I should stress that not every step-down transformer would do for hi-end applications. Transformers can impart their own sonics on the sound. The one I recommend is audio-grade, isolation(!) transformer, with low(!) radiation. I measured the radiation from the EI transformers I have here (Hospital grade) and was shocked!. Toroidals have low radiation so always prefer those, especially if you have kids.
Cheers.
Cheers.