amp via transformer 220 - 110 a good idea?

IF the transformer is big enough to handle twice the current draw of the amp (more wouldn't hurt) and of reasonable quality, you should notice no degradation in its sound. As a side benefit, you might well get extra noise reduction--useful if your AC line carries a lot of crud.

I was doing the same thing for a while after taking on a short term assignment in a foreign country. I thought the sound was degraded in many ways. Less dynamic, transparency, top end rolled off early, sound stage was narrower.

I will suggest getting an used 220V amp while you are there and sell it at a small loss so you don't have to deal with voltage issue. In addition to lower sound quality, you also might face premature hardward failure which happened to me. Some equipments are easy to switch voltage and you can bring back to the state afterward.

Thanks for your posts guys. I must admit though that I'm even more confused than in the beginning, as you expressed two completely opposite opinions. Cheers,
Maciek

Malickia. A transformer can work fine and actually give an improvement in sound. What you need to do is to get one that is totally over-spec. i.e. 10 times what your amp is going to require otherwise you’ll end up having the issues Semi describes.

An isolation transformer could drop your noise by 6db and if you have electronic savvy and wire your own, you could wire the secondaries so that you get balanced out.

Have a look at Bruce R’s power supply at http://www.transcendentsound.com/power_supply.htm. He’s is 110 to 110, but you could do something similar with a step down tranny.

Regards
Paul