Anyone use 100v or 220v gear with a transformer?

Tvad,

What amp or preamp are you looking at?

I would think that the smaller x-former would heat up significantly. Depending on the windings, hot coil wire could change the resistive load, thus leading to slight voltage fluctuations. Yes? No? Opinions?

You will probably have to change you main fuses, especially if going from 220v to 110v.

This would involve a small step down from 110-120v to 100v.

Electrically it'll work. Sonically it will not. I can't beleive nobody hears the degradation using a step up/down transformer causes. Its not subtle. I'd try to find a 120v unit instead.

Your power company uses step down transformers themselves. I use a tranformer with my Japanese laserdisc player which is 100v and have not had a problem in the five or six years I have used it. It sounds wonderful by the way. It really makes DVDs sound anemic in general.