I'm new to Step Up Transformers

A Zobel network is often used to damp a transformer. But if you change the source impedance, the Zobel network won't be correct.

If you really want it right so the transformer editorializes least, the only way to really know is the procedure at the link I posted earlier.

Actually the best way is to put your cartridge/transformer on a scope and adjust the zobel to minimise ringing. This I would assume is beyond many here.

I actually used the Zesto/Zobel removed from the phono as a test bed - adjusting the zobel for a 40ohm Denon 103D (New) made very little difference to the sound, virtually inaudible, whereas changing the loading was more audible with that transformer ( Jensen ).

The Paua is a moving iron cartridge and will work best with a high-gain phono stage - not an SUT.

This is not true.

Whilst I am not a fan of SUTs, it comes down to the quality of the various options and more importantly whether the high gain phono vs SUT-MM phono can provide the optimum gain and LOAD.

Each of the options has its plusses and minuses.

@jasonbourne71 Facts. I'm using a .75-meter custom-made phono cable between my SUT and phono.

My Hyperion is a moving iron cartridge and it decidedly works best with a low gain phono stage, and my preference is to use an SUT in to the MM input of every phono stage I have tried it with. 

@billstevenson 

Which SUT are you using with the Hyperion ?

Have you compared many ??

Thanks.