Sansui AC with 100 volt ... Plug into 120 volt outlet ?

I have a Sansui Integrated Amp (Model AU 607 Alpha MR)
It was made in Japan for Japanese market only ...100 volt AC ....
My Question:
Can I plug this Amp into a 120 volt outlet...
or do I need a step up transformer to do this safely.
My Tech stated that a step up transformer is not necessary.
Thank you