use of dc-dc converters in high power amps supply

[guyst]

hello to all,

i would like to get some feedback about using a high power boost converter for several hundred watts psu;
i have many 12V/24V CT transformers but obviously need much more for descent power (AB class).
so, how about using a switching controller with some powerful fets and the right inductor (there is much detailed design info on the dsheets) to do the job?
if the PSRR of the amp is adequate, a big juicy capacitor at the Vout for high current consumption,
and something like LM3481 or any of his friends..
can this be problematic?

and another related thing: that LM3481 can deliver 1A for switching (some others much more), so theoretically
with the right fet and inductor it can drive a significant load. however, in the dsheet the typical applications outputs are quite modest.
why is that?

thanks for your replies!