Input Impedance for ZYX
Some general comments, pertaining to more than ZYX phono cartridges obviously. 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. Experimentation in-system is the only way to determine the optimum impedance for any MC. I’d suggest starting at around 100 ohms, then moving up or down from there depending on sonic results.
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.