SUT - electrical theory and practical experience

not sure you clearly understand the need to use a SUT.

Moving Coil cartridges are different technology than Moving Magnet. MC, the small lightweight coil moves (rather than the heavy magnet moving). Allowing a refined and more accurate signal fidelity (or so most believe to be true).

Lightweight moving coil makes a weaker signal strength. That low signal needs to be MAGNIFIED (not enhanced), just boosted in strength enough to be essentially as strong as a MM cartridge’s strength.

At MM strength, the/any phono signal needs to be ’equalized’ by the industry standard RIAA curve. That is what a ’PHONO STAGE’ does. Phono stage can be a dedicated phono input in a preamp or built into a separate Phono Stage.

Once ’equalized’, it is equal to any LINE level input, i.e. AUX, line 1,2,3 ...

....................................

SUTs, MC cartridge (step up transformers), need no power, their internal transformers have alternate windings that modify/boost (but not enhance) the signal strength simply by the specific design of the transformer.

........................................

Voltage Transformers are very different. i.e. My Japanese Turntable is designed to run on Japanese standard voltage of 100 volts. I need a STEP DOWN transformer, that converts my USA 110/120 volt down to 100 volts, and I plug my 100 volt TT into it. Those are powered devices.

Step Down transformers exist also. They alter Voltage.

lewm

I wanted OP to understand:

cartridge SUTs are PASSIVE, no need to plug them in. And that they boost signal strength by themselves, i.e. boost, not ’enhance’ the signal.

Step Up or Step Down NEED to be plugged in to wall outlets. They also boost/cut voltages and do not enhance signals.

And a Cartridge SUT is working on a phono cartridge signal that goes into the preamp/amp/speaker system

A Step Up/ Down Voltage converter has nothing to do with the audio signal, just proper voltage to the motor.