Can I use a step up transformer?

Dear Thuchan, How could I know; I own  only two?

You can certainly try a step-up but in my experience they color the sound too much and lose the low end. I've had Sony, Denon (2 kinds, they where the best IMHO), Dynavector, & Fidelity Research, they were great investments, I sold them all for more than I paid so I've not heard everything but I just find a well designed solid state phono preamp much more transparent. I use a Monolithic PS-1 with the PA-1 upgrade power supply, $1100 new with my Dynavector 17D Karat and Grace Ruby FE9+. I've heard better RIAA preamps but only over $4k. I'd love to try a tube preamp but too much money for me right now.

Humand,
matching MCs with the appropriate SUT is not an easy job. If you are using SUTs and they do color the sound, are loosing the low or high end, you definitely have a mismatch. And the result will be like you described.

Working with many phono stages and SUTs I found quite some limitations with 'active' phono stages that 'passive' SUTs overcome.

Dear @thuchan :  For the second time in the thread you posted: 

"""matching MCs with the appropriate SUT is not an easy job. """

first time you said:

""" use perfect matching cart/step up combinations thus precisely align the two facing coils you may enter into a different musical experience . """


and I posted: ""  what to do to " enter in that different musical experience? ""

I think not only me but some other gentlemans are still waiting your " light "/explanation.  Could you do it?, it's a critical analog audio subject.

Again, thank's in advance.

Regards and enjoy the music,
R.

Dear Raul,
I guess you know dealing with parameters in this matching process that we are facing two coils looking at each other, the one of the cart, the other of the SUT. You need harmonizing both in the best way. You know how to do it Raul as you are working in this special field. You also find good descriptions on the web (e.g. Rothwell). What makes it an experimenting job is the different quality of the coils and the windings. I found that good silver like from Silvercore or Kondo do contribute to a fine sound. Also the Jensen, the Joergen Shoe, some of the Ortofon, the Neumann BV 33, the Hashimoto are of excellent quality. Here again the careful winding and production process are of importance. At my Western Electric 618B SUT pure copper of the 30ies of the last century was used, not the reworked industrialized copper some other design come with. The windings are manually done with enough space.
Despite the frequency band is not as high as with modern designs the sound is overwhelming.