Class A amps are the least efficient kind. They are bigger heavier and draw more power (per watt output) than the rest so total cost of ownership is high. To make up for that you tend to want speakers that are more efficient. Quality full range hifi speakers that are also more efficient also tend to be larger, heavier and often more expensive as well.
Class A amps from reputable vendors are usually very highly regarded in terms of inherent sound quality.
Class A amps from reputable vendors are usually very highly regarded in terms of inherent sound quality.