Reflected Input Impedance
The load impedance presented to the cartridge through the step-up transformer at a specified tap and secondary load.
A transformer changes the impedance seen across its windings. Ideally, a 1:n step-up reflects the secondary load divided by n squared to the primary.
Reflected Input Impedance — Step-Up Transformer (SUT)
For a Phono Step-Up Transformer, reflected impedance helps explain the electrical load seen by a moving-coil cartridge. It depends on both the selected turns ratio and the load at the following phono input.
For example, an ideal 1:10 transformer feeding 47 kΩ reflects 470 Ω. This illustrates the relationship; use the manufacturer’s stated figure and conditions for a particular product. Keep separate tap values paired with their corresponding ratio and secondary load.
Do not confuse reflected impedance with the cartridge’s own coil impedance or a recommended cartridge-impedance range. Changing the MM input load or adding loading resistors changes the cartridge’s load, so figures based on different secondary loads are not directly comparable.