I own the Jensen mc-2rr-L model and it sounds great. The H model I believe is the 1/20 step up, whereas the L is 1/10.
Tavish Design uses the Jensen transformers in its Adagio tubed phono preamp. That is the one I'm striving for in the near future.
Choosing the right SUT for my setup
I’ve decided to add a SUT to my setup. My MC carts are a Denon 103R (14 ohms/0.25mV) and an Audio Technica AT-OC9XSL (12 ohms/.4mV). I’m trying to decide between two used SUTs: the Denon AU-300LC and the Denon AU-320, both having a 1:10 ratio. Would loading ideal gain for the 103R and the OC9 be best achieved thru a using a calculator and installing a resistor that can be switched for carts or testing with a trimpot then installing resistor? I’ve also seen writeups where the OC9 is put on a 1:12 SUT and 1:20 for the 103R; from the boards experience is that pushing overload, or its in a good spot?