Step down transformer (220V to 100/110V) or buy 220V version of Shindo preamp

I really need to buy a Shindo preamp. a) Should I go for a original 220V Shindo preamp (harder to obtain, no local Shindo dealer here) or  b) get a 110/100V version from USA/Japan and use a step-down transformer c) Or get the Shindo dealer to alter the 110V to 220V.

questions:
1) At this level, is there sound degradation if I use a step down transformer?
2) The Shindo dealer will change the 110V to 220V but it will be done by a US tech not Shindo, I wonder if it will lead to some loss. Since soldering and change of resistor will happen. If that's the case I might just buy the 110V version from him.

Any thoughts on using step down transformer in general, does it lead to sound degradation?