SUTZ is a transimpedance step up. To replace any step up transformer application, internal or external, using the moving magnet phono stage or input. I find this to be absolutely wonderful in my system. People that like to use step up transformers in their systems may have a good understanding of this. This is in my experience, a much better solution for step up than any transformer I have tried, so long as your cartridge is one of very low internal impedance. Say below 20 ohm.
Why do people like stepping up moving magnet stages to use low output MC cartridges? Eliminating gain stages is the game here, and MM phono pres are much simpler typically, electrically, than MC phono stages. So SUTZ is a more transparent way to increase gain. Most MC preamps use some form of step up, via circuitry or a transformer. If you have the ability to use a SUTZ, I highly recommend giving it a listen. There is not a product page up yet, but it is coming. Feel free to ask me anything regarding, and I will try my best to help understand just what this special piece is and offers.