How to choose step up transformers?

I own five SUTs, including a Mike Sanders Quicksilver - and numerous mc cartridges. Why? For the different sonic "flavors" with different combinations of cartridges and SUTs. 

And for something "different" I also have a Marcof PPA-1 battery-powered SS head amp. This too sounds excellent! 

While a generic SUT covers a broad range of MC carts (2-40 ohms), a purpose built SUT from EMIA and Bob Services will definitely sound better with the cart it was originally spec for. That’s how one ends up with multiple SUT’s. When it comes to Analog, you want to extract every last ounce of goodness from that cart and vinyl.

Glad to see roberjerman loves his vinyl cause he pretty much trashes everything else here :-)

Check out this thread as well,

https://forum.audiogon.com/discussions/tango-step-up-transformers-vs-bob-s-sky-blue-cinemag

@lalitk : Yes, I am critical of most of the claims made for today's Hi End gear! But I am content to live with and use some of the best tube and SS gear of the pre- '90 eras! Three roomfulls, in fact! Plus many TTs and boxes of LPs. And not to forget the three RTR's and boxes of RTR tapes!

I have been using Grado MI's and various MC cartridges since 1976 - so I certainly have experience to draw upon!