There is another thread of much more recent origin around current-driven phono stages. But in any case, by definition, a current-driven phono stage with so-called automatic impedance loading would not require an SUT. As I think I wrote elsewhere, these stages try to offer zero input impedance to the cartridge, and they only work really well with very LOMC cartridges that have very low internal resistance, less than 10 ohms. (This is based on my own understanding of what I can find on the internet. I am not an EE; I only pretend to be one on Audiogon.) So, the first tube or transistor of the phono stage itself acts like an I/V converter to drive the downstream phono circuit with voltage output. It’s really not so complex. This circuit would work but less well with LOMCs that have internal resistances above 10 ohms, would not be recommended at all for HOMCs or MMs. But I guess the Phonata has separate dedicated MM inputs. I am curious to try one myself. Which is to say that I am curious to try a current-drive phono stage, not necessarily the Phonata. I've had my eye on the BMC MCCI.
Conversely to my description, if the Phonata does incorporate an SUT in its LOMC circuitry, it probably is not a current-driven phono stage in the technical sense, although I suppose you could say correctly that a SUT converts current to voltage too.
Conversely to my description, if the Phonata does incorporate an SUT in its LOMC circuitry, it probably is not a current-driven phono stage in the technical sense, although I suppose you could say correctly that a SUT converts current to voltage too.