WhenI busk I never use amplification,it is imperative to have the goodwill of local shopkeepers.
Inever busk for more than an hour without a break[it gives the shopkeepers a break too]
my voice is loud enough, that like Margaret Barry I dont need amplification.
when busking a very good trick is to stand in an alleyway with wooden doors the wood,and the closed walls act like a microphone .