Zapco Z.150.4AP 4-Ch. Class AB Audiophile AmplifierThe Z AP Series of Audiophile Amplifiers. Audiophile: An audio fanatic whose sole passion is accurate sound reproduction that brings all the purity of a live performance to recorded music. It is a familiar term with high end home gear like McIntosh or Bryston, but a term always considered unattainable in the automotive environment. Zapco disagrees! In 1974 Zapco began a quest for perfect sonic reproduction. While perfection may be unattainable, the