Please help on toroidal stepdown transformer

[Eddy tech]

hi friends I'm planning to build my fourth amplifier, as i started from 40w, 100w and 200w amps. now i want to step up to 400w and make two of them so that i have 800w stereo amp. My problem is a transformer 55-0-55v ac. i wish to make one on my own for (toroidal) at least 1000 watt ratted. any suggestion please on calculations and requirements. advise me any where that I'm wrong. thanks

 

[AndrewT]

Two 400W amplifiers fed from a common supply will work with a transformer rated from 800VA to 1600VA.

You can use a transformer way outside this range and the amplifiers will still work.

No other maths, nor arithmetic, required.