Guidance for choosing step down transformer for audio gear


I am getting ready to move from the US to Switzerland (120v to 220v) and am putting together my plan for being able to use my current gear with the use of a step down transformer. Most of the details and information needed I have been able to pull off of manufacturer sites and other audio focused forums such as this one but have been unable to find a definitive answer on what wattage of a transformer should be used.

My gear list and max power consumption is listed below:

Amp - NAD M10 500w
Analog Source - Acoustic Signature Primus Turntable 22w
Phono Stage - Lehman Black Cube SE 3w
Speakers - GoldenEar Triton 2+ 1200w

I currently have all of my gear plugged into a Panamax MR4300 which I would like to continue to use for the additional protection and makes cable management a bit easier, (this is why I have the Primus, NAD, and Phono listed above even though you would find that they are 220v compatible if you checked). 

The total power consumption is an easy enough addition of 2,925 watts, where I run into my problem is picking what maximum watt rating for the stepdown transformer is best. I have seen posts that recommend everything from a max wattage to just over the total max power consumption summation to 2x the total all the way up to 6x the total power consumption number. This brings me to my main question of what is the best calculation to use for total gear being used and max wattage rating of the stepdown transformer?

Additionally, the Panamax is protected by a 15 amp fuse or 1800w max consumption (120v x 15 amp), since all of the gear above doesn't current trip the fuse what is the correct way to add up the total power consumption of a set up since I know the gear isn't using their max power draw at all times since that would be significantly over the spec of the 15 amp fuse in the Panamax and even the 20 amp breaker that the outlet pulls from.

Appreciate any guidance on this as I have been unable to find the answer through research.
gouldenear
I could give you a detailed answer, and being practically the only guy here with actual hands on experience from having used one of these things for several decades it would be good solid info. But I just get so sick and tired of then having to put up with all the ignorant blather and its so depressing as it always turns out people vote rather than think and the blatherers out-vote me a hundred to one. So do a search, read my comments, and then if you still have any questions (which you won't, I've explained all this in excruciating detail) please do ask. Off-line, where we won't have to put up with the blatherers.
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goldenear, standard voltage in Switzerland is 230V 50Hz (not 220V) - only 4% lower than max 240V rated for the NAD - not safe.   With transformer it will operate at <50% of max rated voltage (most of Europe had 220V while UK had 240V.  Now Europe is adhering to 230V standard - a compromise).
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dannad,

+10% is customary and listed in my Benchmark AHB2, but M10 specification or back panel says nothing.  They don't even mention frequency.  I'm sure it works at 50Hz, but no specification available.
If we assume that NAD would be completely safe at 230V then I wouldn't bother with additional piece (transformer) and simply sell Panamax (<$300).  In Switzerland I would get something similar or better for 230V (tight non-sacrificial protection).  Transformer is a headache and might limit choices in future, not only by limiting total power available, but also because most of the gear sold in Switzerland will be 230V only.  Such gear can be plugged directly into wall, but then what Panamax is for?  Another protector/conditioner for 230V?   Perhaps operation at 50% of max voltage is safer, but Switzerland is a very civilized country - they don't have lightning :)