I'm new to Step Up Transformers

Hello, I don’t think many people understand your question and what your friend is telling you. I personally own 3 preamps that have excellent phonostages. I own 2 high level, very expensive external phonostages that have MM and MC settings. Both external phonostages have Lundahl transformers to step up the signal for MC cartridges.  The point your friend is making, is to try various other Step up Transformers via the MM section of your phonostage. I personally own 7 or 8 SUT’s and have discovered they all have their own unique sound and it takes time to match the perfect SUT with your cartridge. The more options you have, the better the results will be. If you are happy with the built in MC section of your preamp, then enjoy it but if you want to hear things change in sound, just like changing the cartridge affects the sound dramatically, trying different SUT’s can make the sound better or worse as well. I personally am a fan of options.  

The Zesto Andros has the Nobel network included in their circuit, along with loading options designed specifically for that transformer/zobel.

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.

@chipcalzone : The cables from the SUT into the phono stage should be as short as possible to avoid loading down the transformer secondary. This is something that many users of SUT's are unaware of. My Cotter SUT came with fixed output cables of the proper length. 

@lowtubes : I agree! Different SUT's, like different cartridges, have unique sonic attributes. So experimentation is in order! I have five on hand to try, including a Quicksilver.​​

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