voltage converter and phono stage

No. There are a lot of units out there which run with step up/down units. A lot
of power supplies work worldwide, they are internally soldered for different
mains. When you have a qualified technician, he should be able to check that.

If you can avoid the step down transformer I would. Who is the manufacturer of the Phono Stage and how old is it?

it's a heed quasar. It's just a few months old.

I would like to avoid ANY noise!