How to choose step up transformers?

“Do I need to match up the cartridge and the SUT?”

I would say Yes! The two important numbers in MC cartridge to be aware before you go SUT hunting are the internal impedance and the output voltage. I would suggest reading up on Dave Slagle’s primer on SUT selection,

http://www.intactaudio.com/forum/viewtopic.php?t=752

The two manufacturers I know off that have excelled themselves in providing custom SUT tailored for your cart are,

http://myemia.com/SUT.html

https://www.bobsdevices.com/product-page/sky-cinemag

Lot of folks also like Auditorium A23 with Denon carts.
Hope this helps!

i agree with @lalitk .........if you are a DIY kinda person who gets techie stuff.

if you really want to do it right and are not techie, contact Dave Slagle directly and ask him to recommend which of his SUT’s is right for your cartridge and phono stage.

http://www.myemia.com/SUT.html

in my case, he sent me two to try, then two more, and i’m really happy with the results. i now own 2 of Dave’s SUT’s.

i wish i was smart enough to figure it out on my own, but i could not quite get a handle on it myself even after reading a bunch of stuff. if that is you too, don’t let that push you away from SUT heaven.

Thanks for the reply.  It seems I need to first pick the cartridge then buy the SUT.  But if I change the cartridge, I may need to buy another SUT?

The good news is that SUT matching is not that critical! So if you change your mc cartridge you will still have very good-to- excellent sound quality - just with a different sonic "flavor". That was what the late - and missed! - Art Dudley concluded after years of listening. He mentioned this in one of his many columns!