrical characteristics of the tonearm cable, phono
cable and other components
This statement is false, for the reasons I outlined earlier.
If you are using step-up transformers, I’ll need to know your step-up
(turns) ratio or gain (in db) to make a recommendation. MC’s are
extremely sensitive to impedance loading when the signal is going into a
step-up, so more experimentation will be required."
This statement is misleading. MC cartridges are not sensitive to transformers, its the other way around- transformers are sensitive to MC cartridges. How it works is a transformer **transforms** impedance. So if your cartridge is 10 ohms, the output impedance of the transformer will be twice what it is if the cartridge is 5 ohms.
The loading required by the transformer will be different for each cartridge used. This is to prevent the transformer from ringing (which causes harmonic distortion so it is important if you want to hear what's really going on).
If the transformer is not loaded at all, or too lightly, it may not even express its turns ratio at its output- instead it can express its inter-winding capacitance, acting like a poor coupling cap with bad frequency response!!
So loading an SUT correctly is really important!
