This is probably a silly question with an obvious answer to those who know: Why are audio amplifiers seldom powered with switched-mode power supplies? The common exceptions I know of are in cases where there are few other options as in car amps or where an SMPS is for used other sections anyway, as in TVs.
I can understand how the complexity of SMPSes precludes their use in low-power, low-cost products, and how noise may be a problem with certain applications. But what about medium to fairly high powers with line level inputs? Their light weight and the ease of incorporating regulation and overload protection seem to provide attractive advantages over transformers, and volume production could obviate the cost advantage of transformers.