but in the US AM is quite popular,

Only for some things. Primarily for "talk radio", where hosts pontificate on their favorite topics and field questions from telephone callers. In recent years, this field has become dominated in the US by a character named Rush Limbaugh. He's a very large man with a larger ego, and has a very right-wing (extremely conservative) view of politics. Because of this, I consider the lack of an AM radio in the Empeg to be a beneficial feature.

Once upon a time, "Rush" meant a trio of Canadian virtuoso rock musicians. Now, when you say "Rush" to somebody in the US, you have to specify which one.

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Tony Fabris