You can use a 20db phono step-up transformer, if you want to. You just have to make sure that you have the load set for the MM-type load that the Grado wants(47k).
Grado Statement Series
I have recently purchased a Statement Sonata here on the 'Gon. I currently have Rega pre with only 36.5 dbs. of gain. My question: Can I use a step-up transformer to make up the differnce in gain? Or is new(used) pre-amp in my future? My knowledge is lacking and I have searched the archives to no avail.