It is used because the gain of the phono stage is insufficient for the cartridge used. Low output cartridges are popular because MOST think they sound better. The immortal "MC or MM thread" shows that this question will never be settled. Good SUTs sound very good; it is your choice.
why is a step up transformer used
I was wondering what the purpose was of a step up transformer for a phono stage? I have a Krell KPE but it does not seem to have enough gain using the preanmp as a power supply. Any suggestions?