Green’s Dictionary of Slang

1. to talk loudly, lit. to project amplified music.

1979

Sounds 3 Mar. n.p.: Amping it out like a hard-nosed animated juke-box [KH].

2. (US) to act in a highly neurotic, tense manner; to get angry.

1997		Eble Campus Sl. Apr. 1: amp on – yell at, argue with, get mad at someone or accuse someone of wrong-doing.
2001		J. Stahl Plainclothes Naked (2002) 212: McCardle did not bother asking what that meant. He didn’t want to know. When Zank was amping out like this, it was better not to know.