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!

Find out from the manufacturer if the power transformer in that unit has multiple taps on the primary for changing voltage from 220 to 110Vac.