I only have limited experience with SUT's, auditioned an Ortofon SUT once but unfortunately, there was a gain mismatch with my then AT33 PTGii cart so I wasn't convinced that adding one would be an advantage. Then, a very experienced audio buddy of mine told me about
http://www.acoustic-dimension.com/silk-audio/silk-audio-supermalloy-mc-220A-step-up-transformer--pag...Made in Thailand, the few reviews I chanced across online were encouraging, pricing also made it attractive. Bought it blind and based only on that one recommendation and it turned out to be a great addition to my analog chain. I've compared the Silk SUT with the MC section of my phono pre (which uses permalloy transformers) many times and hands down using a SUT into the MM stage of phono smokes it every single time.