Thanks for the replies so far. I'd really like to avoid the use of step down (up?) transformers, I find they're an inelegant solution. I know some electronics shipped to different voltage regions are identical, aside from the power board. Where a switching power supply is not included (as seems to be the case with the components I own), I was hoping to convert the unit itself so that it was indistinguishable from the version that would have been released in this region. I do have a question out to Marantz too, but not overly hopeful of a constructive reply....
You are wrong. The whole power transformers have to be replaced, and they are seldom the same size, so it can't be done. You have to use an external transformer whether you like the look of it or not. Your big mistake was moving the gear to Europe. We would have told you to sell it and buy new, which is the beat approach. Groundings and neutrals are different in Europe, and when you try what you are doing, you often get an incurable hum.
The other issue you will have is that you will not be able to use the FM radio section.
DAB is widespread in Europe which we don't have that in the US. Your receiver is not equipped for DAB. For analog stations the European EQ is 50 microseconds, and in the US 75 microseconds. So even if you find an analog station it won't sound anywhere near correct.
The power consumption of your two units is 800 watts. So you need at least a 1000 watt transformer. However even that is marginal for turn on and peaks etc, but certainly no less than 1000 watts, and a 1200 watts would be better, for better margin.
Basically, this can't be sugar coated. You made a bad decision taking that gear to Europe.
